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Статті в журналах з теми "GLM cleaning"
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LEE, YONG-JOONG, and CLAUS-DIETER MUNZ. "ADVANCED HYPERBOLIC DIVERGENCE CLEANING SCHEME FOR SHALLOW WATER MAGNETOHYDRODYNAMICS." Journal of Hyperbolic Differential Equations 01, no. 01 (March 2004): 171–95. http://dx.doi.org/10.1142/s021989160400007x.
Повний текст джерелаАнотація:
An advanced hyperbolic divergence cleaning scheme based on "generalized Lagrange multiplier" (GLM) for the equations of "shallow water magnetohydrodynamics" (SMHD) is presented. This scheme is based on the two-step method which is comprised of the standard finite-volume updating step for the nonlinear genuine SMHD system and the divergence cleaning step for the linear GLM-based Maxwell subsystem. The divergence cleaning step can be applied several times per each computational time step, in order to accelerate the transports of the divergence error out of the computational domain. The presented two-step method is compared with the standard GLM method based on operator splitting. It is shown that the standard operator-splitting based method has the shock dissipation problem, particularly when the multiple subcycles of the divergence cleaning step is performed per each time step. On the contrary, the introduction of the multiple subcycles for the new GLM–Maxwell subsystem does not suffer from the dissipation of the shocks, and produces better shock resolution. The presented method can be further applied to the full magnetohydrodynamics equations.
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Dumbser, Michael, Francesco Fambri, Elena Gaburro, and Anne Reinarz. "On GLM curl cleaning for a first order reduction of the CCZ4 formulation of the Einstein field equations." Journal of Computational Physics 404 (March 2020): 109088. http://dx.doi.org/10.1016/j.jcp.2019.109088.
Повний текст джерела
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Chiocchetti, Simone, Ilya Peshkov, Sergey Gavrilyuk, and Michael Dumbser. "High order ADER schemes and GLM curl cleaning for a first order hyperbolic formulation of compressible flow with surface tension." Journal of Computational Physics 426 (February 2021): 109898. http://dx.doi.org/10.1016/j.jcp.2020.109898.
Повний текст джерела
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Zanza, Alessio, Rodolfo Reda, Giuseppe Familiari, Stefania Annarita Nottola, Dario Di Nardo, Luca Testarelli, and Orlando Donfrancesco. "Wear Analysis of Four Different Single-File Reciprocating Instruments before and after Four Uses in Simulated Root Canals." Applied Sciences 12, no. 12 (June 20, 2022): 6253. http://dx.doi.org/10.3390/app12126253.
Повний текст джерелаАнотація:
The aim of this study is to assess the surface alterations of four reciprocating instruments before and after the shaping of four resin-simulated root canals. The following four different reciprocating instruments are selected: 10 Reciproc Blue (RB25), 10 WaveOne Gold (WOG), 10 EdgeOne Fire (EOF) and 10 recently introduced instruments OneRECI (OR), for a total of 40 new instruments. Before root canal shaping, each instrument is mounted on a stub in a standardized position and observed using a scanning electron microscope (SEM) to detect any surface alteration, such as microfractures, metal defects, deformations, blunt and disruption of cutting edges, debris, pitting and tip flattening. Micrographs are acquired at the level of the tip, 4 mm, 8 mm and 12 mm from it. After that, each instrument is used in four simulated resin root canals. SEM observation was repeated after the simulated clinical use to assess the wear resistance of the instruments. Surface alterations are registered before and after instrumentation and statistical analysis is performed using a Chi-Square test to verify homogeneity of defects distribution and GLM to evaluate the differences of RMS at baseline and after use for both groups (α level 0.05). Before simulated clinical uses, no alterations are found except for three cases of EOF with metal strips in correspondence to the tip, disruption of the cutting edge of WOG and oily spotting on two different OR. After simulated clinical use, EOF shows a statistically significant difference in terms of spiral distortion and flattening of the cutting edges. The OR shows the highest presence of debris despite the ultrasonic cleaning procedures. No instrument fractures are observed. EOF should be discarded after four clinical uses and carefully inspected after each insertion into root canals. Moreover, tough attention should be paid during disinfection and cleaning procedures after instrumentation considering the copious debris detected in each instrument, particularly in OR.
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Szigeti, Erika, János Kátai, István Komlósi, János Oláh, and Csaba Szabó. "The effect of genotype and the location of sampling on the mineral content of wool." Acta Agraria Debreceniensis, no. 69 (March 23, 2016): 157–60. http://dx.doi.org/10.34101/actaagrar/69/1805.
Повний текст джерелаАнотація:
Mineral supplementation is very important in high producing farm animals. The estimation of exact mineral intake is very difficult in forage eating animals, like sheep. Accessing of long term mineral status seems to be possible using wool mineral analysis. However several factors can affect the results. Therefore, the aim of this study was to test the effect of breed and sampling location on the mineral content of sheep wool. 20 Dorper and 20 Tsigai sheep were chosen from the same farm. Samples were obtained from 3 locations (withers, side and quarter) and tested for 8 elements: Ca, Mg, Na, Co, Cu, P, S, Se , Zn. The samples were cleaned with ethyl alcohol from organic contamination, then after adding nitric acid were mineral analized using ultrasonic cleaning unit. The samples were analysed with ICP-OES (Perkin-Elmer, Optima 3300 DV). Statistical analyses were carried out by GLM procedure of SAS statistical analyses software. Differences between means were checked with Tukey-test. Significant breed differences were detected in the case of Mg, Na, S, Se in spite of the same feeding regime. The wool mineral content were within the reference range. The sampling location had no effect on the mineral content of wool.
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Szigeti, Erika, János Kátai, István Komlósi, János Oláh, and Csaba Szabó. "The effect of wool staple length on the mineral content using the same sheep feeding regime." Acta Agraria Debreceniensis, no. 73 (August 29, 2017): 97–100. http://dx.doi.org/10.34101/actaagrar/73/1633.
Повний текст джерелаАнотація:
The wool of sheep is suitable to test the mineral supply; however, a number of factors could affect the results. The growth rate and length of staple can be very different according to season, physiological state and individual variation. These factors are likely to affect the quantity of minerals accumulated into the wool. Therefore, the purpose of this research was to examine whether there is a difference between the mineral content of wool nearly reached the full staple length and the freshly grown wool using the same feeding regime.10 Tsigai pregnant sheep have been selected randomly from the same farm. Wool samples were obtained from the withers, side and quarter with bended scissors. Samples were mineralized using nitric acid and hydrogen peroxide using ultrasonic cleaning unit. P, Ca, Mg, Na, S, Cu,Se and Zn content were determined by ICP-OES. Statistical analyses were carried out by SAS (SAS Institute Inc., Cary, NC) GLM procedure.Differences between means were tested by Tukey test. Significantly lower Ca, Na, P, Zn values were found in case of intensively grown wool. Sampling location did not affect the mineral content. Herd mineral supply was adequate. Our results suggest that intensively grown wool samples have to be used for mineral analyses.
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Santos, D., W. J. Pereira, D. S. Miranda, J. L. C. Souza, L. A. Borges, M. S. P. Paula, and M. C. Vieira. "Biometry of fruit, germination and morphogenesis in vitro of citrus after asepsis of seeds in different concentrations of sodium hypochlorite." Scientific Electronic Archives 13, no. 3 (March 1, 2020): 14. http://dx.doi.org/10.36560/1332020831.
Повний текст джерелаАнотація:
In tissue culture it is necessary to use seeds of good quality and free of pathogens in order to avoid damages in the work to be carried out in the laboratory. Therefore, strict cleaning of the seeds intended for in vitro cultivation is essential. Thus, the objective of this study was to evaluate fruit biometry, germination and morphogenesis of 'Cravo' (Citrus limonia Osbeck) and Persia Lima (Citrus aurantium) seeds in vitro submitted to different concentrations of NaClO for asepsis. Fruits of 'Cravo' lemon and Lima of Persia. Subsequently, they were transported to the Biotechnology Laboratory of the Goiano Federal Institute Campus Urutaí-GO, where they performed the biometric characterization of the fruits. The seeds of these fruits were submitted to treatment with sodium hypochlorite solution in different concentrations: 0,0; 1.0; 1.5; 2.0 and 2.5% for 10 minutes, constituting then five treatments for each variety and placed in an acclimatized growth room to analyze the results. The variables evaluated were: biometry of fruits and seedlings; oxidation indexes; germination; contamination; and types of contamination. NaClO doses were compared from 95% confidence intervals. The analyzes were performed using the glm () function of software R version 3.4.1. It was verified that the aseptic treatment with NaClO for lime and lemon was promising for the morphological processes of germination and development of seedlings, as well as for the control of contaminating agents in vitro.
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Kumar R, Naveen, Uday Kumar P, Bhaskar V, Sudershan R V, Kalpagam Polasa, Hemalatha R, and Sudip Ghosh. "Microbiological hazard identification in selective food products and their association with food safety practices in Hyderabad, India." Indian Journal of Microbiology Research 9, no. 3 (October 15, 2022): 223–31. http://dx.doi.org/10.18231/j.ijmr.2022.040.
Повний текст джерелаАнотація:
Microbiological risk assessment (MRA) is an emerging tool for evaluating the safety of food and water supplies. In this study, identification of microbial hazards in selected samples and their association with food safety practices were seen. Data were analyzed using Analysis of Variance (ANOVA) through the General Linear Models (GLM) procedure of the statistical analysis system software (SPSS version-11.5, 2003). The least significant differences were used to test means at p<0.05. Odds ratio (OR) values with 95% CI were computed to obtain the risk of the presence of the foodborne pathogen in a particular food. Analysis of 600 food samples indicated that (50%) was high in raw chicken samples followed by carrot salad (41%). The other emerging foodborne pathogens like (MRSA), , and were not detected in any of the food samples. Pathogens like (73.5%) in khoa, (45%) and (62.7%) in paneer were detected. A total of (n=143) cultures were analyzed for enterotoxin and coagulase enzyme. Nine cultures (6.3%) showed a positive result for enterotoxin production. For the risk assessment of contamination in foods, coagulase test and toxin production of isolates have to be evaluated. A significant association was found between the type of storage and log concentration of in khoa, whereas, with water for washing hands, the status of nails, and cleaning cloth were contributing to foodborne pathogens in other products. There is a need to provide food safety training to food handlers to improve food safety.
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Paschalia, Yustina Pacifica Maria, Anatolia Karmelita Doondori, Maria Salestina Sekunda, and Irwan Budiana. "Revitalization of Disaster Mitigation Management and Community Empowerment Through Community-Based Disaster Risk Reduction (CBDRR)." Jurnal Penelitian Pendidikan IPA 8, no. 5 (November 30, 2022): 2563–74. http://dx.doi.org/10.29303/jppipa.v8i5.2368.
Повний текст джерелаАнотація:
Currently, there are still many people who are not aware of their disaster-prone areas. This is exacerbated by the lack of maximum community empowerment in disaster prevention and management. This study aims to determine the effect of the implementation of community-based disaster risk reduction (CB DRR) on the knowledge and skills of the community in disaster mitigation. This research is a quasi-experimental study, with a non-randomized control group pre-test - post-test design. The population and sample in this study were all community administrators who were aware of the disaster. The instrument used is a questionnaire that has been tested for validity and reliability. Research procedures include administrative procedures and technical procedures. Data processing is done through the process of editing, coding, scoring, processing, and cleaning. Data analysis techniques include univariate analysis, bivariate analysis (paired t-test), and multivariate analysis (General Linear Model Repeated Measure or GLM-RM). The p-value on the knowledge and skills variables were both 0.000 (<0.05). The value of the Greenhouse-Geisser sig analysis on the knowledge and skills variables has the same p-value of 0.000 (<0.05) or there is a difference in the average knowledge and skills of respondents after being given CB DRR training. Conclusion: The CB DRR program training influences the knowledge and skills of the community in carrying out disaster mitigation with a changing trend seen from the first measurement to the last measurement.
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Astorkia, Hernandez, Bocs, Armentia, Herran, Ponce, León, et al. "Association Mapping Between Candidate Gene SNP and Production and Oil Quality Traits in Interspecific Oil Palm Hybrids." Plants 8, no. 10 (September 26, 2019): 377. http://dx.doi.org/10.3390/plants8100377.
Повний текст джерелаАнотація:
Oil palm production is gaining importance in Central and South America. However, the main species Elaeis guineensis (Eg) is suffering severely from bud rod disease, restricting the potential cultivation areas. Therefore, breeding companies have started to work with interspecific Elaeis oleifera × Eg (Eo × Eg) hybrids which are tolerant to this disease. We performed association studies between candidate gene (CG) single nucleotide polymorphisms (SNP) and six production and 19 oil quality traits in 198 accessions of interspecific oil palm hybrids from five different origins. For this purpose, barcoded amplicons of initially 167 CG were produced from each genotype and sequenced with Ion Torrent. After sequence cleaning 115 SNP remained targeting 62 CG. The influence of the origins on the different traits was analyzed and a genetic diversity study was performed. Two generalized linear models (GLM) with principle component analysis (PCA) or structure (Q) matrixes as covariates and two mixed linear models (MLM) which included in addition a Kinship (K) matrix were applied for association mapping using GAPIT. False discovery rate (FDR) multiple testing corrections were applied in order to avoid Type I errors. However, with FDR adjusted p values no significant associations between SNP and traits were detected. If using unadjusted p values below 0.05, seven of the studied CG showed potential associations with production traits, while 23 CG may influence different quality traits. Under these conditions the current approach and the detected candidate genes could be exploited for selecting genotypes with superior CG alleles in Marker Assisted Selection systems.
Дисертації з теми "GLM cleaning"
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Earney, Megan A. "Investigating the Effect of Mechanical Beach Cleaning on Nesting, Hatching and Emergence Success of Loggerhead (Caretta caretta) and Green (Chelonia mydas) Sea Turtles in Broward County, Florida." NSUWorks, 2017. http://nsuworks.nova.edu/occ_stuetd/454.
Повний текст джерелаАнотація:
Sea turtles face many threats to their populations globally. Loggerhead sea turtles (Caretta caretta) and green sea turtles (Chelonia mydas) are listed by the International Union for the Conservation of Nature Red List as Endangered. In Florida, loggerhead and green sea turtles nest along the coastline during April-September. Mechanical beach cleaning is an aesthetic service performed daily on some beaches in Florida to clean the wrack line and/or the entire beach of debris. Alterations made to beaches by methods such as mechanical beach cleaning have the potential to impact sea turtle nesting, hatching, and emergence success. Generalized linear mixed models were performed to investigate the impacts of mechanical beach cleaning on nesting, hatching and emergence success of loggerhead and green turtles from 1997-2015 in Broward County, Florida. The results showed mechanical beach cleaning had an effect on nesting success, however, hatching and emergence success were not affected by mechanical beach cleaning. These results indicate that mechanical beach cleaning cannot solely be used to determine sea turtle management or conservation guidelines in Broward County.
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Chiocchetti, Simone. "High order numerical methods for a unified theory of fluid and solid mechanics." Doctoral thesis, Università degli studi di Trento, 2022. http://hdl.handle.net/11572/346999.
Повний текст джерелаАнотація:
This dissertation is a contribution to the development of a unified model of
continuum mechanics, describing both fluids and elastic solids as a general
continua, with a simple material parameter choice being the distinction
between inviscid or viscous fluid, or elastic solids or visco-elasto-plastic
media. Additional physical effects such as surface tension, rate-dependent
material failure and fatigue can be, and have been, included in the same
formalism.
The model extends a hyperelastic formulation of solid mechanics in
Eulerian coordinates to fluid flows by means of stiff algebraic relaxation
source terms. The governing equations are then solved by means of high
order ADER Discontinuous Galerkin and Finite Volume schemes on fixed
Cartesian meshes and on moving unstructured polygonal meshes with
adaptive connectivity, the latter constructed and moved by means of a in-
house Fortran library for the generation of high quality Delaunay and Voronoi
meshes.
Further, the thesis introduces a new family of exponential-type and semi-
analytical time-integration methods for the stiff source terms governing
friction and pressure relaxation in Baer-Nunziato compressible multiphase
flows, as well as for relaxation in the unified model of continuum mechanics,
associated with viscosity and plasticity, and heat conduction effects.
Theoretical consideration about the model are also given, from the
solution of weak hyperbolicity issues affecting some special cases of the
governing equations, to the computation of accurate eigenvalue estimates, to
the discussion of the geometrical structure of the equations and involution
constraints of curl type, then enforced both via a GLM curl cleaning method,
and by means of special involution-preserving discrete differential operators,
implemented in a semi-implicit framework.
Concerning applications to real-world problems, this thesis includes
simulation ranging from low-Mach viscous two-phase flow, to shockwaves in
compressible viscous flow on unstructured moving grids, to diffuse interface
crack formation in solids.
Книги з теми "GLM cleaning"
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Beyond the Glitter: Everything You Need to Know to Buy, Sell, Care For, and Wear Gems and Jewelry Wisely. Adamas, 1989.
Знайти повний текст джерелаЧастини книг з теми "GLM cleaning"
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Seul, Andrzej, and Krzysztof Okarma. "Classification of Textures for Autonomous Cleaning Robots Based on the GLCM and Statistical Local Texture Features." In Advances in Intelligent Systems and Computing, 405–14. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-91189-2_40.
Повний текст джерелаТези доповідей конференцій з теми "GLM cleaning"
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Garcia, Sergio, Michael Mendez, Ramadan Ahmed, Hamidreza Karami, Mustafa Nasser, and Ibnelwaleed Hussein. "Effects of Pipe Rotation on the Performance of Fibrous Fluids in Horizontal Well Cleanout." In SPE Annual Technical Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210347-ms.
Повний текст джерелаАнотація:
Abstract The deposition of rock cuttings is a problem commonly faced during drilling, completion, and intervention operations. Using polymer-based fluids is a common technique to improve horizontal downhole cleaning. However, these fluids cannot always guarantee an efficient wellbore cleanout. One way to enhance cleanout efficiency is by rotating the drill pipe to mitigate the settling of solids and facilitate their removal. However, drill string rotation often increases equivalent circulating density (ECD). Therefore, this study explores how the impact of rotation on hole cleaning can be synergized by using fibrous fluids to perform cleanout at reduced rotational speeds with limited impact on ECD. The flow loop utilized for this study consists of a 48-ft long eccentric annular (5" × 2.375") test section. Each experiment began by forming a stationary bed of natural sand (average diameter of 1.2 mm) in the test section. High-viscosity and low-viscosity polymer-based suspensions with and without fibers were used. Drill pipe rotation speed was varied from 0 to 150 rpm. In each experiment, the flow rate was increased from 35 to 195 gpm stepwise. The equilibrium bed perimeter was measured at every test flowrate until a complete bed cleanout was achieved. As part of the test, flow rate, pressure gradient, and equilibrium bed height were measured. Rotational viscometers were used to measure fluid rheology before and after each test. Fiber particles improve the carrying capacity of the fluid by reducing the settling of solids and minimizing the re-deposition of particles. The results demonstrate the effectiveness of fiber in synergizing the effect of pipe rotation on hole cleanout performance in horizontal wellbores. The impact of fiber is more pronounced when used with low viscosity fluid. The cleanout performance of the low-viscosity fluid amplified significantly with rotation, almost entirely cleaning the bed at 75 gpm and a rotational speed of 50 RPM, compared to more than 195 gpm without rotation. Even more improvement could be achieved by adding a small amount of fiber (0.04% wt/wt). Furthermore, the fiber improved the cleanout performance of the high-viscosity fluid. The enhancement, however, was not as noticeable as with the low-viscosity fluid. In general, rotation combined with low-viscosity fibrous fluid exhibits the most effective sand cleaning performance. Rotating the pipe re-suspends the settled solids, which are then carried away by the fluids. Fiber particles enhance the fluid's ability to carry solids.
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Seul, Andrzej. "Monochromatic textures' features extraction using extended GLCM approach for classification of autonomous cleaning robot work area." In 2018 International Interdisciplinary PhD Workshop (IIPhDW). IEEE, 2018. http://dx.doi.org/10.1109/iiphdw.2018.8388361.
Повний текст джерела
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Lee, John, Ahmadi Tehrani, Steve Young, and Christine Nguyen. "Viscoelasticity and Drilling Fluid Performance." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23908.
Повний текст джерелаАнотація:
Viscoelastic properties of drilling fluids are not often measured due to a lack of understanding of their impact on fluid performance as well as a lack of field equipment suitable for such measurements. A study has been conducted recently to evaluate the viscoelastic properties of xanthan gum and invert drilling fluids and their impact on barite suspension quality and rheology. Both a Brookfield YR-1 rheometer and a Bohlin Gemini 150 rheometer were used to generate data for comparison. The impact of viscoelasticity on steady-state rheology, thixotropy and shear thinning was evaluated using a multi-speed rheometer. A soon-to-be-adopted API recommended procedure was used to measure the barite sag tendency under dynamic conditions. Aqueous solutions of xanthan gum showed that viscoelasticity, shear thinning and thixotropy increased with increasing polymer concentration. When the solutions were weighed up with barite, they became more viscoelastic, slightly more thixotropic, but less shear thinning. Proper suspension of barite was observed at a xanthan gum concentration of 2 lb/bbl without any other additives. Compared to xanthan-barite suspensions, invert drilling fluids of similar density exhibited a greater viscoelasticity but less thixotropy and shear thinning. Treatment of invert drilling fluids with viscoelastic polymers resulted in a further enhancement of viscoelasticity and thixotropy, but a slight deterioration in shear thinning. Barite suspension quality showed a certain degree of correlation with viscoelasticity as well as steady-state rheology; however, these properties were temperature dependent for invert drilling fluids. Hydraulic analyses indicated that viscoelastic additives can impact fluid viscosity thus affecting pressure loss, equivalent circulating density and hole cleaning. Viscoelasticity enhancement may be used to improve barite suspension quality under certain conditions, but its impact on hydraulics must be carefully considered.
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Belayneh, Mesfin, and Bernt S. Aadnøy. "Effect of Nano-Silicon Dioxide (SiO2) on Polymer/Salt Treated Bentonite Drilling Fluid Systems." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54450.
Повний текст джерелаАнотація:
Recently the application of nanomaterial is attracting the oil and gas industry. The preliminary nanomaterials research results show an improving performance of cement, drilling fluid and Enhanced Oil Recovery. In this paper, the effect of nano Silicon dioxide (SiO2) on polymer (HV-CMC, Xanthan gum, LV-CMC) and salt (KCl, NaCl) treated bentonite drilling fluid systems has been studied at room temperature. The results show that the performance of nano SiO2 in bentonite mud system depends on its concentration and the types of salt and polymer systems used. In the considered fluid systems, it is also observed that the addition of about 0.06% SiO2 influences rheology, and filtrate loss of the drilling fluid systems. The viscoelasticity of the selected best system further studied and their hole -cleaning and hydraulics performances are simulated. The overall result shows that the formulated optimum concentration of nano-system shows good performances and rheological behavior.
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Fisher, Andrew, Jiten Kaura, Matthew Kratzer, Ken Oyler, Ron Reutzel, Michael Teoh, Scott Thomassen, and Javier Vives. "Innovative Technologies Deliver Operational Objectives in a Multi-Well, Ultra-Deepwater, Managed Pressure Drilling and Completions Campaign." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206012-ms.
Повний текст джерелаАнотація:
Abstract The deepwater development field in the western Gulf of Mexico (GoM) presents an array of complex challenges for ultra-deepwater drilling operations. The four well campaign was particularly challenging due to extreme water depths, remote location, well trajectory and a narrow pressure environment, 350-100 kpa (50-150 psi), for extended reservoir laterals. The authors highlight the use of innovative technology employed to drill and complete wells in the western GoM deployment, coupled with the first-ever use of controlled mud level (CML), managed pressure drilling technology in the Gulf of Mexico. The approach of selecting the fluid systems to achieve the objectives and the use of hydraulics modeling software with CML modeling capability in the design, planning and execution phases of the project allowed for fluid design optimization. The results were a successful drilling and completion campaign managing multiple fluids systems and operations on an ultra-deepwater, dual-activity drill ship in water depths more than 8,500 ft (2,591 m). The authors discuss the initial use of a low equivalent circulating density (ECD), flat-rheology synthetic based fluid (SBF) designed for narrow margin drilling applications and the transition to the deployment of a newly developed high-performance water-based mud (HPWBM) optimizing the operations to drill the intermediate intervals for final two wells. The authors also will discuss use of the reservoir drill-in fluid (RDF) and solids-free screen running fluids (SF-SRF), designed specifically for use in these open holes, gravel pack completions at hole angles upwards of 90°. Operational efficiencies derived from use of these fluids include ECD management, hole cleaning, directional performance, reduction in downhole losses, and the elimination of non-productive time (NPT) in a narrow margin environment with no loss of rate of penetration (ROP). Additional efficiencies include the seamless transition from derived from use of water-based fluids for drilling and completion phases. Use of the CML technology allowed for precise control of the hydrostatic pressure on wells that previously would not have been technically feasible to drill or complete. The novel use of the newly developed HPWBM on this campaign enabled reduced health, safety and environmental (HSE) exposure impact, increased tank and rig cleaning efficiency, and the elimination of a wellbore cleanout run since the entire well was drilled with only water-based fluids. The fluids were successfully employed in the four wells drilled and completed in a managed pressure environment utilizing CML technology.
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Monreal, Gabriel, Frank Zamora, Hans Henrik Ovrebo, Peter Orizondo, and Otto Soidinsalo. "Characterization of a New Green Material for Offshore Well Completions and Downhole Treatments." In Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/31870-ms.
Повний текст джерелаАнотація:
Abstract In oil and gas well construction during the drillouts or wellbore cleaning process, one of the most critical functions of land and offshore completions fluids is the ability to suspend solids effectively under extreme downhole conditions. Conventional agents such as xanthan gum, HEC and numerous other polymers have historically been used to accomplish this function, albeit with limitations. Functionally, these commonly used polymers depend primarily upon viscosity rather than elastic characteristics to suspend solids and require intensive chemical processing that leads to high deployment cost. Recently microfibrillated cellulose (MFC) has been investigated as a prospective suspending agent in carrier fluids for extreme downhole conditions. MFC is a unique type of superfine cellulose fibrils obtained from fully sustainable sources that have been subjected to proprietary treatment procedures, resulting in fibril bundles consisting of lateral dimensions in the sub-micron scale and lengths up to micron scale with abundant terminal hydroxyl functional groups. When dispersed into aqueous solutions, the resulting fluid has been characterized to have several favorable rheological, chemical and mechanical properties. Rheological measurements show the viscoelasticity of MFC dispersions is dominated by their storage modulus (G′ > G″) even with fluids formulated with as low as 0.25 wt% (about 20 lbm MFC /1000 gallons). The result is a suspension that exhibits superior particle suspension properties compared on a mass basis to conventional materials such as guar, CMC, HEC and xanthan gum. In addition, MFC solutions exhibit comparatively high viscosities at low shear rates but thin by several orders of magnitude at high shear, a characteristic that implies less work on surface equipment while having the ability to suspend solids at very low pump rates. MFC dispersions also have an excellent brine tolerance, demonstrating stable suspensions over weeks in fluids containing up to 150,000 mg/L TDS. The dispersions are stable at downhole relevant temperatures, applicable at low and high pH levels and resistant to shear degradation. Finally, MFC originates from natural resources and is environmentally benign and biodegradable. This paper describes the comprehensive characterization of the rheological and suspension properties that distinguish MFC from other conventionally used materials and make it fit-for-purpose as a robust, environmentally benign and high-performance suspending agent for downhole applications.
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Ebuzeme, Ifeanyichukwu, Oladipo Olatunji, and Babatope Olufemi. "Factorial Design Validation of an Environmentally Benign Water-Based Drilling Fluid from Sweet Potato Peels at Elevated Temperatures." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/207097-ms.
Повний текст джерелаАнотація:
Abstract In recent years, several research types have been carried out to produce environmentally-benign drilling fluid additives using locally sourced substances. Still, the formulation of a more effective and cheaper viscosifier for a better hole cleaning ability that lowers risk in lost circulation zones, especially at higher temperatures, remains a critical research subject. This study examines the use of Sweet Potato Peels Extract (PPE), a more readily available by-product, as a drilling fluid additive. A 23 factorial experiment that considers temperature, PPE and Xanthan Gum (X.G.) as factor variables and viscosity as a response variable was conducted for field optimisation. In this research, the PPE and other commercial polymers were measured at different concentrations and combined in a specified ratio of 1:1 by mass to verify the levels of interaction between the additives on the mud weight, yield point (Y.P.), and plastic viscosity (P.V.) of the formulated drilling mud. The additives’ effects were then recorded using a mud balance, a viscometer, and a heater for temperature variance. The results were then compared with the control mud to ascertain the additives’ effectiveness. Experimental results revealed that the PPE and X.G. increased the Y.P. and P.V. at 104 °F and 176 °F, respectively. On adding 6 g of X.G. to the control mud (8.97 ppg), at 104 °F and 176 °F, the Y.P. increased by 88% and 11%, respectively, and the 3 g PPE + 3 g X.G. gave a better inference at 104 °F and 176 °F with a 92% and 38% increase respectively. This increase is a result of higher potassium content in the PPE from chemical laboratory analysis. Apart from the optimum ratio by mass of 1:1 above, the combination effects or results are shown using the factorial design experiment. The factor variables were modelled into a mathematical equation that indicates PPE additive as the most significant parameter on the yield point. The second component of viscosity, plastic viscosity (P.V.), followed a similar trend. Furthermore, PPE and X.G.'s effect on plastic viscosity at 176 °F decreased slightly with an increase in the control mud's salinity. This novel combination offers a more cost-effective and better-performing viscosifier than the conventional X.G. from the above results. The model helps predict downhole conditions better as it shows the interactive effects of the various additives and can help inform decisions at the surface. A better hole cleaning ability, lower risk in lost circulation zones, and reduced Non-Productive Time would be the benefits of using this formulation.
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Hongbo, Chen, Okesanya Temi, Kuru Ergun, Heath Garett, and Hadley Dylan. "A Generalized Model for the Field Assessment of Drilling Fluid Viscoelasticity." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205953-ms.
Повний текст джерелаАнотація:
Abstract Recent studies highlight the significant role of drilling fluid elasticity in particle suspension and hole cleaning during drilling operations. Traditional methods to quantify fluid elasticity require the use of advanced rheometers not suitable for field application. The main objectives of the study were to develop a generalized model for determining viscoelasticity of a drilling fluid using standard field-testing equipment, investigate the factors influencing drilling fluid viscoelasticity in the field, and provide an understanding of the viscoelasticity concept. Over 80 fluid formulations used in this study included field samples of oil-based drilling fluids as well as laboratory samples formulated with bentonite and other polymers such as partially-hydrolyzed polyacrylamide, synthesized xanthan gum, and polyacrylic acid. Detailed rheological characterizations of these fluids used a funnel viscometer and a rotational viscometer. Elastic properties of the drilling fluids (quantified in terms of the energy required to cause an irreversible deformation in the fluid's structure) were obtained from oscillatory tests conducted using a cone-and-plate type rheometer. Using an empirical approach, a non-iterative model for quantifying elasticity correlated test results from a funnel viscometer and a rotational viscometer. The generalized model was able to predict the elasticity of drilling fluids with a mean absolute error of 5.75%. In addition, the model offers practical versatility by requiring only standard drilling fluid testing equipment to predict viscoelasticity. Experimental results showed that non-aqueous fluid (NAF) viscoelasticity is inversely proportional to the oil-water ratio and the presence of clay greatly debilitates the elasticity of the samples while enhancing their viscosity. The work efforts present a model for estimating drilling fluid elasticity using standard drilling fluid field-testing equipment. Furthermore, a revised approach helps to describe the viscoelastic property of a fluid that involves quantifying the amount of energy required to irreversibly deform a unit volume of viscoelastic fluid. The methodology, combined with the explanation of the viscoelasticity concept, provides a practical tool for optimizing drilling operations based on the viscoelasticity of drilling fluids.