Journal articles: 'Structural Propping'

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Zhu, Qingzhong, Bo Wang, Xin Zhao, Chunchun Liu, Qing Yu, Liwen Zhang, Tao Hou, and Guangjie Sang. "Effect of Coalbed Methane Well Fracturing on Slope Stability of Open-Pit Coal Mine: A Case Study of Shengli East No. 2 Open-Pit Coal Mine." Advances in Civil Engineering 2020 (July 16, 2020): 1–16. http://dx.doi.org/10.1155/2020/4708274.

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The impact of hydraulic fracture from CBM well fracturing on slope stability of the Shengli East No. 2 open-pit coal mine is analyzed by numerical simulation and limit equilibrium methods. The interference effect of coalbed methane (CBM) well fracturing on slope stability of the open-pit coal mine promotes the coordinated development of CBM, and open-pit coal is discussed before and after coal mining. It shows that nearly horizontal fractures are formed in the coal seam due to CBM well fracturing, of which the dynamic facture length and propping fracture length are 137.2 m and 105.2 m, respectively. Moreover, the dynamic fracture height is 137.2 m and propping fracture height is 130.6 m. At the location of perforation, the dynamic fracture width is 0.873 cm and average propping fracture width is 0.111 cm. The CBM well fracturing barely imposed any effect on slope stability before open-pit coal mining. The maximum vertical displacement at the toe of slope induced by fracturing is 0.293 mm. In situations with and without CBM well fracturing, vertical stress distributions in the toe, top, and interior of slope have no obvious difference. There is some extent of vertical stress increase within the interior of slope, which is merely 0.2 MPa higher than that in the condition of initial in situ stress equilibrium. The presence of hydraulic fractures has little effect on the overall displacement of slope during coal mining; and there is no obvious difference between the slope stability during coal mining and the slope stability impacted by fracturing. According to the results of limit equilibrium method and numerical simulation, the overall slope stability coefficient is 1.5–1.97, which accords with the requirements of the Design Code for Open-Pit Mine of Coal Industry (GB50197-2015). Therefore, more attentions should be paid to the ways of excavation and sloping during coal mining, avoiding slope instability caused by excavation.

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Parthasarathy, Arunachalam, Smriti Mahalingam, Subhiksha Sridharan, Sai Pavan Kalyan Chethala, and R. Vidjeapriya. "Comparative Analysis of 3D Steel and Glulam Trusses Using ABAQUS." IOP Conference Series: Materials Science and Engineering 1197, no. 1 (November 1, 2021): 012006. http://dx.doi.org/10.1088/1757-899x/1197/1/012006.

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Abstract This study aims at developing an innovative and sustainable 3D truss system that can be applied in a variety of scenarios where intermediary propping is a hindrance. One prominent and pertinent application of such a system is in archaeological sites where long spans and no intermediary propping are desired. Previous research and studies have developed an innovative 3D steel truss for the same application. This study aims to further the innovation by providing a more sustainable alternative through Glulam and Glulam-Bamboo hybrid variations which are able to withstand similar loads as that of the steel truss but offering more sustainability and less impact on the environment as well as a light weight alternative. The results of such an alternative truss system are discussed here. One obvious problem faced with the alternative wood system was the large deflections observed and also certain regions with impermissible stresses. In addition, the proposed joint in the Glulam truss has been modelled and analyzed. It was found that the Glulam truss with lateral restraints at every quarter length of the span showed the best results in terms of deflection and stress developed. Also, the Glulam-Bamboo hybrid truss without any lateral restraints proved to be an equally effective alternative from a structural standpoint. The proposed joint system for the glulam truss also proved to be effective. The study concludes with a cost benefit analysis (CBA) between the steel, glulam and Glulam-Bamboo hybrid systems, which compares the viability of the proposed designs from an economic standpoint. The CBA shows that about 46% and 48% of costs are minimized on employing Glulam, Glulam- Bamboo respectively, instead of using Steel for the truss.

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Blanco, Haydee, Yosbel Boffill, Ignacio Lombillo, and Luis Villegas. "Monitoring Propping System Removal in Domes and Tie-Rod Slackening from a Historical Building." Journal of Structural Engineering 145, no. 5 (May 2019): 04019033. http://dx.doi.org/10.1061/(asce)st.1943-541x.0002297.

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Ivanova, Maria N. "Inequality, financialization, and the US current account deficit." Industrial and Corporate Change 28, no. 4 (March 19, 2019): 707–24. http://dx.doi.org/10.1093/icc/dtz005.

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Abstract The US has run a persistent current account deficit since 1982. Its growth particularly accelerated in the early 2000s, and the deficit peaked at about 6% of US GDP in 2006. Coincidentally, the distribution of income and wealth has grown progressively unequal, while the so-called financialization of the US economy has deepened. This article argues that the concomitant processes of persistent current account deficits, rising inequality, and deepening financialization are not merely coincidental but can be traced to common causes arising from the global restructuring of US production through foreign direct investment and offshoring, which has underlain the structural transformation of the US economy since the 1980s. On the one hand, the US is the world’s biggest exporter of capital and recipient of foreign investment income; on the other hand, it is the biggest importer of foreign goods, often produced with the involvement of US capital. Ultimately, deindustrialization at home—a major factor behind the loss of middle-wage, middle-class jobs, and thus of rising income inequality—and the transnationalization of US production have boosted corporate profits, thereby propping up and accelerating the financialization of the US economy.

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Tan, Yong, Bin Wei, Xin Zhou, and Yanping Diao. "Lessons Learned from Construction of Shanghai Metro Stations: Importance of Quick Excavation, Prompt Propping, Timely Casting, and Segmented Construction." Journal of Performance of Constructed Facilities 29, no. 4 (August 2015): 04014096. http://dx.doi.org/10.1061/(asce)cf.1943-5509.0000599.

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Kathalikkattil, Amal Cherian, Kamal Kumar Bisht, Núria Aliaga-Alcalde, and Eringathodi Suresh. "Synthesis, Magnetic Properties, and Structural Investigation of Mixed-Ligand Cu(II) Helical Coordination Polymers with an Amino Acid Backbone and N-Donor Propping: 1-D Helical, 2-D Hexagonal Net (hcb), and 3-DinsTopologies." Crystal Growth & Design 11, no. 5 (May 4, 2011): 1631–41. http://dx.doi.org/10.1021/cg101587h.

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Wang, Ping, TianLi Gu, Zhanwu Gao, Jiayong Fan, Hai Huang, Zhan Qu, Qiang Han, and Zongxiao Ren. "Stability Evaluation of Proppant in Fractures of Gas Storage in Yulin Gas Field." Advances in Civil Engineering 2022 (May 28, 2022): 1–12. http://dx.doi.org/10.1155/2022/2044561.

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In nearly a hundred years of construction, underground gas storage has become the main natural gas storage and peak regulation means in the world. For the gas storage, the large production and high flow rate of the gas well in the actual production process will cause the backflow of proppant filled in the supporting fracture, which will bring great harm to the gas field production. In this article, when the proppant fracture reaches a stable state in the process of gas injection and production, the stress of proppant particles is analyzed, the critical velocity of proppant reflux is calculated, and then the critical production model is established; calculate the permeability change during proppant migration, then calculate the fluid velocity and production, and determine the fluid velocity range of injection and production wells in gas storage. The parameter sensitivity of velocity and flow model is analyzed. The results show that with the increase of closure stress, the critical gas flow and critical gas velocity of proppant backflow gradually increase, and the proppant filling layer is more stable. The smaller the thickness and width of the filling layer, the greater the critical gas flow and critical gas velocity of proppant backflow, the more stable the proppant filling layer, and the lesser the chance of backflow. The higher the saturation, the lower the critical gas velocity, and the more prone the proppant to reflux. It has important guiding significance for realizing the optimization of gas well production and maintaining efficient production efficiency.

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Kwietniewski, M., D. Miedzińska, and T. Niezgoda. "Fem Analysis of Proppant Sticking in Rock Cracks." Archives of Civil Engineering 64, no. 2 (September 28, 2018): 55–65. http://dx.doi.org/10.2478/ace-2018-0016.

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AbstractThe problem of effective gas extraction from Polish shale rocks is an interesting research subject for scientists. A properly selected proppant, which protects cracks from closing during the fracturing process, inestimably contributes to an increase of extraction. Grains of proppant are transported along with a fracturing medium to reach the deepest regions of the crack. The proper support of the crack provides an easy flow of gas, therefore it is important in terms of extraction efficiency. This paper shows the interactions of a proppant grain with the crack surface in shale rock. FEM analysis was conducted to observe the stress region, which is generated as a result of pressing the grain into the crack surface. A model of a sphere which was pressed into the rock model with constant velocity was applied. The received results of stress depend on material properties and a range of proppant grain pressing.

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Kühnel, K., R. Krick, R. A. Busse, A. Scacioc, and M. Thumm. "Structural and functional characterization of the two phosphoinositide binding sites of PROPPINs." Acta Crystallographica Section A Foundations of Crystallography 69, a1 (August 25, 2013): s316. http://dx.doi.org/10.1107/s0108767313097262.

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Masłowski, Mateusz, and Małgorzata Labus. "Preliminary Studies on the Proppant Embedment in Baltic Basin Shale Rock." Rock Mechanics and Rock Engineering 54, no. 5 (March 3, 2021): 2233–48. http://dx.doi.org/10.1007/s00603-021-02407-0.

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AbstractProppant embedment is a serious issue that reduces fracture width and conductivity. The paper presents the results of experiments on embedment phenomena on a shale rock from the region of the Baltic Basin, which is regarded as an unconventional gas deposit. A novel laboratory imaging procedure was implemented to the proppant embedment visualization. The tests were performed for conditions corresponding to the average reservoir conditions occurring in the studied deposit formation. The parameters characterizing damage of the surface of the fracture faces by the grains of proppant material, after the application of axial compressive stress to two shale core samples with proppant placed in between, are presented. The tests were carried out for rock samples pre-saturated with fracturing fluid. The obtained results of relatively low total effective penetration depth of proppant grains into the walls of the fracture (0.293 mm), and high effective width of fracture with proppant material after hydraulic fracturing (87.9%), indicate the proper selection of proppant and fracturing fluid for the properties of the rock and the reservoir conditions. The results of the experiments present a range of embedment parameters, that have not been widely described before. The test procedure presented in the article is a good method for assessing the vulnerability of a deposit rock to embedment phenomenon.

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Lengyel, Tamás, Attila Varga, Ferenc Safranyik, and Anita Jobbik. "Coupled Numerical Method for Modeling Propped Fracture Behavior." Applied Sciences 11, no. 20 (October 17, 2021): 9681. http://dx.doi.org/10.3390/app11209681.

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Hydraulic fracturing is a well-known production intensification technique in the petroleum industry that aims to enhance the productivity of a well drilled mostly in less permeable reservoirs. The process’s effectiveness depends on the achieved fracture conductivity, the product of fracture width, and the permeability of the proppant pack placed within the fracture. This article presents an innovative method developed by our research activity that incorporates the benefit of the Discrete—and Finite Element Method to describe the in situ behavior of hydraulic fractures with a particular emphasis on fracture conductivity. DEM (Discrete Element Method) provided the application of random particle generation and non-uniform proppant placement. We also used FEM (Finite Element Method) Static Structural module to simulate the elastic behavior of solid materials: proppant and formation, while CFD (Computational Fluid Dynamics) module was applied to represent fluid dynamics within the propped fracture. The results of our numerical model were compared to data of API RP-19D and API RP-61 laboratory measurements and findings gained by publishers dealing with propped fracture conductivity. The match of the outcomes verified the method and encouraged us to describe proppant deformation and embedment and their effect as precisely as possible. Based on the results, we performed sensitivity analysis which pointed out the impact of several factors affecting proppant embedment, deformation, and fracture conductivity and let one be aware of a reasonable interpretation of propped hydraulic fracture operation. However, DEM–CFD coupled models were introduced regarding fracturing before, to the best of our knowledge, the developed workflow of coupling DEM–FEM–CFD for modeling proppant-supported fracture behavior has not been applied yet, thus arising new perspectives for explorers and engineers.

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Tu, Xiaofei, and Wendy Xie. "The Kojiki/Nihon Shoki Mythology and Chinese Mythology: Theme, Structure, and Meaning." Religions 12, no. 10 (October 18, 2021): 896. http://dx.doi.org/10.3390/rel12100896.

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This essay will compare myths found in the Kojiki and the Nihon Shoki with thematically and structurally similar Chinese myths, and other Japanese texts, in order to shed light on the meanings of both Japanese and Chinese mythology. The authors’ approach is partly in the critical textual study tradition that traces back to Gu Jiegang and Tsuda Sokichi, and partly informed by comparative mythologists, such as Matsumae Takeshi, Nelly Naumann, and Antonio Klaus, with attention to Proppian and Levi-Straussian motifs in structural studies. First, we shall discuss some common themes in Chinese and Kojiki/Nihon Shoki myths. Second, we shall point out common structures in both Chinese and Japanese myths. Finally, we shall try to show how such common themes and structures could potentially help us understand the meanings of the myths in discussion.

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Tamulonis, Kathryn. "A methodology for integrating unconventional geologic and engineering data into a geocellular model." Interpretation 8, no. 1 (February 1, 2020): B13—B33. http://dx.doi.org/10.1190/int-2018-0138.1.

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Unconventional field development and well performance analysis encompass multiple disciplines and large data sets. Even when seismic and other data sets are not available, geologists can build geocellular models to determine factors that improve operational efficiency by incorporating well log, geosteering, stratigraphic, structural, completion, and production data. I have developed a methodology to integrate these data sets from vertical and horizontal wells to build a sequence stratigraphic and structurally framed geocellular model for an unconventional Marcellus Formation field in the Appalachian Basin, USA. The model would benefit from additional data sets to perform a rigorous investigation of performance drivers. However, the presented methodology emphasizes the value of constructing geocellular models for fields with sparse data by building a geologically detailed model in a field area without seismic and core data. I used third-order stratigraphic sequences interpreted from vertical wells and geosteering data to define model layers and then incorporate completion treating pressures and proppant delivered per stage into the model. These data were upscaled and geostatistically distributed throughout the model to visualize completion trends. Based on these results, I conclude that geologic structure and treating pressures coincide, as treating pressures increase with stage proximity to a left-lateral strike-slip fault, and completion trends vary among third-order systems tracts. Mapped completion issues are further emphasized by areas with higher model proppant values, and all treating pressure and proppant realizations for each systems tract have the greatest variance away from data points. Similar models can be built to further understand any global unconventional play, even when data are sparse, and, by doing so, geologists and engineers can (1) predict completion trends based on geology, (2) optimize efficiency in the planning and operational phases of field development, and (3) foster supportive relationships within integrated subsurface teams.

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Zhao, Zhongcong, Tongyi Liu, Pingya Luo, Yan Li, Jianxin Liu, Jiangmin Cheng, and Yi Yu. "Performance and field implementation of a new fracturing fluid consisting of hydrophobically associating polyacrylamide and anionic surfactant." Journal of Polymer Engineering 36, no. 1 (January 1, 2016): 13–21. http://dx.doi.org/10.1515/polyeng-2014-0344.

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Abstract The fundamental cause of the proppant suspension behavior in hydraulic fracturing fluids lies in its internal microcosmic network structure and structural strength. In addition to chemical crosslinking, another method to form a network structure is established in this paper. Hydrophobically associating polyacrylamide and an anionic surfactant self-assembly process was applied to form a network structure. Compared with crosslinked hydroxypropyl guar gel, the new fracturing fluid even has better proppant suspending properties in static conditions. The capability does not result from crosslinkage but from reinforced physical associations between chains. The performance of this new fracturing fluid was tested and the results showed that it can fully satisfy the requirement of fracturing fluid. Field test shows excellent stimulation effects during its applications in 400 wells in eight oilfields in China.

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Votinov, Alexander, Valeriy Seredin, Igor Kolychev, and Sergey Galkin. "Possibilities of accounting the fracturing of Kashiro-Vereyskian carbonate objects in planning of proppant hydraulic fracturing." Записки Горного института 252 (December 17, 2021): 861–71. http://dx.doi.org/10.31897/pmi.2021.6.8.

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One of the effective methods of oil production intensification for heterogeneous Kashiro-Vereyskian clay-carbonate sediments of the Volga-Ural oil and gas bearing province is proppant hydraulic fracturing. Prospects of realization for this technology are considered in the article on the example of the Vereyskian development object of Moskud’inskoye field. Based on the analysis of rocks samples investigations of Vereyiskian sediments, lithological types of carbonate rocks differing in their structural features are distinguished. Tomographic investigations of rock samples were carried out, as a result of which the rock fracturing for some lithotypes was determined and studieds. Under natural geological conditions, depending on the degree of fracturing progression and technological conditions of development, these intervals may or may not be involved in well operation. When hydraulic fracturing is performed, potentially fractured areas that are not in operation can be successfully added to oil production. Based on analysis of hydrodynamic well investigations, the fracturing of the Vereyskian object of the Moskud’inskoye field was studied on the basis of the Warren-Ruth model. With the help of geological and technological indicators of development, prediction fracturing was obtained, which was used for the construction of the natural fracturing scheme. Areas of both pore and fractured reservoirs development were identified on the deposit area. As a result of statistical analysis, the influence of fracturing on efficiency of proppant hydraulic fracturing was determined. Based on the linear discriminant analysis, a statistical model for predicting the efficiency of proppant fracturing was developed. It was shown that in addition to natural fracturing, the results are most strongly influenced by specific proppant yield, formation pressure, permeability of the remote bottomhole zone and skin effect. Based on the developed model, prospective production wells of the Moskud’inskoye field are identified for proppant hydraulic fracturing.

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Krick, Roswitha, Ricarda A. Busse, Andreea Scacioc, Milena Stephan, Andreas Janshoff, Michael Thumm, and Karin Kühnel. "Structural and functional characterization of the two phosphoinositide binding sites of PROPPINs, a β-propeller protein family." Proceedings of the National Academy of Sciences 109, no. 30 (July 2, 2012): E2042—E2049. http://dx.doi.org/10.1073/pnas.1205128109.

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Zhao, Xiaohuan. "From Story to Script: towards a Morphology of The Peony Pavilion––a Dream/ Ghost Drama from Ming China." Acta Orientalia Vilnensia 7, no. 1-2 (January 1, 2006): 189–208. http://dx.doi.org/10.15388/aov.2006.3762.

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University of Otago, Donghua University This article is an attempt to analyze the dramatic structure of the Mudan ting 牡丹亭 (Peony Pavilion) as a piece of fantasy which Tang Xianzu 湯顯祖 (1550–1616) created through the utilisation of structural devices and techniques of magic tales. The particular model adopted for the textual analysis is that formulated by Vladimir Propp in Morphology of Russian Folktale.This paper starts with a comparison of Russian magic tales Propp investigated for his morphological study and Chinese zhiguai 志怪 tales which provide the prototype for the Mudan ting with a view of justifying the application of the Proppian model. The second part of this paper is devoted to a critical review of the Proppian model and method in terms of function versus non-function, tale versus move, and character versus tale / theatrical role. Further information is also given in this part as a response to challenges and criticisms this article may incur as regards the applicability of the Proppian model in inter-cultural and inter-generic studies.Part Three is a morphological analysis of the dramatic text with a focus on the main storyline revolving around the hero and heroine. In the course of textual analysis, the particular form and sequence of functions is identified, the functional scheme of each move presented, and the distribution of dramatis personae in accordance with the sphere(s) of action of characters delineated. Finally this paper concludes with a presentation of the overall dramatic structure and strategy of this play.

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Frolova, Ksenia, Polina Grigoreva, Konstantin Lezhnev, and Grigoriy Paderin. "A model of the proppant flowback: setup of the theoretical framework." Mathematics and Mechanics of Complex Systems 7, no. 2 (August 10, 2019): 175–87. http://dx.doi.org/10.2140/memocs.2019.7.175.

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McElhoe, Jennifer A., and Rachel A. Brennan. "Effects of Chitin Purity and Proppant Loading on the Bioremediation of Chloroethenes." Journal of Environmental Engineering 138, no. 8 (August 2012): 862–72. http://dx.doi.org/10.1061/(asce)ee.1943-7870.0000541.

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Mihail, Silin, Magadova Lyubov, Malkin Denis, Krisanova Polina, Borodin Sergei, and Filatov Andrey. "Applicability Assessment of Viscoelastic Surfactants and Synthetic Polymers as a Base of Hydraulic Fracturing Fluids." Energies 15, no. 8 (April 13, 2022): 2827. http://dx.doi.org/10.3390/en15082827.

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Hydraulic fracturing (HF) is currently the most widespread and effective method of oil production stimulation. The most commonly used fracturing fluid is crosslinked guar gels. However, when using these systems, problems such as clogging of the pore space, cracking, and proppant packing with the remains of the undestroyed polymer arise. Therefore, the efficiency of the hydraulic fracturing process decreases. In this work, compositions based on viscoelastic surfactants (VES) and synthetic polymers (SP) were considered as alternatives capable of minimizing these disadvantages. Most often, the possibility of using a composition as a fracturing fluid is evaluated using rotational viscometry. However, rotational viscometry is not capable of fully assessing the structural and mechanical properties of fracturing fluid. This leads to a reduced spread of systems based on VES and SP. This paper proposes an integrated approach to assessing the effectiveness of a water-based fracturing fluid. The proposed comprehensive approach includes an assessment of the main characteristics of water-based fracturing fluids, including an analysis of their structural and mechanical properties, which is based on a combination of rotational and oscillatory rheology and a comparative analysis of methods for studying the influence of fluids on the reservoir rock. The use of the developed approach to assess the technological properties of fracturing fluids makes it possible to demonstrate the potential applicability of new, unconventional fracturing fluids such as systems based on VES and SP.

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Chen, Ming, Tiankui Guo, Yushi Zou, Shicheng Zhang, and Zhanqing Qu. "Numerical Simulation of Proppant Transport Coupled with Multi-Planar-3D Hydraulic Fracture Propagation for Multi-Cluster Fracturing." Rock Mechanics and Rock Engineering 55, no. 2 (November 12, 2021): 565–90. http://dx.doi.org/10.1007/s00603-021-02694-7.

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Lemmon, Mark A. "Pleckstrin homology (PH) domains and phosphoinositides." Biochemical Society Symposia 74 (January 12, 2007): 81–93. http://dx.doi.org/10.1042/bss2007c08.

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PH (pleckstrin homology) domains represent the 11th most common domain in the human proteome. They are best known for their ability to bind phosphoinositides with high affinity and specificity, although it is now clear that less than 10% of all PH domains share this property. Cases in which PH domains bind specific phosphoinositides with high affinity are restricted to those phosphoinositides that have a pair of adjacent phosphates in their inositol headgroup. Those that do not [PtdIns3P, PtdIns5P and PtdIns(3,5)P2] are instead recognized by distinct classes of domains including FYVE domains, PX (phox homology) domains, PHD (plant homeodomain) fingers and the recently identified PROPPINs (b-propellers that bind polyphosphoinositides). Of the 90% of PH domains that do not bind strongly and specifically to phosphoinositides, few are well understood. One group of PH domains appears to bind both phosphoinositides (with little specificity) and Arf (ADP-ribosylation factor) family small G-proteins, and are targeted to the Golgi apparatus where both phosphoinositides and the relevant Arfs are both present. Here, the PH domains may function as coincidence detectors. A central challenge in understanding the majority of PH domains is to establish whether the very low affinity phosphoinositide binding reported in many cases has any functional relevance. For PH domains from dynamin and from Dbl family proteins, this weak binding does appear to be functionally important, although its precise mechanistic role is unclear. In many other cases, it is quite likely that alternative binding partners are more relevant, and that the observed PH domain homology represents conservation of structural fold rather than function.

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M., Ramakrishnan. "THE MODALITY OF PROPPIAN “FALSE HERO”: NEITHER A HERO NOR A VILLAIN IN (FOLK) NARRATIVES AND REAL LIFE." ShodhKosh: Journal of Visual and Performing Arts 3, no. 2 (July 26, 2022): 89–96. http://dx.doi.org/10.29121/shodhkosh.v3.i2.2022.150.

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Being the contemporary of Roland Barthes and also prominent scholar in French Semiotics, and also known for founding the Parisian School of Semiotics, Algirdas Julien Greimas, with his formal trainings in structural linguistics shaped the theory of signification by adding plastic semiotics. Indeed, his masterly contributions that had given a new direction in the study of narratives include the famous semiotics square, actantial model, concepts of isotopy, narrative programme and the semiotics of the natural world. However, the actantial model developed by Greimas in 1966 provided an analytical tool for studying various actions carried out by different actors (“actants”) in a real or fictional story. Although developed from the suggestion given by Vladimir Propp that his [Propp’s] seven dramatis personae such as ‘villain’, ‘donor’, ‘helper’, ‘princess/sought-for-person’, ‘dispatcher’, ‘hero’, and ‘false hero’ could be reduced further, Greimas proposed the actantial narrative schema with six actants that manifest their movements of relationship along the line founded on knowledge and power. However, the ‘false hero’ as one of the dramatis personae could be seen as important as, and as similar to, others in the narrative structure, its modality is quite interesting, and it tends to warrant an academic discussion to contemplate its morphology. Taking few examples from folktales and drawing insights from the Greimasian actantial model, this study presents the semiotic account of the ‘false hero’ to highlight the fact that the ‘false hero’ occupies a significant place not only within the real and fictional stories but also in daily life, by explaining the veridictory modality structure of truth and falseness. By drawing examples from folktales, this article comprehends the nature of the ‘false hero’, who is neither a hero nor a villain, for providing a grammatical framework that facilitates our smooth handling of the notion that is indispensably occupying our everyday life. Therefore, the significance of this paper is that it is lessening our efforts to decipher the nature of different characters in different forms of narratives and their presentations in different media.

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Hou, Lei, Yiyan Cheng, Xiaoyu Wang, Jianhua Ren, and Xueyu Geng. "Effect of slickwater-alternate-slurry injection on proppant transport at field scales: A hybrid approach combining experiments and deep learning." Energy 242 (March 2022): 122987. http://dx.doi.org/10.1016/j.energy.2021.122987.

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Li, Zheng, Jingyi Wang, and Ian D. Gates. "Fracturing Gels as Analogs to Understand Fracture Behavior in Shale Gas Reservoirs." Rock Mechanics and Rock Engineering 53, no. 10 (May 25, 2020): 4345–55. http://dx.doi.org/10.1007/s00603-020-02153-9.

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Abstract Hydraulic fracturing is widely used in the exploitation of unconventional reservoirs, such as shale gas and tight gas. However, a full understanding of the activation of natural fractures, prediction of fracture growth, distribution of proppant, and network fracture system effectiveness remain unresolved. The onset of fracturing in the media requires energy and this is due to the buildup of pressure within the rock due to continuous injection of fluid. In other words, when the energy associated with the injection fluid reaches the fracture strength of the rock, the fracture initiates and propagates into the formation. Here, we use gelatin in hydraulic fracturing laboratory tests and compare the results to a modified radial hydraulic fracturing theory. The mechanics of the gelatin, procedures to make a testing gelatin block, and procedures to conduct the test are described. The results show that the fracture evolving behaviours from experiments are well matched by the theory. The results are then scaled up to understand fracture growth behaviour in a tight rock reservoir.

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Zhong, Ying, Ergun Kuru, Hao Zhang, Jianchao Kuang, and Jiping She. "Effect of Fracturing Fluid/Shale Rock Interaction on the Rock Physical and Mechanical Properties, the Proppant Embedment Depth and the Fracture Conductivity." Rock Mechanics and Rock Engineering 52, no. 4 (November 20, 2018): 1011–22. http://dx.doi.org/10.1007/s00603-018-1658-z.

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Cheng, Chaojie, and Harald Milsch. "Hydromechanical Investigations on the Self-propping Potential of Fractures in Tight Sandstones." Rock Mechanics and Rock Engineering, May 21, 2021. http://dx.doi.org/10.1007/s00603-021-02500-4.

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AbstractThe hydromechanical properties of single self-propping fractures under stress are of fundamental interest for fractured-rock hydrology and a large number of geotechnical applications. This experimental study investigates fracture closure and hydraulic aperture changes of displaced tensile fractures, aligned tensile fractures, and saw-cut fractures for two types of sandstone (i.e., Flechtinger and Fontainebleau) with contrasting mechanical properties, cycling confining pressure between 5 and 30 MPa. Emphasis is placed on how surface roughness, fracture wall offset, and the mechanical properties of the contact asperities affect the self-propping potential of these fractures under normal stress. A relative fracture wall displacement can significantly increase fracture aperture and hydraulic conductivity, but the degree of increase strongly depends on the fracture surface roughness. For smooth fractures, surface roughness remains scale-independent as long as the fracture area is larger than a roll-off wavelength and thus any further displacement does not affect fracture aperture. For rough tensile fractures, these are self-affine over a larger scale so that an incremental fracture wall offset likely leads to an increase in fracture aperture. X-ray microtomography of the fractures indicates that the contact area ratio of the tensile fractures after the confining pressure cycle inversely correlates with the fracture wall offset yielding values in the range of about 3–25%, depending, first, on the respective surface roughness and, second, on the strength of the asperities in contact. Moreover, the contact asperities mainly occur isolated and tend to be preferentially oriented in the direction perpendicular to the fracture wall displacement which, in turn, may induce flow anisotropy. This, overall, implies that relatively harder sedimentary rocks have a higher self-propping potential for sustainable fluid flow through fractures in comparison to relatively soft rocks when specific conditions regarding surface roughness and fracture wall offset are met.

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Köse, Talha, and Bilgehan Öztürk. "A Sea of Change in the MENA Region: External Intervention in Libya." Insight Turkey, November 2020, 113–38. http://dx.doi.org/10.25253/99.2020224.08.

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External interventions by both regional and global powers in Libya have not been a scarcity after the 2011 revolution. With the turn of 2014, however, the nature of external interventions became more of a military one especially with the imposition of Haftar’s rule in the east by several counter-revolutionary regional and global actors. At the point that the same counter-revolutionary alliance attempted to geopolitically strangulate Turkey both via propping up hostile and authoritarian regimes in the Middle East and North Africa, and also excluding it from the prospect of exploiting the riches of the Eastern Mediterranean, Turkish intervention materialized in early 2020. This study attempts to explain the various motivations of the major intervening actors in Libya, namely France, Russia, Egypt, and the UAE with a special focus on Turkey. Structural realist perspective is used to elucidate the international interventions to the Libyan civil war. The nature of the uncertainty emanating from the regional transformation motivated the key actors to get militarily involved in the Libyan crisis. The actors with defensive motives are more likely to stick to the conflict despite the risks of escalation.

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Zhang, Nanlin, Zhangxin Chen, Zhifeng Luo, Pingli Liu, Weiyu Chen, and Fushen Liu. "Effect of the phase-transition fluid reaction heat on wellbore temperature in self-propping phase-transition fracturing technology." Energy, December 2022, 126136. http://dx.doi.org/10.1016/j.energy.2022.126136.

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30

Moos, Renata. "Intercultural differences in the structure of Cinderella: A Proppian and storygraph analysis of Russian, Scottish and Hungarian fairy tales." Freeside Europe Online Academic Journal, no. 1 (Alumni) (2020). http://dx.doi.org/10.51313/alumni-2020-4.

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Some fairy tales are known worldwide, but in a variety of forms. This study attempts to seek intercultural differences in the structure and in the narrative of fairy tales, through the analysis of the Cinderella fairy tale versions from Scotland, Russia and Hungary. The structural analysis applies the Proppian method (1995). This morphological analysis proves the theory of Propp regarding the structural unity of the folktales, despite their differences in content and idiom. At the same time, some definitions of the functions as basic elements of the structural schema appear to be arguable. The rhetorical analysis of the tales is performed by the storygraph method of Söter (1988) to discover cultural influence on the narratives. Although, some differences were detected, in general all investigated fairy tales of this study resemble the Western rhetorical style. Overall, the results suggest that the influence of the cultural context are more traceable in the rhetorical patterns of the narratives than in their morphological structure.

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31

Fan, Ming, Yanhui Han, and Cheng Chen. "Thermal–Mechanical Modeling of a Rock/Proppant System to Investigate the Role of Shale Creep on Proppant Embedment and Fracture Conductivity." Rock Mechanics and Rock Engineering, September 13, 2021. http://dx.doi.org/10.1007/s00603-021-02642-5.

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32

Xiao, Bo, Tingxue Jiang, and Shicheng Zhang. "Novel Nanocomposite Fiber-Laden Viscoelastic Fracturing Fluid for Coal Bed Methane Reservoir Stimulation." Journal of Energy Resources Technology 139, no. 2 (September 14, 2016). http://dx.doi.org/10.1115/1.4034548.

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As coal has strong adsorption characteristics and well-developed natural fracture systems, an improper choice of fracturing fluid can result in significant challenges for coal bed methane exploitation, including damage to the coal formation and ineffective creation and propagation of hydraulic fractures. Viscoelastic surfactant (VES) fracturing fluid has become a preferred option because of its easy flowback and the resultant minimal damage. A novel nanocomposite fiber with substantially improved functional and structural properties was synthesized by introducing nanoparticles into conventional polyester fiber. Subsequently, a nanocomposite fiber-laden VES (NFVES) fracturing fluid was developed and evaluated in the laboratory. The results show that the fiber disperses well in the fluid and that the addition of a small amount (0.5%) of fiber substantially enhances the proppant-carrying capacity of the fluid. To achieve a proppant-carrying capacity equivalent to a standard VES, the surfactant concentration can be decreased from 2.5% to 1%, which not only reduces costs but also significantly lowers adsorption of the surfactant by the seam and rock surfaces. In addition, rod micelles with less surfactant added are more easily broken. Addition of 0.7% nanocomposite fiber reduced the tube friction by 20% at shearing rate of 5000 s−1. The nanocomposite fiber also effectively prevents backflow of the proppant and mitigates leak-off of fluid and aggregation of coal scraps. Continuous degradation of the fiber occurs over time at formation temperatures, thus reducing the potential damage to the coal seam. The strong performance of this NFVES fracturing fluid in the laboratory evaluations indicates the great potential and development prospects for coal bed methane reservoir stimulation using this fluid.

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Alagoz, Ekrem, Haotian Wang, Rodney T. Russell, and Mukul M. Sharma. "New Experimental Methods to Study Proppant Embedment in Shales." Rock Mechanics and Rock Engineering, October 2, 2021. http://dx.doi.org/10.1007/s00603-021-02646-1.

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Shao, Jiaxin, Lijun You, Na Jia, Yili Kang, Mingjun Chen, and Xiaowen Lei. "Salt crystal: Natural proppant for enhancing shale reservoir production." Energy, September 2022, 125569. http://dx.doi.org/10.1016/j.energy.2022.125569.

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Luo, Jin, Qi Zhang, Derek Elsworth, and Qi Zhao. "Competing Effects of Proppant and Surface Roughness on the Frictional Stability of Propped Fractures." Rock Mechanics and Rock Engineering, January 3, 2023. http://dx.doi.org/10.1007/s00603-022-03215-w.

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Huang, Jian, Yue Hao, Randolph R. Settgast, Joshua A. White, Khalid Mateen, and Herve Gross. "Validation and Application of a Three-Dimensional Model for Simulating Proppant Transport and Fracture Conductivity." Rock Mechanics and Rock Engineering, October 3, 2022. http://dx.doi.org/10.1007/s00603-022-03092-3.

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Hou, Lei, Derek Elsworth, Fengshou Zhang, Zhiyuan Wang, and Jianbo Zhang. "Evaluation of proppant injection based on a data-driven approach integrating numerical and ensemble learning models." Energy, November 2022, 126122. http://dx.doi.org/10.1016/j.energy.2022.126122.

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Xi, Xun, Zoe K. Shipton, Jackie E. Kendrick, Andrew Fraser‑Harris, Julien Mouli-Castillo, Katriona Edlmann, Christopher I. McDermott, and Shangtong Yang. "Mixed-Mode Fracture Modelling of the Near-Wellbore Interaction Between Hydraulic Fracture and Natural Fracture." Rock Mechanics and Rock Engineering, June 21, 2022. http://dx.doi.org/10.1007/s00603-022-02922-8.

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AbstractThe interaction between hydraulic fractures (HF) and natural fractures (NF) is one of the most fundamental phenomena in hydraulic fracturing. The near-wellbore interaction between HF and NF significantly affects fracking-related operations including the injected fluid flow, proppant transport and well productivity. However, the nature of fracturing modes, combined with hydro-mechanical coupling, poses great difficulties and challenges in addressing this problem. Literature review suggests that little research has been undertaken on near-wellbore interaction, especially considering the fully coupled hydro-mechanical mixed-mode fracturing process. This paper develops a new fracture model incorporating the Mohr–Coulomb criterion with the cohesive crack model. The model is implemented into ABAQUS solver by in-house FORTRAN subroutines. The rock matrix and cohesive crack interfaces are both coupled with fluid flow. The developed model is then validated by comparing the results with analytical solutions and experimental results. Moreover, the effects of approach angle, NF location, in situ stress, cohesion strength and friction angle of NF, and flow rate on the near-wellbore interaction are investigated. Three interaction modes, i.e., cross, deflect and offset, are reproduced through the numerical method. The crack deflection into NF is a shear-dominated mixed-mode fracture. A high injection pressure in the wellbore tends to drive the HF to cross a NF located close to the wellbore. The smaller the cohesion strength and friction angle of NF is, the larger the offsetting ratio is. A low injection flow rate can help activate natural fractures near the wellbore when intersected by HF.

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Journal articles on the topic 'Structural Propping'

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