Статті в журналах з теми "Slug injection"
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1
Soleimani, Rasa, Jalel Azaiez, Mohammad Zargartalebi, and Ian D. Gates. "Heat transfer analysis of immiscible slug flow-based microchannels: Study of channels with extended surfaces." Physics of Fluids 34, no. 9 (September 2022): 093310. http://dx.doi.org/10.1063/5.0114088.
Повний текст джерелаАнотація:
Immiscible injection of slug(s) into a microchannel with square blocks attached to the bottom surface of the channel is studied using the phase-field approach for interface tracking. It is confirmed that immiscible injection enhances heat transfer by up to 85% compared to miscible injection considering identical thermophysical properties. The differences in the rate of heat removal between immiscible and miscible injection are explained by the hydrodynamics of the system. It is also found that larger injected slug size does not necessarily result in greater heat removal and causes the average Nusselt number to behave non-monotonically, reaching an optimum value at a specific slug length. This non-monotonic trend has been explained by analyzing the hydrodynamics of the system. The effect of the inter-block distance generally showed a monotonic increasing trend for the average Nusselt number, except for a single slug length. This behavior has been explained by the vorticity and Fourier transform analysis. An alternating slug injection configuration has also been analyzed. The analysis of this configuration reveals a non-monotonic behavior of the average Nusselt number vs the number of injected slugs. This non-monotonic behavior shows that for each value of the selected slug length, there is a critical number of slugs, and consequently, a critical slug length for which the average Nusselt number reaches a maximum. The hydrodynamics of the system justifies this non-monotonic behavior. Finally, the friction factor and performance evaluation criterion are presented as a guideline for the design of the microchannels based on flow configuration.
2
Tantianon, Anan, and Falan Srisuriyachai. "Assessment of Surfactant Flooding With Variations of Slug Injection Strategies in Waterflooded Reservoir." International Journal of Advanced Research in Engineering 3, no. 3 (September 27, 2017): 1. http://dx.doi.org/10.24178/ijare.2017.3.3.01.
Повний текст джерелаАнотація:
Injection of surfactant into waterflooded reservoir which has considerably high water saturation may cause a reduction in surfactant efficiency by means of surfactant dilution and adsorption. Therefore, to maintain expected lowest interfacial tension (IFT) condition, large amount of surfactant, which leads to higher cost, is inevitable. Several studies have observed that reduction in surfactant concentration slug at the late time can cause a shift in surface equilibrium, resulting in desorption of retained active surfactant agents and therefore, it is possible to obtain benefit from this phenomenon to achieve longer period of the lowest IFT condition while maintaining the amount of surfactant used. Hence, this study aims to evaluate effects of two-slug surfactant flooding compared to single-slug while maintaining amount of surfactant used constant in waterflooded reservoir. The performance is evaluated based on additional oil recovery using STAR® reservoir simulation program. Simulated results indicated that two-slug surfactant injection yields better oil recovery than conventional single-slug surfactant flooding due to benefit of sacrificial adsorption and desorption process of active surfactant. Selecting type of two-slug surfactant flooding strategy would depend on surfactant concentration of single-slug which is chosen for modification; whereas, the selection of magnitude of concentration contrast between two slugs would depend on placement of surfactant mass ratio.
3
Tan, Li, and Parwinder S. Grewal. "Pathogenicity of Moraxella osloensis, a Bacterium Associated with the Nematode Phasmarhabditis hermaphrodita, to the Slug Deroceras reticulatum." Applied and Environmental Microbiology 67, no. 11 (November 1, 2001): 5010–16. http://dx.doi.org/10.1128/aem.67.11.5010-5016.2001.
Повний текст джерелаАнотація:
ABSTRACT Moraxella osloensis, a gram-negative bacterium, is associated with Phasmarhabditis hermaphrodita, a nematode parasite of slugs. This bacterium-feeding nematode has potential for the biological control of slugs, especially the grey garden slug, Deroceras reticulatum. Infective juveniles of P. hermaphrodita invade the shell cavity of the slug, develop into self-fertilizing hermaphrodites, and produce progeny, resulting in host death. However, the role of the associated bacterium in the pathogenicity of the nematode to the slug is unknown. We discovered that M. osloensis alone is pathogenic toD. reticulatum after injection into the shell cavity or hemocoel of the slug. The bacteria from 60-h cultures were more pathogenic than the bacteria from 40-h cultures, as indicated by the higher and more rapid mortality of the slugs injected with the former. Coinjection of penicillin and streptomycin with the 60-h bacterial culture reduced its pathogenicity to the slug. Further work suggested that the reduction and loss of pathogenicity of the aged infective juveniles of P. hermaphrodita to D. reticulatum result from the loss of M. osloensisfrom the aged nematodes. Also, axenic J1/J2 nematodes were nonpathogenic after injection into the shell cavity. Therefore, we conclude that the bacterium is the sole killing agent of D. reticulatum in the nematode-bacterium complex and thatP. hermaphrodita acts only as a vector to transport the bacterium into the shell cavity of the slug. The identification of the toxic metabolites produced by M. osloensis is being pursued.
4
Gong, Jiakun, Sebastien Vincent-Bonnieu, Ridhwan Z. Kamarul Bahrim, Che A. N. B. Che Mamat, Raj D. Tewari, Mohammad I. Mahamad Amir, Jeroen Groenenboom, Rouhollah Farajzadeh, and William R. Rossen. "Injectivity of Multiple Slugs in Surfactant Alternating Gas Foam EOR: A CT Scan Study." SPE Journal 25, no. 02 (February 4, 2020): 895–906. http://dx.doi.org/10.2118/199888-pa.
Повний текст джерелаАнотація:
Summary A surfactant alternating gas (SAG) process is often the injection method for foam, on the basis of its improved injectivity over direct foam injection. In a previous study, we reported coreflood experiments on liquid injectivity after foam flooding and liquid injectivity after injection of a gas slug following steady-state foam. Results showed that a period of gas injection is important for the subsequent liquid injectivity. However, the effects of multiple gas and liquid slugs were not explored. In this paper, we present a coreflood study of injectivities of multiple gas and liquid slugs in an SAG process in a field core. Nitrogen and surfactant solution are either coinjected or injected separately into the sandstone core sample. The experiments are conducted at an elevated temperature of 90°C with a backpressure of 40 bar. Differential pressures are measured to quantify gas and liquid injectivities. Computed tomography (CT) scanning is applied to relate water saturation to mobility. During the injection of a large gas slug following foam, a bank in which foam completely collapses or greatly weakens forms near the inlet and propagates slowly downstream. During the subsequent period of liquid injection, liquid flows through the collapsed-foam bank much more easily than further downstream. Beyond the collapsed-foam region, liquid first imbibes into the whole cross section. In this region, liquid flows mainly through a finger of high liquid saturation. Our CT results suggest a revision of our earlier interpretation; the process of gas dissolution does not merely follow fingering but is evidently directly involved in the fingering process. Our results suggest that, in radial flow, the small region of foam collapse very near the well greatly improves injectivity. The subsequent gas and liquid slugs behave near the wellbore, affecting injectivity, in a way similar to the first slugs. Thus, the behavior and modeling of the first gas slug and first subsequent liquid slug is representative of near-well behavior in an SAG process. The trends observed in our previous work are reproduced in a low-permeability field core.
5
Adegboyega B. Ehinmowo and Ndubusi U. Okereke. "OPTIMIZATION OF RISERBASE GAS INJECTION FOR SLUG FLOW ATTENUATION." JOURNAL OF THE NIGERIAN SOCIETY OF CHEMICAL ENGINEERS 37, no. 3 (September 30, 2022): 43–49. http://dx.doi.org/10.51975/22370306.som.
Повний текст джерелаАнотація:
A new approach for the optimization of riserbase gas injection for slug flow attenuation has been proposed. Riserbase gas injection is an established method for slug flow mitigation, however it can be expensive due to the high volume of gas required and the cost of compression. In this study, optimum gas volumes required to stabilise a range of unstable slug flow conditions were obtained using bifurcation maps. The results showed that at the bifurcation point, minimum gas injection volume is required to achieve flow stability. This study established that the optimum gas volume required is dependent on the type of slug flow. For a very high frequency slug flow at high flow rate more volume of gas up to 100kg/s is required to achieve stability while slug flow at moderate flow rate could need up to 30kg/s and slug at low flow rate required about 6 kg/s to achieve stability. The developed approach in this work can help reduce the overall cost of gas injection for slug flow mitigation. Keywords: Slug attenuation; Bifurcation; Gas injection; slug flow; multiphase flow.
6
Tuncharoen, Warut, and Falan Srisuriyachai. "Evaluation of Polymer Alternating Waterflooding in Multilayered Heterogeneous Waterflooded Reservoir." MATEC Web of Conferences 171 (2018): 04001. http://dx.doi.org/10.1051/matecconf/201817104001.
Повний текст джерелаАнотація:
Polymer flooding is widely implemented to improve oil recovery since polymer can increase sweep efficiency and smoothen heterogeneous reservoir profile. However, polymer solution is somewhat difficult to be injected due to high viscosity and thus, water slug is recommended to be injected before and during polymer injection in order to increase an ease of injecting this viscous fluid into the wellbore. In this study, numerical simulation is performed to determine the most appropriate operating parameters to maximize oil recovery. The results show that pre-flushed water should be injected until water breakthrough while alternating water slug size should be as low as 5% of polymer slug size. Concentration for each polymer slugs should be kept constant and recommended number of alternative cycles is 2. Combining these operating parameters altogether contributes to oil recovery of 53.69% whereas single-slug polymer flooding provides only 53.04% which is equivalent to 8,000 STB of oil gain.
7
Qian, Jin-yuan, Min-rui Chen, Zan Wu, Zhi-jiang Jin, and Bengt Sunden. "Effects of a Dynamic Injection Flow Rate on Slug Generation in a Cross-Junction Square Microchannel." Processes 7, no. 10 (October 18, 2019): 765. http://dx.doi.org/10.3390/pr7100765.
Повний текст джерелаАнотація:
The injection flow rates of two liquid phases play a decisive role in the slug generation of the liquid-liquid slug flow. However, most injection flow rates so far have been constant. In order to investigate the effects of dynamic injection flow rates on the slug generation, including the slug size, separation distance and slug generation cycle time, a transient numerical model of a cross-junction square microchannel is established. The Volume of Fluid method is adopted to simulate the interface between two phases, i.e., butanol and water. The model is validated by experiments at a constant injection flow rate. Three different types of dynamic injection flow rates are applied for butanol, which are triangle, rectangular and sine wave flow rates. The dynamic injection flow rate cycles, which are related to the constant slug generation cycle time t0, are investigated. Results show that when the cycle of the disperse phase flow rate is larger than t0, the slug generation changes periodically, and the period is influenced by the cycle of the disperse phase flow rate. Among the three kinds of dynamic disperse flow rate, the rectangular wave influences the slug size most significantly, while the triangle wave influences the separation distance and the slug generation time more prominently.
8
Zhang, Ji Hong, Zhi Ming Zhang, Xi Ling Chen, Qing Bin He, and Jin Feng Li. "Study on Influence of Injection Method on the Effect of Oil Displacement of Nanometer Microspheres." Advanced Materials Research 734-737 (August 2013): 1272–75. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.1272.
Повний текст джерелаАнотація:
Nanometer microspheres injection is a new deep profile control technology. Nanometer microspheres could inflate with water, resulting in plugging step by step in reservoirs, which could improve the swept efficiency in the reservoir and enhance oil recovery. By using non-homogeneous rectangular core, oil displacement efficiency experiment was conducted for studying the influence of different injection methods on the effect of injection nanometer microspheres. The experimental result shows that, compared with development effect of single-slug injection or triple-slug injection, the one of double-slug injection is better. Nanometer microspheres can enhance oil recovery significantly in medium and low permeability reservoir.
9
Zanganeh, M. Namdar, and W. R. R. Rossen. "Optimization of Foam Enhanced Oil Recovery: Balancing Sweep and Injectivity." SPE Reservoir Evaluation & Engineering 16, no. 01 (January 30, 2013): 51–59. http://dx.doi.org/10.2118/163109-pa.
Повний текст джерелаАнотація:
Summary Foam is a means of improving sweep efficiency that reduces the gas mobility by capturing gas in foam bubbles and hindering its movement. Foam enhanced-oil-recovery (EOR) techniques are relatively expensive; hence, it is important to optimize their performance. We present a case study on the conflict between mobility control and injectivity in optimizing oil recovery in a foam EOR process in a simple 3D reservoir with constrained injection and production pressures. Specifically, we examine a surfactant-alternating-gas (SAG) process in which the surfactant-slug size is optimized. The maximum oil recovery is obtained with a surfactant slug just sufficient to advance the foam front just short of the production well. In other words, the reservoir is partially unswept by foam at the optimum surfactant-slug size. If a larger surfactant slug is used and the foam front breaks through to the production well, productivity index (PI) is seriously reduced and oil recovery is less than optimal: The benefit of sweeping the far corners of the pattern does not compensate for the harm to PI. A similar effect occurs near the injection well: Small surfactant slugs harm injectivity with little or no benefit to sweep. Larger slugs give better sweep with only a modest decrease in injectivity until the foam front approaches the production well. In some cases, SAG is inferior to gasflood (Namdar Zanganeh 2011).
10
Mohammadikharkeshi, Mobina, Ramin Dabirian, Ram S. Mohan, and Ovadia Shoham. "Experimental Study and Modeling of Slug Dissipation in a Horizontal Enlarged Impacting Tee-Junction." SPE Journal 25, no. 05 (June 1, 2020): 2508–20. http://dx.doi.org/10.2118/190131-pa.
Повний текст джерелаАнотація:
Summary A novel experimental and theoretical study on slug dissipation in a horizontal enlarged impacting tee-junction (EIT) is carried out. Both flowing-slug injection and stationary-slug injection into the EIT are studied, and the effects of inlet slug length and liquid-phase fluid properties on the slug dissipation in the EIT are investigated. A total of 161 experimental data are acquired for air-water and air-oil flow. The flowing-slug data (with a horizontal inlet) show that the slug dissipation length increases with increasing mixture velocity, demonstrating a nonlinear trend with a steeper slope at lower mixture velocities. The effect of superficial gas velocity on the slug dissipation length is more pronounced compared with the effect of superficial liquid velocity. For stationary-slug injection into the EIT (with a 5° upward inclined inlet), the injected slug lengths vary between 40d to 100d (d is the inlet diameter). The data reveal that, when increasing the superficial gas velocity or the inlet slug size, the dissipation length in the EIT branches increases. For this case, the ratio of the slug dissipation length to the inlet slug length is higher for air-water compared with air-oil. A slug dissipation model is developed using the slug-tracking approach, which is based on the flow mechanisms of liquid shedding at the back of the slug and liquid drainage and penetration of bubble turning at the front of the slug. These phenomena result in different translational velocities at the back and the front of the slug, which result in the dissipation of the slug body. Evaluation of model predictions against the acquired experimental data shows an average absolute relative error of less than 11%.
11
Krima, Hazem, Yi Cao, and Liyun Lao. "Gas Injection for Hydrodynamic Slug Control." IFAC Proceedings Volumes 45, no. 8 (2012): 116–21. http://dx.doi.org/10.3182/20120531-2-no-4020.00002.
Повний текст джерела
12
Kite, Geoff. "Computerized streamflow measurement using slug injection." Hydrological Processes 7, no. 2 (April 1993): 227–33. http://dx.doi.org/10.1002/hyp.3360070212.
Повний текст джерела
13
Du, Jian Fen, Jing Chen Ding, Ping Guo, and Yu Hong Du. "Study on Long-Core Experiment of Gas Driving in Dual-Media Reservoir." Advanced Materials Research 524-527 (May 2012): 1591–97. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.1591.
Повний текст джерелаАнотація:
Reservoir X is a fractured-porous dual-media reservoir. According to the geological conditions and exploration and development statuses of reservoir X, this paper designs a long-core experiment and then carries it on. As a result, the diffeSubscript textrent enhance displacement efficiency effects under different driving methods (water flooding, gas flooding, WAG, pulsed gas injection, gas slug flooding) and different driving media (flue gas, CO2) are obtained. The results show that among all those driving methods, water alternating CO2 injection (WAG) reaches the best effect. WAG has an injection rate of 0.8HCPV and enhances displacement efficiency by 26.93% on the basis of water flooding. The injection rate of gas slug/water flooding after CO2 slug flooding is 0.3HCPV and these two methods have similar good results, 13.66% and 13.95% respectively. So considering the economic factor, we draw a conclusion that water flooding after CO2 slug flooding is the optimum choice.
14
Zhang, Ji Hong, Yu Wang, Xi Ling Chen, Zi Wei Qu, and Dong Ke Qin. "The Effect of Following Water after Polymer Flooding on the Displacement Efficiency with Alternately Injecting Slug of Gel and Polymer/Surfactant." Advanced Materials Research 734-737 (August 2013): 1290–93. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.1290.
Повний текст джерелаАнотація:
Aiming at the development of remaining oil after polymer flooding, the author develops an oil displacement technology, alternately injecting the slug of the gel and polymer/surfactant compound system, which can advanced improve the remained oil after polymer flooding. By using the artificial large flat-panel model, the oil displacement experiments are carried on to study the injection characteristics and the displacement efficiency of the alternately injecting the slug of gel and polymer/surfactant compound system, and whether the following water should be injected after polymer flooding has been discussed. The experimental results show that, the recovery of alternately injecting the gel and polymer/surfactant slug after polymer flooding could enhance recovery more than 10% on the basis of polymer flooding, the following water after polymer flooding has a little impact on the final recovery but increasing time and the difficulty of development. Therefore, these results provide the technology that alternately injecting the slug of the gel and polymer/surfactant could advance develop the residual oil and enhance the recovery after polymer flooding.
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Wang, Fulin, Tao Yang, Yunfei Zhao, Yanjun Fang, Fuli Wang, Gaojun Shan, and Guangsheng Cao. "Optimization of development mode of asphalt profile control based on numerical simulation and study of its mechanism." Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 75 (2020): 30. http://dx.doi.org/10.2516/ogst/2020020.
Повний текст джерелаАнотація:
Asphalt profile control is an effective method, which can further improve oil recovery of reservoir polymer flooded, it has a lot of advantages including high strength profile control, seal strata formation efficiency, low cost and no pollution, but there has not a perfect evaluation system for its development mode. The effect of different concentration, injection rate, radius of profile control, the timing of profile and segment combination way on the oil displacement effect of the asphalt profile control were researched using numerical simulation method on actual typical well area in Daqing oilfield, and the mechanism of asphalt profile control was studied in detail. According to the results of laboratory test, the largest Enhanced Oil Recovery (EOR) of asphalt was obtained at injection concentration 4000 mg/L, and the best combination was “high–low–high” concentration slug mode. According to the results of numerical simulation, the best concentration, injection rate, radius of profile control and injection timing were 4000 mg/L, 0.15 PV/a (Pore Volume [PV], m3), 1/2 of well spacing and 96% water cut in single slug of asphalt injection system, when the injection condition was multiple slug, the “high–low–high” slug combination mode was the best injection mode. These results could provide effective development basis for asphalt profile control after polymer flooding in thick oil layers.
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Fayyadh, Ekhlas, Nibras Mahdi, and Ali Mohammed. "The effect of air injection system on airlift pump performance." FME Transactions 48, no. 4 (2020): 800–807. http://dx.doi.org/10.5937/fme2004800f.
Повний текст джерелаАнотація:
In the current study, a novel design of an air injection system for an airlift pump was designed and tested. The pump has a circular cross-section and composed of three parts; suction pipe, injection system, and riser pipe. The riser pipe has a diameter of 31.7 mm and a length of 2 m. The performance of the pump was tested using different submergence ratios, ranging from 0.15 to 0.3, and the injected airflow rate was ranging from 1.65 kg/h to 13.32 kg/h. The results showed that both the airflow rate and the submergence ratio have a significant effect on the capacity and performance of the pump. Besides, it was found that the best range of pump efficiency was in the slug and slug-churn flow regimes. Moreover, the highest efficiency was at the most significant submergence ratio of 0.3. A reasonable enhancement in water flow rate was achieved using the current air injection design when compared with the conventional airlift pump injections system.
17
Dormann, D., T. Abe, C. J. Weijer, and J. Williams. "Inducible nuclear translocation of a STAT protein in Dictyostelium prespore cells: implications for morphogenesis and cell-type regulation." Development 128, no. 7 (April 1, 2001): 1081–88. http://dx.doi.org/10.1242/dev.128.7.1081.
Повний текст джерелаАнотація:
Dd-STATa, the Dictyostelium STAT (signal transducer and activator of transcription) protein, is selectively localised in the nuclei of a small subset of prestalk cells located in the slug tip. Injection of cAMP into the extracellular spaces in the rear of the slug induces rapid nuclear translocation of a Dd-GFP:STATa fusion protein in prespore cells surrounding the site of injection. This suggests that cAMP signals that emanate from the tip direct the localised nuclear accumulation of Dd-STATa. It also shows that prespore cells are competent to respond to cAMP, by Dd-STATa activation, and it implies that cAMP signalling is in some way limiting in the rear of the slug. Co-injection of a specific inhibitor of the cAR1 serpentine cAMP receptor almost completely prevents the cAMP-induced nuclear translocation, showing that most or all of the cAMP signal is transduced by cAR1. Dd-GFP:STATa also rapidly translocates into the nuclei of cells adjoining the front and back cut edges when a slug is bisected. Less severe mechanical disturbances, such as pricking the rear of a slug with an unfilled micropipette, also cause a more limited nuclear translocation of Dd-GFP:STATa. We propose that these signalling events form part of a repair mechanism that is activated when the migrating slug suffers mechanical damage.
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Dormann, Dirk, and Cornelis J. Weijer. "Propagating chemoattractant waves coordinate periodic cell movement inDictyosteliumslugs." Development 128, no. 22 (November 15, 2001): 4535–43. http://dx.doi.org/10.1242/dev.128.22.4535.
Повний текст джерелаАнотація:
Migration and behaviour of Dictyostelium slugs results from coordinated movement of its constituent cells. It has been proposed that cell movement is controlled by propagating waves of cAMP as during aggregation and in the mound. We report the existence of optical density waves in slugs; they are initiated in the tip and propagate backwards. The waves reflect periodic cell movement and are mediated by cAMP, as injection of cAMP or cAMP phosphodiesterase disrupts wave propagation and results in effects on cell movement and, therefore, slug migration. Inhibiting the function of the cAMP receptor cAR1 blocks wave propagation, showing that the signal is mediated by cAR1. Wave initiation is strictly dependent on the tip; in decapitated slugs no new waves are initiated and slug movement stops until a new tip regenerates. Isolated tips continue to migrate while producing waves. We conclude from these observations that the tip acts as a pacemaker for cAMP waves that coordinate cell movement in slugs.Movies available on-line
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Luo, Yue, Ding Wang, Lei Bai, and Ke Jian Zha. "Research and Application of Deep Profile Control & Oil Displacement by Polymer Gel - Surfactant in High Salinity Oilfield." Applied Mechanics and Materials 318 (May 2013): 491–95. http://dx.doi.org/10.4028/www.scientific.net/amm.318.491.
Повний текст джерелаАнотація:
A polymer gel-surfactant composition profile control technology has been developed, basing on the high salinity, especially high levels of Ca2+, Mg2+ in the injection water of the Hongshanzui oilfield. The construction parameters of deep profile control & oil displacement have been studied by performing core displacement experiments. The results show that the ratio of polymer gel slug and active agents slug is 1:0.3, the best ratio of strong polymer gel, medium polymer gel and weak polymer gel slug is 4:3:3. The way of combination is stronger gel slug + surfactant slug + in strong gel slug + weak gel slug + surfactant slug + strong gel sealing slug. The application effect of this technology in Hongshanzui oilfield is remarkable, the 12 tune flooding group daily oil production rose from 85t to 130t and the liquid water content decreased from 75% to 67%.
20
Fedorov, Konstantin Mikhailovich, Alexander Yanovich Gilmanov, Alexander Pavlovich Shevelev, Alexander Vyacheslavovich Kobyashev, and Denis Alekseevich Anuriev. "A Theoretical Analysis of Profile Conformance Improvement Due to Suspension Injection." Mathematics 9, no. 15 (July 22, 2021): 1727. http://dx.doi.org/10.3390/math9151727.
Повний текст джерелаАнотація:
This study is focused on a solution for the problem of suspension penetration in a porous formation. Such a solution forms the basis of injection profile diversion technology for oil reservoir sweep improvement. A conventional model of deep-bed suspension flow was used to describe the suspension injection process. The suspension slug was followed by water injection, and the inflow injection profile before and after treatment was investigated. For the first time, the criteria that determine the effectiveness of the inflow profile improvement process are introduced. The effect of the suspension filtration coefficient on the particle penetration depth was studied. A specific filtration coefficient value for the maximum penetration depth was achieved. The obtained analytical solution was generalized on multi-reservoir strata with poor interlayer crosslinking. The efficiency of profile conformance improvement was described by the differences in the root-mean-square deviations of the inflow velocities in interlayers from mean values before and after the treatment. It was shown that the complex criterion of suspension treatment efficiency should include a reduction in total injectivity. An increase in suspension slug volume improves the injectivity profile but decreases the total injectivity of an injector.
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Huang, Hai. "Laboratory Studies of Immiscible N2 WAG Flooding for Low Permeability Reservoir of Ordos Basin." Advanced Materials Research 347-353 (October 2011): 1663–68. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.1663.
Повний текст джерелаАнотація:
This paper presents experimental work that quantifies the effect of water-alternating-gas (WAG) variables on the immiscible N2 flooding process for low permeability reservoir of Ordos Basin. Many experiments were done with the sand-packed model under the formation condition. The results may be used to determine such parameters as injection pattern, WAG radio, and the number of WAG slugs. Analysis of the relative efficiency of each WAG slug is discussed.
22
Al Ayesh, A. H., R. Salazar, R. Farajzadeh, S. Vincent-Bonnieu, and W. R. Rossen. "Foam Diversion in Heterogeneous Reservoirs: Effect of Permeability and Injection Method." SPE Journal 22, no. 05 (April 10, 2017): 1402–15. http://dx.doi.org/10.2118/179650-pa.
Повний текст джерелаАнотація:
Summary Foam can divert flow from higher- to lower-permeability layers and thereby improve the injection profile in gas-injection enhanced oil recovery (EOR). This paper compares two methods of foam injection, surfactant-alternating-gas (SAG) and coinjection of gas and surfactant solution, in their abilities to improve injection profiles in heterogeneous reservoirs. We examine the effects of these two injection methods on diversion by use of fractional-flow modeling. The foam-model parameters for four sandstone formations ranging in permeability from 6 to 1,900 md presented by Kapetas et al. (2015) are used to represent a hypothetical reservoir containing four noncommunicating layers. Permeability affects both the mobility reduction of wet foam in the low-quality-foam regime and the limiting capillary pressure at which foam collapses. The effectiveness of diversion varies greatly with the injection method. In a SAG process, diversion of the first slug of gas depends on foam behavior at very-high foam quality. Mobility in the foam bank during gas injection depends on the nature of a shock front that bypasses most foam qualities usually studied in the laboratory. The foam with the lowest mobility at fixed foam quality does not necessarily give the lowest mobility in a SAG process. In particular, diversion in SAG depends on how and whether foam collapses at low water saturation; this property varies greatly among the foams reported by Kapetas et al. (2015). Moreover, diversion depends on the size of the surfactant slug received by each layer before gas injection. This favors diversion away from high-permeability layers that receive a large surfactant slug. However, there is an optimum surfactant-slug size: Too little surfactant and diversion from high-permeability layers is not effective, whereas with too much, mobility is reduced in low-permeability layers. For a SAG process, injectivity and diversion depend critically on whether foam collapses completely at irreducible water saturation. In addition, we show the diversion expected in a foam-injection process as a function of foam quality. The faster propagation of surfactant and foam in the higher-permeability layers aids in diversion, as expected. This depends on foam quality and non-Newtonian foam mobility and varies with injection time. Injectivity is extremely poor with foam injection for these extremely strong foams, but for some SAG foam processes with effective diversion it is better than injectivity in a waterflood.
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Santoso, Ryan, Victor Torrealba, and Hussein Hoteit. "Investigation of an Improved Polymer Flooding Scheme by Compositionally-Tuned Slugs." Processes 8, no. 2 (February 6, 2020): 197. http://dx.doi.org/10.3390/pr8020197.
Повний текст джерелаАнотація:
Polymer flooding is an effective enhanced oil recovery technology used to reduce the mobility ratio and improve sweep efficiency. A new polymer injection scheme is investigated that relies on the cyclical injection of low-salinity, low-concentration polymer slugs chased by high-salinity, high-concentration polymer slugs. The effectiveness of the process is a function of several reservoir and design parameters related to polymer type, concentration, salinity, and reservoir heterogeneity. We use reservoir simulations and design-of-experiments (DoE) to investigate the effectiveness of the proposed polymer injection scheme. We show how key objective functions, such as recovery factor and injectivity, are impacted by the reservoir and design parameters. In this study, simulations showed that the new slug-based process was always superior to the reference polymer injection scheme using the traditional continuous injection scheme. Our results show that the process is most effective when the polymer weight is high, corresponding to large inaccessible pore-volumes, which enhances polymer acceleration. High vertical heterogeneity typically reduces the process performance because of increased mixing in the reservoir. The significance of this process is that it allows for increased polymer solution viscosity in the reservoir without increasing the total mass of polymer, and without impairing polymer injectivity at the well.
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Wang, Wendong, Fankun Meng, Yuliang Su, Lei Hou, Xueyu Geng, Yongmao Hao, and Lei Li. "A Simplified Capillary Bundle Model for CO2-Alternating-Water Injection Using an Equivalent Resistance Method." Geofluids 2020 (November 25, 2020): 1–14. http://dx.doi.org/10.1155/2020/8836287.
Повний текст джерелаАнотація:
CO2-alternating-water injection is an effective way of enhancing recovery for low-permeability oil reservoirs. The injection process is one of the essential issues that are facing severe challenges because of the low permeability and poor pore space connectivity. Previous researchers mentioned that water injection ability could be decreased by around 20% after the CO2-flooding; hence, it is necessary to quantify the water injectivity variation during an alternated injection process. In this paper, a CO2 convection-diffusion model is established based on the seepage law of CO2 and dissipation effect. The relationship between the width of miscible flooding and injection time is defined. Besides, an equivalent resistance method is introduced for developing a capillary bundle model for featuring an unequal diameter for CO2 water vapor alternate flooding. CO2-oil and CO2-water interactions are analyzed using the new model. The effects of oil viscosity, pore throat ratio, CO2 slug size, and equivalent permeability of the capillary bundle on water injection are analyzed. The result indicates that water injection ability increases with the rise of CO2 slug size and equivalent permeability of the capillary bundle and decreases with the increase of viscosity and pore throat ratio.
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Abdul Hamid, S. A., and A. H. Muggeridge. "Analytical solution of polymer slug injection with viscous fingering." Computational Geosciences 22, no. 3 (February 8, 2018): 711–23. http://dx.doi.org/10.1007/s10596-018-9721-0.
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Tan, Li, and Parwinder S. Grewal. "Endotoxin Activity of Moraxella osloensis against the Grey Garden Slug, Deroceras reticulatum." Applied and Environmental Microbiology 68, no. 8 (August 2002): 3943–47. http://dx.doi.org/10.1128/aem.68.8.3943-3947.2002.
Повний текст джерелаАнотація:
ABSTRACT Moraxella osloensis is a gram-negative bacterium associated with Phasmarhabditis hermaphrodita, a slug-parasitic nematode that has prospects for biological control of mollusk pests, especially the grey garden slug, Deroceras reticulatum. This bacterium-feeding nematode acts as a vector that transports M. osloensis into the shell cavity of the slug, and the bacterium is the killing agent in the nematode-bacterium complex. We discovered that M. osloensis produces an endotoxin(s), which is tolerant to heat and protease treatments and kills the slug after injection into the shell cavity. Washed or broken cells treated with penicillin and streptomycin from 3-day M. osloensis cultures were more pathogenic than similar cells from 2-day M. osloensis cultures. However, heat and protease treatments and 2 days of storage at 22°C increased the endotoxin activity of the young broken cells but not the endotoxin activity of the young washed cells treated with the antibiotics. This suggests that there may be a proteinaceous substance(s) that is structurally associated with the endotoxin(s) and masks its toxicity in the young bacterial cells. Moreover, 2 days of storage of the young washed bacterial cells at 22°C enhanced their endotoxin activity if they were not treated with the antibiotics. Furthermore, purified lipopolysaccharide (LPS) from the 3-day M. osloensis cultures was toxic to slugs, with an estimated 50% lethal dose of 48 μg per slug, thus demonstrating that the LPS of M. osloensis is an endotoxin that is active against D. reticulatum. This appears to be the first report of a biological toxin that is active against mollusks.
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McGuire, P. L., R. S. Redman, W. L. Mathews, and S. R. Carhart. "Unconventional Miscible Enhanced Oil Recovery Experience at Prudhoe Bay." SPE Reservoir Evaluation & Engineering 2, no. 03 (June 1, 1999): 222–29. http://dx.doi.org/10.2118/56849-pa.
Повний текст джерелаАнотація:
Summary This paper summarizes the conceptual development, reservoir simulation, and field testing of an unconventional application of the miscible enhanced oil recovery (EOR) process at Prudhoe Bay. The miscible injectant stimulation treatment (MIST) process involves completing a well at the bottom of a thick, continuous, watered-out interval. A horizontal lateral is drilled along the base of the reservoir, and a large slug of miscible injectant (MI) is injected, followed by a small slug of chase water. The MI sweeps rock not contacted by previous MI injection and drives EOR oil to offset producers. MI is injected sequentially into several intervals along the lateral to mobilize EOR oil from previously unswept areas. The lateral well is then returned to normal production or injection service. Simulation data indicate that each MIST well could recover up to 1,000 MSTB of incremental oil at initial rates of up to 1,000 STB/D. Field results have been encouraging. Incremental EOR from the three MIST lateral wells is over 2.1 MMSTB, with peak production rates of about 6,000 STB/D. Background The Prudhoe Bay field, located on the north coast of Alaska, is the largest oilfield in North America, with total estimated reserves of roughly 13 billion barrels and a current production rate of approximately 700 MSTB/D. The field is overlaid by a large gas cap, and the majority of the field is being produced by gravity drainage. Waterflood and miscible enhanced oil recovery (EOR) operations at Prudhoe Bay, which are confined to the downstructure and peripheral areas of the field, are producing roughly 300 MSTB/D. Prudhoe Bay EOR began in late-1982 with an 11-pattern pilot project. The Prudhoe Bay Miscible Gas Project (PBMGP) was initiated in 1987, and now consists of about 130 patterns (Fig. 1). The patterns are typically inverted nine-spots with 80-acre well spacing. The PBMGP currently has a miscible injectant rate of over 500 million scf/D at an average water-alternating-gas (WAG) ratio of about 3:1. The Sadlerochit Group, the major productive interval of the field, includes a thick section composed of high permeability fluvial sands and interbedded shales. In the Flow Station 2 (FS-2) area, these shales create up to four completely isolated flow intervals. Fig. 2 is a detailed map of the FS-2 area showing the MIST wells. A type log of this area is shown in Fig. 3. MIST Concept The Victor hydraulic interval, consisting of Zones 2B, 2C, 3, and part of 4A, is typically about 150 ft thick with few, if any, extensive shales or other vertical permeability barriers. MI is injected throughout the section, while producers are typically completed near the top of the reservoir, since the bottom is completely watered out. The WAG flood is strongly gravity dominated, with rapid vertical segregation of the MI. Horizontal flow in the reservoir is dominated by very thin, extremely high permeability thief zones, which usually occur in the upper half of the Victor. The MI sweeps oil near the injection wellbore, but leaves large areas of the reservoir unaffected. The actual MI sweep efficiency in the Victor was determined by coring well 3-18A, and has been thoroughly documented in a previous paper.1 A history-matched, fully compositional reservoir simulation of WAG in the Victor showed a very limited area in which EOR oil was actually mobilized. Although the entire interval was open to injection, solvent did not contact the bottom 100 ft of the interval. Simulation studies showed that recovery could be increased by utilizing an optimized WAG process. In this optimized WAG, a large MI slug is injected into the bottom 20 to 30 ft of the Victor interval. The entire interval is then perforated for subsequent WAG cycles. Fig. 4 is a cross-section map of oil saturation showing the increased sweep due to optimized WAG. This process was implemented in well 3-18A, which received a 9.5 Bscf solvent slug between September 1994, and June 1995. Well 3-25A responded strongly, with incremental EOR rates of up to 2,000 STB/D, as shown in Fig. 5. Operational issues and wellwork complicated the analysis, but it appears that the large MI slug was responsible for over one million barrels of incremental EOR production from the 3-18A pattern. Even with the optimized WAG, most of the interval is not affected by MI. This unaffected area is the target for MIST. In the vertical MIST process, a production well is temporarily converted to injection by squeezing the perforations at the top of the Victor, then perforating near the base of the reservoir. A large slug of MI (from 1 to 4 Bscf) is injected at high rates (about 40 MMscf/D). The solvent slug is followed by a short period of water injection, which insures safe well operations and drives the MI slug deeper into the reservoir. The bottom perforations are covered with sand or by a bridge plug, and the well is recompleted as a producer at the top of the Victor. In the lateral MIST process, a horizontal lateral is drilled along the base of the reservoir from either a production or injection well. MI is injected sequentially into several intervals (MI "bulbs") along the lateral to mobilize EOR oil in unswept areas. Because gravity segregation is dominant, the MI can sweep a much larger reservoir volume by injecting at full well rates into each bulb separately, rather than injecting MI along the entire length of the well at once. This results in multiple point sources, each of which has a high viscous-to-gravity ratio (VGR), rather than a single line source with a low VGR. Each slug of MI is about 3 Bscf, and is injected as quickly as possible (typically about 30 MMscf/D). Each solvent slug is followed by a short period of chase water injection. After injection for each interval is completed, a bridge plug is set and the next interval is perforated. The lateral well is then returned to normal production or injection service. Fig. 6 illustrates both MIST processes.
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Christensen, J. R., E. H. Stenby, and A. Skauge. "Review of WAG Field Experience." SPE Reservoir Evaluation & Engineering 4, no. 02 (April 1, 2001): 97–106. http://dx.doi.org/10.2118/71203-pa.
Повний текст джерелаАнотація:
Summary In recent years there has been an increasing interest in water-alternating-gas (WAG) processes, both miscible and immiscible. WAG injection is an oil recovery method initially aimed to improve sweep efficiency during gas injection. In some recent applications produced hydrocarbon gas has been reinjected in water-injection wells with the aim of improving oil recovery and pressure maintenance. Oil recovery by WAG injection has been attributed to contact of unswept zones, especially recovery of attic or cellar oil by exploiting the segregation of gas to the top or the accumulating of water toward the bottom. Because the residual oil after gasflooding is normally lower than the residual oil after waterflooding, and three-phase zones may obtain lower remaining oil saturation, WAG injection has the potential for increased microscopic displacement efficiency. Thus, WAG injection can lead to improved oil recovery by combining better mobility control and contacting unswept zones, and by leading to improved microscopic displacement. This study is a review of the WAG field experience as it is found in the literature today,1–108 from the first reported WAG injection in 1957 in Canada to the new experience from the North Sea. About 60 fields have been reviewed. Both onshore and offshore projects have been included, as well as WAG injections with hydrocarbon or nonhydrocarbon gases. Well spacing is very different from onshore projects, where fine patterns often are applied, to offshore projects, where well spacing is in the order of 1000 m. For the fields reviewed, a common trend for the successful injections is an increased oil recovery in the range of 5 to 10% of the oil initially in place (OIIP). Very few field trials have been reported as unsuccessful, but operational problems are often noted. Though the injectivity and production problems are generally not detrimental for the WAG process, special attention has been given to breakthrough of injected phases (water or gas). Improved oil recovery by WAG injection is discussed as influenced by rock type, injection strategy, miscible/immiscible gas, and well spacing. Introduction The WAG injection was originally proposed as a method to improve sweep of gas injection, mainly by using the water to control the mobility of the displacement and to stabilize the front. Because the microscopic displacement of the oil by gas is normally better than by water, the WAG injection combines the improved displacement efficiency of the gas flooding with an improved macroscopic sweep by water injection. This has resulted in improved recovery (compared to a pure water injection) for almost all of the field cases reviewed in this work. Although mobility control is an important issue, other advantages of the WAG injection should be noticed as well. Compositional exchanges may give some additional recovery and may influence the fluid densities and viscosities. Reinjection of gas is favorable owing to environmental concerns, enforced restrictions on flaring, and - in some areas - CO2 taxes. The WAG injection results in a complex saturation pattern because two saturations (gas and water) will increase and decrease alternately. This gives special demands for the relative permeability description for the three phases (oil, gas, and water). There are several correlations for calculating three-phase relative permeability in the literature,95 but only recently has an approach been designed for WAG injection using cycle-dependent relative permeability.95 WAG injection has been applied with success in most field trials. The majority of the fields are located in Canada and the U.S., but there are also some fields in the former USSR. WAG injection has been applied since the early 1960's. Both miscible and immiscible injections have been applied, and many different types of gas have been used. This work gives a review of the WAG injection as it is found in the open literature today. Unfortunately, not all field trials are adequately described, and this overview is limited to the publicly accessible data. We have chosen to use an inclusive definition of WAG injection that covers all cases where both gas and water are injected in the same well. A process where one gas slug is followed by a water slug is, by definition, considered a WAG process. In the literature, WAG injection processes are also referred to as combined water/gas injection (CGW).100 Classification of the WAG Process. WAG processes can be grouped in many ways. The most common is to distinguish between miscible and immiscible displacements as a first classification. Miscible WAG Injection. It is difficult to distinguish between miscible and immiscible WAG injections. In many cases a multicontact gas/oil miscibility may have been obtained, but much uncertainty remains about the actual displacement process. In this paper, we have used only the information from the literature and find that most cases have been defined as miscible. It has not been possible to isolate the degree of compositional effect on oil recovery by WAG injection. Miscible projects are mostly found onshore, and the early cases used expensive solvents like propane, which seem to be a less economically favorable process at present. Most of the miscible projects reviewed are repressurized in order to bring the reservoir pressure above the minimum miscibility pressure (MMP) of the fluids. Because of failure to maintain sufficient pressure, meaning loss of miscibility, real field cases may oscillate between miscible and immiscible gas during the life of the oil production. Most miscible WAG injections have been performed on a close well spacing, but recently miscible processes have also been attempted even at offshore-type well spacing.86–90 Immiscible WAG Injection. This type of WAG process has been applied with the aim of improving frontal stability or contacting unswept zones. Applications have been in reservoirs where gravity-stable gas injection cannot be applied because of limited gas resources or reservoir properties like low dip or strong heterogeneity. In addition to sweep, the microscopic displacement efficiency may be improved. Residual oil saturations are generally lower for WAG injection than for a waterflood and sometimes even lower than a gasflood, owing to the effect of three-phase and cycle-dependent relative permeability.96,97 Sometimes the first gas slug dissolves to some degree into the oil. This can cause mass exchange (swelling and stripping) and a favorable change in the fluid viscosity/density relations at the displacement front. The displacement can then become near-miscible. Hybrid WAG Injection. When a large slug of gas is injected, followed by a number of small slugs of water and gas, the process is referred to as hybrid WAG injection.38–42 Others. A process where water and gas are injected simultaneously (SWAG injection) has been tested in a few reservoirs.37,106–108 Although this process is not the main scope of the paper, a few comments are given at the end. A final version of the cyclic injection is in the literature presented as Water Alternating Steam Process (WASP).102 Reviews of field cases will not be included in this paper.
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Budak, Paweł, and Tadeusz Szpunar. "Ocena możliwości zrzutu zasolonych wód poeksploatacyjnych do wyeksploatowanych odwiertów." Nafta-Gaz 77, no. 11 (November 2021): 752–59. http://dx.doi.org/10.18668/ng.2021.11.05.
Повний текст джерелаАнотація:
W artykule omówiono zagadnienia zrzutu zasolonych wód poeksploatacyjnych do porowatych warstw chłonnych o niskim ciśnieniu złożowym – z zastosowaniem pompy lub bez niej. Podano warunki, jakie musi spełniać warstwa chłonna, oraz klasyfikację odwiertów zrzutowych według amerykańskiej Agencji Ochrony Środowiska (EPA) ze względu na ochronę wód pitnych. Zasygnalizowano, jakie warunki musi spełniać solanka wprowadzana do ośrodka porowatego, w tym dotyczące jej składu chemicznego, zawartości ciał stałych, obecności bakterii oraz zawartości olejów i tłuszczów. Podano sposoby określenia przepuszczalności warstwy o niskim ciśnieniu złożowym, z której brak jest samoczynnego wypływu i lustro cieczy stabilizuje się na pewnej głębokości poniżej poziomu terenu, w tym omówiono metodę tzw. slug test oraz metodę INiG – PIB opracowaną przez autorów. Podano warunki techniczne, których spełnienie wymagane jest do prawidłowego przeprowadzenia slug testu. Omówiono wady i zalety poszczególnych metod określania przepuszczalności w odwiertach, w których nie ma produkcji samoczynnej, oraz sposoby interpretacji wyników, jak również podkreślono prostotę interpretacji metodą INiG – PIB w porównaniu z metodą slug testu, wymagającą wpasowania krzywych pomiarowych do krzywych teoretycznych. Podano sposób przybliżonej oceny objętości wody zasolonej, którą można wprowadzić do otworu „na chłonność”, to jest bez użycia pompy, przy maksymalnym ciśnieniu hydrostatycznym odpowiadającym wypełnieniu otworu solanką „do wierzchu”, oraz objętości, którą można wtłoczyć za pomocą pompy przy ciśnieniu niższym od ciśnienia szczelinowania warstwy porowatej. Podano przykład obliczeniowy.
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Tan, Li, and Parwinder S. Grewal. "Characterization of the First Molluscicidal Lipopolysaccharide from Moraxella osloensis." Applied and Environmental Microbiology 69, no. 6 (June 2003): 3646–49. http://dx.doi.org/10.1128/aem.69.6.3646-3649.2003.
Повний текст джерелаАнотація:
ABSTRACT Moraxella osloensis is a bacterium that is mutualistically associated with Phasmarhabditis hermaphrodita, a nematode that has potential for the biocontrol of mollusk pests, especially the slug Deroceras reticulatum. We discovered that purified M. osloensis lipopolysaccharide (LPS) possesses a lethal toxicity to D. reticulatum when administered by injection but no contact or oral toxicity to this slug. The toxicity of the LPS resides in the lipid A moiety. M. osloensis LPS was semiquantitated at 6 � 107 endotoxin units per mg. The LPS is a rough-type LPS with an estimated molecular weight of 5,300. Coinjection of galactosamine with the LPS increased the LPS's toxicity to the slug two- to four-fold. The galactosamine-induced sensitization of the slug to the LPS was reversed completely by uridine.
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Abdel-Mageed, Neveen B., Ashraf Ghanem, Ibrahim G. Shaaban, Atiyeh Ardakanian, Mohamed M. M. Ibrahem, and Mohamed Elgamal. "Effect of Using a Passive Rotor on the Accuracy of Flow Measurements in Sewer Pipes Using a Slug Tracer-Dilution Method." Water 15, no. 2 (January 16, 2023): 369. http://dx.doi.org/10.3390/w15020369.
Повний текст джерелаАнотація:
Flow measurements in pipelines using slug tracer have proved highly accurate for turbulent flow. This study experimentally investigates the effectiveness of using a passive rotor on the accuracy of discharge measurements in sewer pipes based on a saline slug tracer technique. For this purpose, a saline injector stack was developed to help inject saline at selected injection points. A passive axial flow rotor was also proposed and encased in the injector stack to enhance the mixing of injected tracer with the transmitted downstream flow and to decrease the required minimum mixing length. It was found that adding the passive rotor significantly increased the accuracy of the flow measurements. Two tracer flow formulas were developed: one based on the dimensional analysis approach and the other based on a semi-empirical formula obtained from the mass conservation approach. The resultant formulas compared favourably with flow metering, especially when utilizing the passive fan unit.
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Boeije, C. S. S., and W. R. R. Rossen. "Gas-Injection Rate Needed for SAG Foam Processes To Overcome Gravity Override." SPE Journal 20, no. 01 (May 23, 2014): 49–59. http://dx.doi.org/10.2118/166244-pa.
Повний текст джерелаАнотація:
Summary Gravity override is a severe problem in gas-injection enhanced-oil-recovery (EOR) processes, especially in relatively homogeneous formations. Foam can reduce gravity override. Shan and Rossen (2004) show that the best foam process for overcoming gravity override is one of injecting a large slug of surfactant followed by a large slug of gas, injected at constant, maximum-allowable injection pressure. This process works because foam collapses near the injection well, giving good injectivity simultaneously with mobility control at the leading edge of the gas bank. The supply of gas that would be needed to maintain constant injection pressure is a concern for EOR processes in which gas is produced industrially or from a separations plant with limited capacity: The available gas stream may not be sufficient for the optimal process. We show that for such a process, the pressure drop across the foam bank back to the injection well, at fixed injection rate, is nearly constant as the foam bank propagates radially outward. From this result, one can derive a simple formula to predict the rate of gas injection required for each of two limiting cases: An extremely strong foam at the foam front, many times more viscous than the fluids it displaces. In this case, the rate of gas injection required to maintain constant injection pressure is nearly constant, but injection rate is low. A foam just strong enough to maintain mobility control at its leading edge. In this case, injection rate required to maintain constant injection pressure increases steeply with time. Use of the formulae provides a quick initial estimate of how gas-injection rate must vary over the duration of the EOR process to maintain an optimal process. The fit to simulations of surfactant-alternating-gas (SAG) foam-injection rate in a five-spot pattern is remarkably good, especially for strong foam, given the simplicity of the model. In addition, we illustrate how one would determine the properties of a foam that would fit the available gas stream. This criterion then could guide the development of a surfactant formulation with these properties.
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Kozhash, A. S. "Analysis of the steam-thermal treatment at the Karazhanbas field." Kazakhstan journal for oil & gas industry 3, no. 4 (December 15, 2021): 52–62. http://dx.doi.org/10.54859/kjogi99698.
Повний текст джерелаАнотація:
The article describes the main features of the geological structure of the Jurassic-Cretaceous productive strata of the Karazhanbas field, located on the Buzachi Peninsula (Western Kazakhstan), and the effectiveness of thermal methods and their modifications to enhance oil recovery, which have been used in the field since the 80s of the last century. The use of thermal steam stimulation in the form of thermal slugs allows not only to cover most of the formation with thermal steam stimulation by switching to unheated water injection in a number of wells and transferring steam injection to other wells, but also to intensify the movement of the thermal slug in the formation during the cold water injection process. As a result, the steam-oil ratio when using thermal rims and increasing the steam injection rate can be several times less than with continuous slow steam injection. The use of thermal steam treatment allows increasing oil recovery by 3545% of the initial balance oil reserves. Testing and implementation of new equipment and technology, as well as the study of world experience in the development of high-viscosity oil are currently relevant for the development of the Karazhanbas field.
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Li, Xiang, Yuan Cheng, Wulong Tao, Shalake Sarulicaoketi, Xuhui Ji, and Changhe Yin. "Experimental Study on Enhanced Oil Recovery by Nitrogen-Water Alternative Injection in Reservoir with Natural Fractures." Geofluids 2021 (September 23, 2021): 1–9. http://dx.doi.org/10.1155/2021/6653399.
Повний текст джерелаАнотація:
The production of a low permeability reservoir decreases rapidly by depletion development, and it needs to supplement formation energy to obtain stable production. Common energy supplement methods include water injection and gas injection. Nitrogen injection is an economic and effective development method for specific reservoir types. In order to study the feasibility and reasonable injection parameters of nitrogen injection development of fractured reservoir, this paper uses long cores to carry out displacement experiment. Firstly, the effects of water injection and nitrogen injection development of a fractured reservoir are compared through experiments to demonstrate the feasibility of nitrogen injection development of the fractured reservoir. Secondly, the effects of gas-water alternate displacement after water drive and gas-water alternate displacement after gas drive are compared through experiments to study the situation of water injection or gas injection development. Finally, the reasonable parameters of nitrogen gas-water alternate injection are optimized by orthogonal experimental design. Results show that nitrogen injection can effectively enhance oil production of the reservoir with natural fractures in early periods, but gas channeling easily occurs in continuous nitrogen flooding. After water flooding, gas-water alternate flooding can effectively reduce the injection pressure and improve the reservoir recovery, but the time of gas-water alternate injection cannot be too late. It is revealed that the factors influencing the nitrogen-water alternative effect are sorted from large to small as follows: cycle injected volume, nitrogen and water slug ratio, and injection rate. The optimal cycle injected volume is around 1 PV, the nitrogen and water slug ratio is between 1 and 2, and the injection rate is between 0.1 and 0.2 mL/min.
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Pecly, J. O. G., and J. S. F. Roldão. "Dye tracers as a tool for outfall studies: dilution measurement approach." Water Science and Technology 67, no. 7 (April 1, 2013): 1564–73. http://dx.doi.org/10.2166/wst.2013.027.
Повний текст джерелаАнотація:
Dye tracer technique is well established and of wide application for assessment of outfalls and for delineation of near field and far field extensions. Common goals of a tracer study include the measurement of the dilution factor, estimation of the dispersion coefficients, measurement of the effluent discharge and calibration of a contaminant transport model. This paper presents a brief review of the methods involving the use of dye tracer for outfall assessment and illustrates the methods of slug release and continuous injection based on two real cases of campaigns carried out on Brazilian coastal waters. Slug injection on the surface of the water body was used for preliminary dispersion studies aiming at outfall positioning. During the operational phase of an outfall, the continuous injection of dye tracer was used to determine effluent dilution in different seasons. In coastal waters of Rio de Janeiro city, sea current pattern, tidal modulation and thermal stratification explained the main features of the dilution field.
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Jones, Stanley C. "Some Surprises in the Transport of Miscible Fluids in the Presence of a Second Immiscible Phase." Society of Petroleum Engineers Journal 25, no. 01 (February 1, 1985): 101–12. http://dx.doi.org/10.2118/12125-pa.
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Jones, Stanley C., SPE, Marathon Oil Co. Abstract Displacements were conducted in Berea cores to gain insight into the mechanism of tertiary oil displacement and propagation by a micellar slug. Contrary to expectation, propagation by a micellar slug. Contrary to expectation, the first oil mobilized by micellar fluid was among the first oil (instead of the last oil) to be produced, giving the appearance of either viscous fingering or of unusually large dispersion. To eliminate the possibility of unfavorable mobility ratios caused by oil/water/surfactant interaction, we conducted several runs in which an injected hydrocarbon displaced another hydrocarbon, initially at residual saturation. In other experiments, water (the wetting phase) at irreducible saturation was displaced by a distinguishable injected aqueous phase. Injected hydrocarbon appeared in the produced fluids immediately after oil breakthrough, yielding behavior similar to the micellar-slug experiments. Even with a favorable viscosity ratio of less than 0.01, the apparent dispersion was huge. However, mixing zones in the wetting-phase displacements were quite normal and similar to those observed for single-phase flow. Nonwetting-phase fronts (injected hydrocarbon displacing resident hydrocarbon) are smeared much more than wetting-phase fronts because the entrance of hydrocarbon into smaller water-filled pore throats is delayed until the capillary entrance pressure is overcome by differences in the flowing oil and water pressure gradients. Oil might not be displaced from the smaller pores until long after oil breakthrough. Nonwetting-phase dispersion, which occurs in many EOR processes, can be expected to be one or two orders of magnitude greater than dispersion measured in single-phase-flow experiments. Entrance of the wetting phase, however, is not delayed; hence, wetting-phase Mixing zones are short. Introduction Experiments for this study were inspired by the question: How is residual oil, which has been mobilized by a micellar slug, transported? More specifically, does the first oil mobilized by a slug (near the injection end of a core) contact and mobilize oil downstream from it, which displaces more oil even farther downstream? If this were the case, the first oil to be produced would be the most-downstream oil (i.e., oil nearest the outlet). The last oil produced would be the first oil mobilized from the produced would be the first oil mobilized from the injection end of the core. This scheme is somewhat analogous to pushing a broom across a floor covered with a heavy layer of dust. The first dust encountered by the broom stays next to the broom. As the accumulated layer of dust in front of the broom becomes adequately compacted, it pushes dust ahead of it to from an ever-widening band or "dust bank" ahead of the broom. The dust farthest ahead of the broom is the first to be pushed into the dustpan, and the dust first encountered by the broom is the last to be pushed in. Or is this concept all wrong? Another model postulates that the oil first contacted by a micellar slug is mobilized and quickly travels away from the slug so that the downstream oil is contacted and mobilized by the slug, not by the first-mobilized oil. If this process were to proceed to its logical conclusion, the first-produced oil would proceed to its logical conclusion, the first-produced oil would be from the inlet end of the core, and the last-produced from the outlet end. Either of these two extremes would be modified by dispersion, which smears sharp fronts by mixing displaced and displacing fluids. Dispersion in porous media has been investigated extensively. Perkins and Johnston have reviewed several studies, mostly involving single-phase flow. The simultaneous injection of the water with light hydrocarbon solvents is a technique used to reduce solvent mobility and viscous fingering. Raimondi et al. performed steady-state experiments in which flowing performed steady-state experiments in which flowing water and oil were miscibly displaced by the simultaneous injection of water and solvent. They found that the longitudinal mixing coefficient for the hydrocarbon phase increased sharply with increasing water above the irreducible saturation. The displacement of the wetting phase was not greatly affected by the presence of the nonwetting phase. However, a large amount of oil that initially phase. However, a large amount of oil that initially seemed to be trapped by water was eventually recovered by continued solvent injection. Raimondi and Torcaso later found that some oil, particularly at high water-to-solvent injection ratios, was particularly at high water-to-solvent injection ratios, was trapped permanently, provided that injection rates, ratios, and pressure drops were unchanged in switching from water/oil to water/solvent injection. Fitzgerald and Nielsen also found that only part of the in-place crude was recovered by solvent injection. Moreover, solvent appeared in the effluent shortly after oil breakthrough. Oil recovery was further decreased when solvent and water were injected simultaneously. Thomas et al. reported slightly increased wetting-phase longitudinal mixing during simultaneous water/oil injection as the wetting-phase saturation decreased. Non-wetting-phase mixing increased substantially as the nonwetting-phase saturation decreased from 100%. SPEJ p. 101
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Zheng, Wei, Tingen Fan, Xianhong Tan, Weidong Jiang, Taichao Wang, and Haojun Xie. "Numerical Simulations of Chemical-Assisted Steam Flooding in Offshore Heavy Oil Reservoirs after Water Flooding." Geofluids 2021 (July 24, 2021): 1–10. http://dx.doi.org/10.1155/2021/8794022.
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Chemical-assisted steam flooding (CASF) is a promising method for heavy oils. However, few researches have investigated the CASF performance on offshore heavy oil reservoirs recovery after water flooding. In this study, a numerical simulation model was developed to simulate CASF processes for offshore heavy oil reservoirs after water flooding. Then, a comparison of CASF and various thermal methods was made to assess the feasibility of CASF in an offshore heavy reservoir of Bohai Bay, China. Finally, sensitivity analysis was performed to evaluate the effects of the gas-liquid ratio, foaming agent concentration, surfactant concentration, the size of nitrogen foam slug, the size of surfactant slug, and the number of chemical injection round on CASF performance by the developed model. The results showed that the developed numerical method can precisely simulate the CASF processes. CASF is a potential and effective method for offshore heavy oil reservoirs after water flooding. The most suitable gas-liquid ratio was around 2 : 1 under the simulation conditions. Considering the economic benefit, it is significant to optimize the CASF parameters, such as foaming agent concentration, the size of nitrogen foam slug, and the number of chemical injection round.
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Tunnish, Ahmed, Ezeddin Shirif, and Amr Henni. "Alkaline‐ionic liquid slug injection for improved heavy oil recovery." Canadian Journal of Chemical Engineering 97, S1 (February 16, 2019): 1429–39. http://dx.doi.org/10.1002/cjce.23431.
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Nowrouzi, Iman, Amir H. Mohammadi, and Abbas Khaksar Manshad. "Preliminary evaluation of a natural surfactant extracted from Myrtus communis plant for enhancing oil recovery from carbonate oil reservoirs." Journal of Petroleum Exploration and Production Technology 12, no. 3 (October 21, 2021): 783–92. http://dx.doi.org/10.1007/s13202-021-01336-6.
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AbstractSurfactants are among the materials used to improve water properties for injection into oil reservoirs, and reduce injection phase and crude oil interfacial tension (IFT). Recently, the interest in the use of natural surfactants has increased and is constantly on the rise to solve some challenges of using chemical surfactants such as incompatibility with the environment and the high cost. In this study, we have used aqueous extract of powdered leaf of Myrtus communis as an available source of natural surfactant. The extracted surfactant was characterized by TGA, 1H NMR and FTIR techniques. The surfactant efficiency was demonstrated by performing some experiments including IFT and injection of chemical slug and surfactant into carbonate plugs. The surfactant adsorption on carbonate rock was also studied. It was observed that this natural surfactant can reduce IFT to 0.861 mN/m at surfactant critical micelle concentration (CMC) of 5000 ppm. This minimum IFT was further reduced at optimum salinity and alkali. Finally, an increase of 14.3% oil recovery by surfactant flooding and 16.4% oil recovery by ASP slug injection containing NaOH alkali and partially hydrolyzed polyacrylamide (PHPA) polymer with 0.5 PV volume from carbonate plugs was achieved.
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Sun, Lili, Xining Hao, Hongen Dou, Caspar Daniel Adenutsi, Zhiping Li, and Yunjun Zhang. "Co-optimization of oil recovery and CO2 storage for cyclic CO2 flooding in ultralow permeability reservoirs." Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73 (2018): 42. http://dx.doi.org/10.2516/ogst/2018041.
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Cyclic CO2 flooding is an efficient method to enhance oil recovery in ultralow permeability reservoirs. As the demand for low carbon economy development, co-optimization of CO2 storage and utilization should be considered. In this research, initially a comprehensive optimization method was proposed, which co-optimize oil recovery and CO2 storage by different weighting factors. Then, a series of core flooding experiments were performed using the core samples collected from Changqing oilfield, which is a ultralow permeability reservoir with heterogeneity and micro-cracks, CO2 injection parameters of slug size and Injection-Soaking Time Ratio (ISR) were optimized. The results revealed that the optimal injection parameters changed for different optimization objectives. In the case where equal important to oil recovery and CO2 storage were considered, the optimum CO2 injection parameters in the ultralow permeability reservoirs were 0.03PV for slug size and 1:1 for ISR. Comparing the method of oil recovery optimization (ω 1 = 1) to co-optimization of oil recovery and CO2 storage (ω 1 = ω 2 = 0.5), oil recovery was reduced by 8.93%, CO2 storage was significantly increased by 25.85%. The results provide an insight into parameter optimization of CO2 enhanced oil recovery design.
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Gao, J., D. Jiang, Z. Huang, and X. Wang. "Experimental and numerical study of high-pressure-swirl injector sprays in a direct injection gasoline engine." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 219, no. 8 (December 1, 2005): 617–29. http://dx.doi.org/10.1243/095765005x31333.
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The characteristics of free spray of a new type high-pressure-swirl injector in gasoline direct injection (GDI) engine under various injection conditions are investigated. The fuel spray with hollow-cone structure, wide spreading, and large spray angle is observed under the injection condition simulating to the GDI engine operation at full load. The study shows that a vortex structure can be clearly observed in the periphery of the spray. Meanwhile, an initial spray slug also appears at the tip of the main spray. Under the injection condition of GDI engine partial load, the structure of fuel spray changes into the more compact and solid-cone shape with decreased spray width. Moreover, the influences of the injection pressures and ambient pressures on the spray characteristics of the injector are studied. Along with the experimental studies, a general numerical model for the swirl spray is developed. Then, the model is implemented into a multi-dimensional computational fluid dynamics code (KIVA-3V) to theoretically study the pressure-swirl injector sprays. Comparisons between the computed and measured spray characteristics such as spray structure, spray tip penetration, and droplet sizes are made, and good agreement has been achieved between the model prediction and measurement.
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Dietzel, Hans Joachim, and Gunter Pusch. "Laboratory Investigations of the Dynamic Stability of Polymer Slugs." Society of Petroleum Engineers Journal 25, no. 01 (February 1, 1985): 9–13. http://dx.doi.org/10.2118/10614-pa.
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Abstract To assess the dynamic stability of polymer slugs, flooding experiments have been performed in sandpacks and consolidated sandstone cores. The investigations have been carried out with a hydroxyethylcellulose (HEC) and a biopolysaccharide (BPS) (scleroglucane). Highly saline water (100 g/dm3 [0.2 lbm/L]) was used for the displacement tests, as well as for the preparation of the polymer solutions. preparation of the polymer solutions. From the eluate sampled during each flooding test, a concentration profile and a viscosity profile were recorded. A comparison between the two profiles gives an indication of the fraction of the polymer substance in the injected solution that does not contribute to the viscosity. From the recorded profiles, the influences of dispersion, adsorption/retention, and viscous fingering were established separately and quantitatively determined by means of material balances. Introduction In EOR, polymer slugs are used both for mobility control in the micellar/polymer process and for viscous flooding. To yield maximum success in polymer flooding - from a laboratory experimental, and not an economic, point of view - it is necessary that the mobility control effected by the polymer slug be maintained all the way from the injection well to the production wells. During its passage through the porous medium, the shape of the polymer slug, as indicated by the concentration profile, is altered and impaired as a result of interactions with the mobile phases and the rock matrix. phases and the rock matrix. In this paper, flooding experiments in linear models of porous media are described; the objective is to investigate the porous media are described; the objective is to investigate the stability of polymer slugs under dynamic conditions. The influence of the interactions that alter the slug has been determined separately and quantitatively established from these experiments. The fraction and distribution of the polymer substance in the injected solution that does not contribute to the viscosity is indicated too. Theory The action of a polymer slug is based on the adjustment of the mobility between the displaced phase and the displacing floodwater, 1 Hence, two transition zones characterize the mechanism of slug flooding:the transition from the displaced phase to the polymer slug andthe transition from the polymer slug to the polymer slug andthe transition from the polymer slug to the displacing floodwater. If the mobility ratio at the leading edge of the slug is decreased to values near unity by the polymer solution, the effect of viscous fingering is suppressed, and the displacement is piston-like. At the trailing edge of the slug, on the contrary, an unfavorable viscosity ratio prevails; consequently, floodwater penetrates into the slug as a result of viscous fingering. In addition to these purely dynamic effects, the interaction between the rock matrix and polymer solution also causes an alteration of the slug during the passage through the porous medium. This change is described in terms of longitudinal dispersion and adsorption/retention. The term "longitudinal dispersion" designates the effect of microscopic inhomogeneities in the porous medium; this effect leads to a broadening of the mixing zone between the miscible fluids beyond that caused by molecular diffusion. "Adsorption" is defined here according to the Langmuir isotherm, whereas "retention" also includes the effects of filtration and time dependence of the adsorption equilibrium. The alteration of the polymer slug during passage through a porous model can be described polymer slug during passage through a porous model can be described by means of a comparison between the concentration profile of the slug emerging from the porous medium and that of the injected slug. Since the rheological properties of the mobile phases are also of importance for appraising the transport phenomena in the pore space, it is expedient to consider the viscosity profiles in pore space, it is expedient to consider the viscosity profiles in addition to the concentration profiles. Fig. 1 shows the originally injected rectangular profile (dashed line) and the concentration or viscosity profile obtained from the eluate of the flood test. The deviation of the leading edge of the profile from the rectangular shape is characterized by two parameters:the displacement of the 50% value by an amount "d"; andthe inclination of the profile line by an angle,. The amount "d" is thereby a measure of the denudation of the leading zone by adsorption and retention, whereas the angle of inclination, is proportional to the influence of dispersion. The area denoted by "A/R, "the surface area corresponding to adsorption/retention, between the rectangular profile and the measured or extrapolated profile line is a measure of the polymer loss resulting from adsorption and retention. The effect of viscous fingering on the trailing edge is described in terms of the shift of the water breakthrough, "WD," from 1.0 PV after the start of waterflooding to lower values. The polymer initially delayed by viscous fingering is produced subsequently at lower concentration in the trailing edge but does not contribute to the viscosity of the displacing part of the slug. SPEJ P. 9
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Brown, Gary E., Debra A. Davenport, and Angela R. Howe. "Naloxone Blocks Learned Helplessness in the Slug (Limax Maximus)." Psychological Reports 76, no. 1 (February 1995): 14. http://dx.doi.org/10.2466/pr0.1995.76.1.14.
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Zhang, Tiantian, Michael J. Murphy, Haiyang Yu, Hitesh G. Bagaria, Ki Youl Yoon, Bethany M. Neilson, Christopher W. Bielawski, Keith P. Johnston, Chun Huh, and Steven L. Bryant. "Investigation of Nanoparticle Adsorption During Transport in Porous Media." SPE Journal 20, no. 04 (August 20, 2015): 667–77. http://dx.doi.org/10.2118/166346-pa.
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Summary Nanoparticles (diameter of approximately 5 to 50 nm) easily pass through typical pore throats in reservoirs, but physicochemical attraction between nanoparticles and pore walls may still lead to significant retention. We conducted an extensive series of nanoparticle-transport experiments in core plugs and in columns packed with crushed sedimentary rock, systematically varying flow rate, type of nanoparticle, injection-dispersion concentration, and porous-medium properties. Effluent-nanoparticle-concentration histories were measured with fine resolution in time, enabling the evaluation of nanoparticle adsorption in the columns during slug injection and post-flushes. We also applied this analysis to nanoparticle-transport experiments reported in the literature. Our analysis suggests that nanoparticles undergo both reversible and irreversible adsorption. Effluent-nanoparticle concentration reaches the injection concentration during slug injection, indicating the existence of an adsorption capacity. Experiments with a variety of nanoparticles and porous media yield a wide range of adsorption capacities (from 10–5 to 101 mg/g for nanoparticles and rock, respectively) and also a wide range of proportions of reversible and irreversible adsorption. Reversible- and irreversible-adsorption sites are distinct and interact with nanoparticles independently. The adsorption capacities are typically much smaller than monolayer coverage. Their values depend not only on the type of nanoparticle and porous media, but also on the operating conditions, such as injection concentration and flow rate.
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Zhan, Jie, Chao Fan, Xianlin Ma, Zigang Zheng, Zezhong Su, and Zhihao Niu. "High-Precision Numerical Simulation on the Cyclic High-Pressure Water Slug Injection in a Low-Permeability Reservoir." Geofluids 2021 (July 30, 2021): 1–10. http://dx.doi.org/10.1155/2021/3507426.
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The paper presents a novel waterflooding technique, coupling cyclic high-pressure water slug injection with an asynchronous injection and production procedure, to address the inefficient development of low-permeability oil reservoir in Shengli Oilfield, a pilot test with 5-spot well pattern. Based on the first-hand data from the pilot test, the reservoir model is established. With an in-depth understanding of the mechanism of the novel waterflooding technique, different simulation schemes are employed to screen the best scheme to finely investigate the historical performance of the pilot test. The production characteristics of the pilot test are both qualitatively and quantitatively investigated. It is found that the novel waterflooding technique can provide pressure support within a short period. And the formation around the injector is significantly activated and deformed. Once passing the short stage of the small elastic deformation, the reservoir immediately goes through the dilation deformation accompanied with the opening of microfractures so that the reservoir properties are significantly improved, which leads to better reservoir performance. With the multicyclic dilation-recompaction geomechanical model, the impact of pressure cyclic evolution on the reservoir properties and performance under the novel waterflooding mode of cyclic high-pressure water slug injection is taken into consideration. The historical data of the pilot test is well matched. In the study, a high-precision simulation scheme for the novel waterflooding technique in low-permeability reservoirs is proposed, which provides significant technical support for further optimization of the pilot test and large-scale application of the novel waterflooding technique.
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Zhao, Yanrong, Xiaosong Dong, Haonan Wang, Jinguo Wang, Yufeng Wei, Yong Huang, and Ruifeng Xue. "Comparative Study on the Application of Different Slug Test Models for Determining the Permeability Coefficients of Rock Mass in Long-Distance Deep Buried Tunnel Projects." Applied Sciences 12, no. 20 (October 11, 2022): 10235. http://dx.doi.org/10.3390/app122010235.
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In large-scale water diversion projects, especially in the central and western regions of China, long-distance deep buried tunnels are generally involved. Therefore, it is essential to carry out field tests to obtain the permeability of the rock mass through which tunnels pass. However, the test holes of large-scale water diversion projects are basically located in mountain areas with complex hydrogeological conditions. Meanwhile, the test holes are far apart and large in depth. As a result, traditional pumping tests cannot meet the requirements. Therefore, the slug test was chosen as the main test method, and the calculation results of the water injection test, the water pressure test and the slug test are analyzed and compared. The calculation results of the three test methods are basically consistent. However, the water injection test and the water pressure test are difficult to implement at a large scale due to many environmental constraints, complex test equipment, long test periods and other factors. Furthermore, the Kipp model, the CBP model and the proposed HWS model, considering the effect of the finite thickness well-skin layer for the first time, were used to analyze and process the slug test data, respectively. The curve fitting effect of the Kipp model was the best, but the calculations were generally larger. The difference between the CBP model and the proposed HWS model is smaller in the calculation results; however, the curve fitting effect of the CBP model is the worst, and the CBP model needs to be further improved. The curve fitting effect of the proposed HWS model was between that of the Kipp model and the CBP model, and the proposed HWS model can be applied to the parameter calculations of the slug test with well-skin. In general, with reference to the criteria for the damping coefficient of the aquifer in the Kipp model, the Kipp model was applicable to the slug test for test holes without well-skin and an aquifer damping coefficient between 0.1 and 5.0. The CBP model was applicable to the slug test under the conditions of no well-skin and an aquifer damping coefficient greater than 2.0. The novel proposed HWS model was applicable to the slug test when the aquifer damping coefficient was greater than 1.0 under the conditions of no well-skin, positive well-skin and negative well-skin.
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Bandeira, Francisco J. S., Gabriel F. N. Gonçalves, Juliana B. R. Loureiro, and Atila P. Silva Freire. "Turbulence and Bubble Break up in Slug Flow with Wall Injection." Flow, Turbulence and Combustion 98, no. 3 (October 28, 2016): 923–45. http://dx.doi.org/10.1007/s10494-016-9786-6.
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Hu, Gang, Pengchun Li, Linzi Yi, Zhongxian Zhao, Xuanhua Tian, and Xi Liang. "Simulation of Immiscible Water-Alternating-CO2 Flooding in the Liuhua Oilfield Offshore Guangdong, China." Energies 13, no. 9 (April 28, 2020): 2130. http://dx.doi.org/10.3390/en13092130.
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In this paper, the immiscible water-alternating-CO2 flooding process at the LH11-1 oilfield, offshore Guangdong Province, was firstly evaluated using full-field reservoir simulation models. Based on a 3D geological model and oil production history, 16 scenarios of water-alternating-CO2 injection operations with different water alternating gas (WAG) ratios and slug sizes, as well as continuous CO2 injection (Con-CO2) and primary depletion production (No-CO2) scenarios, have been simulated spanning 20 years. The results represent a significant improvement in oil recovery by CO2 WAG over both Con-CO2 and No-CO2 scenarios. The WAG ratio and slug size of water affect the efficiency of oil recovery and CO2 injection. The optimum operations are those with WAG ratios lower than 1:2, which have the higher ultimate oil recovery factor of 24%. Although WAG reduced the CO2 injection volume, the CO2 storage efficiency is still high, more than 84% of the injected CO2 was sequestered in the reservoir. Results indicate that the immiscible water-alternating-CO2 processes can be optimized to improve significantly the performance of pressure maintenance and oil recovery in offshore reef heavy-oil reservoirs significantly. The simulation results suggest that the LH11-1 field is a good candidate site for immiscible CO2 enhanced oil recovery and storage for the Guangdong carbon capture, utilization and storage (GDCCUS) project.
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Rahmani, Amir Reza, Steve Bryant, Chun Huh, Alex Athey, Mohsen Ahmadian, Jiuping Chen, and Michael Wilt. "Crosswell Magnetic Sensing of Superparamagnetic Nanoparticles for Subsurface Applications." SPE Journal 20, no. 05 (October 20, 2015): 1067–82. http://dx.doi.org/10.2118/166140-pa.
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Summary Stable dispersions of superparamagnetic nanoparticles that are already in use in biomedicine as image-enhancing agents also have potential use in subsurface applications. Surface-coated nanoparticles are capable of flowing through micron-sized pores across long distances in a reservoir, with modest retention in rock. These particles change the magnetic permeability of the flooded region, and thus one can use them to enhance images of the flood. In this paper, we model the propagation of a “ferrofluid” slug in a reservoir and its response to a crosswell magnetic tomography system. This approach to monitoring fluid movement within a reservoir is built on established electromagnetic (EM) conductivity-monitoring technology. In this work, however, we investigate the contrast between injected and resident fluids when they have different magnetic permeabilities. Specifically, we highlight the magnetic response at low frequency to the magnetic excitations generated by a vertical magnetic dipole source positioned at the injection well. At these frequencies, the induction effect is small, the casing effect is manageable, the crosswell response originates purely from the magnetic contrast in the formation, and changes in fluid conductivities are irrelevant. The sensitivity of the measurements to the magnetic slug is highest when the slug is closest to the source or receivers and lower when the slug is midway in the interwell region. At low frequencies, the magnetic response of the ferrofluid slug is largely independent of frequency. As expected for the conductive slug, the sensitivity of the inductive measurements is negligible at low frequencies whereas significant levels of detectability result at higher frequencies. We demonstrate sensitivity to the vertical boundaries of the slug by shifting the vertical position of the excitation source relative to the magnetic slug. The slug geometry plays a key role in determining the magnetic response. With a fixed volume of ferrofluid, there is an optimum slug geometry that results in the maximum magnetic response. Hydrodynamic dispersion of the slug has negligible effect on the magnetic response during early stages of the waterflood. As the slug travels farther into the formation, however, dispersion reduces the concentration of nanoparticles, and the spatial contributions of the magnetic measurements are more diffuse. We illustrate how these low-frequency excitation behaviors are consistent with the quasistatic magnetic dipole physics. The fact that the progress of the magnetic slug can be detected at very early stages of the flood, that the traveling slug's vertical boundaries can be identified at low frequencies, and that the magnetic nanoparticles can be sensed well before the actual arrival of the slug at the observer well provide significant value of the use of the magnetic-contrast agents in crosswell EM tomography.
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Kim, Jong-Hwan, Ki-Hwan Kim, and Chan-Bock Lee. "Preparation of U–Zr–Mn, a Surrogate Alloy for Recycling Fast Reactor Fuel." Advances in Materials Science and Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/131704.
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Metallic fuel slugs of U–10Zr–5Mn (wt%), a surrogate alloy for the U–TRU–Zr (TRU: a transuranic element) alloys proposed for sodium-cooled fast reactors, were prepared by injection casting in a laboratory-scale furnace, and their characteristics were evaluated. As-cast U–Zr–Mn fuel rods were generally sound, without cracks or thin sections. Approximately 68% of the original Mn content was lost under dynamic vacuum and the resulting slug was denser than those prepared under Ar pressure. The concentration of volatile Mn was as per the target composition along the entire length of the rods prepared under 400 and 600 Torr. Impurities, namely, oxygen, carbon, silicon, and nitrogen, totaled less than 2,000 ppm, satisfying fuel criteria.