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Published in last 1 year | In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year| Most Downloaded in Recent Year Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Application and Prospect of Fluid Mobility in Oilfield Development TAN Fengqi, MA Chunmiao, LI Xiankun, JING Yuqian Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (1): 1-20.   DOI: 10.11885/j.issn.1674-5086.2022.06.18.02 Abstract （182）   HTML （25）    PDF（pc） （10022KB）（376）       Knowledge map    Save The study on fluid mobility in micro-pore-throat is of great significance for accurate evaluation and efficient development of the reservoir, and it is also the necessary basis for enhanced oil recovery of oil-gas reservoir. According to the differences of research objects, the research methods of fluid mobility in pore throats are divided into three dimensions: mineral composition, pore structure and fluid production. NMR technology can quickly and accurately determine the commonly used movable fluid parameters such as movable fluid saturation, movable fluid porosity and irreducible water saturation, and then effectively evaluate and predict the productivity of various oil and gas reservoirs. At present, the major oil fields at home and abroad have adopted the method of combining NMR with other experimental means to determine the production law of fluid in the reservoir, and have achieved good application results in different types of reservoirs such as tight glutenite, carbonate rock, coal seam and oil shale. In addition, in order to achieve effective exploration and development of different types of oil and gas resources, it is necessary to clarify the control factors of fluid mobility in the reservoir. Based on the existing research results, the control factors of fluid mobility can be divided into macro and micro aspects. The macro factors include sedimentary environment, diagenesis and lithofacies type, while the micro factors include pore throat structure, reservoir physical properties, mineral composition, water film thickness and other factors. At present, although the research methods of fluid mobility have been abundant and have achieved good application results in the evaluation of different types of oil and gas resources, further research and exploration are needed for greater accuracy and wider coverage in its application. In the future development, new ideas and methods such as pore network model, reservoir numerical simulation, multi parameter evaluation index, simultaneous geochemical parameters and so on can be comprehensively applied so as to deeply reveal the percolation mechanism of movable fluid in the micro-pore-throat, and continuously improve the accuracy of comprehensive evaluation of movable fluid, to provide geological basis for the rational formulation of reservoir development plan, and to promote the efficient development of the petroleum industry. Reference | Related Articles | Metrics Select Development Status of High-efficiency Rock-breaking and Speed-increasing Technologies for Deep Shale Gas Horizontal Wells ZHU Xiaohua, LI Rui, LIU Weiji, LI Zhilin, LU Dengyun Journal of Southwest Petroleum University(Science & Technology Edition)    2023, 45 (4): 1-18.   DOI: 10.11885/j.issn.1674-5086.2021.04.05.01 Abstract （347）   HTML （230）    PDF（pc） （2990KB）（773）       Knowledge map    Save At present, China has basically formed the economic exploitation of shallow shale gas engineering technology system, and is moving towards deep layer (more than 3 500 m) exploitation. Deep shale gas has great development potential with rich reserve. But the problems of slow drilling speed and high cost caused by high hardness, high plasticity and high abrasiveness of deep rock are very prominent. Therefore, the efficient rock breaking methods and influencing factors in deep shale gas drilling are introduced. We analyze and summarize the efficient transmission technology of reducing friction and torsion in deep shale gas horizontal wells to improve bit breaking power; and we analyze and summarize new technologies of bit and tooth with strong attacking power and longer service, technology of rock breaking parameter enhancement by using speed-raising tool to assist bit and speed-raising tool-bit parameter matching technology that is suitable for deep shale gas, and briefly describe several new non-mechanical and efficient rock breaking methods, aiming to providing a reference for future economic and efficient exploration and development of deep shale gas. Reference | Related Articles | Metrics Select Optimization Study of the Horizontal Well and Injection-production Pattern in an Ultra-low-permeability Reservoir FAN Jianming, QU Xuefeng, WANG Chong, ZHANG Qingzhou, WANG Xuanru 西南石油大学学报(自然科学版)    2018, 40 (2): 115-128.   DOI: 10.11885/j.issn.1674-5086.2017.03.22.03 Abstract （190）   HTML    PDF（pc） （1891KB）（732）       Knowledge map    Save This study forms the basic principle of an injection-production well design for a horizontal well in an ultra-lowpermeable reservoir based on the understanding of the breakthrough, effect analysis, and mining rule of the horizontal well in an ultra-low-permeable reservoir to solve the problem of stable production. The following points are discussed:(1) the expanding range of the three-dimensional space of an artificial pressure crack is the foundation of the injection-production pattern design; (2) the direction of the well arrangement is perpendicular to the maximum principal stress; (3) the lateral displacement of the well network is the main supplementary energy; (4) the well spacing, distance, and horizontal section length should be optimized to improve the water flooding control area ratio; and (5) spacing must be reduced and an effective use of the gap between the reserves must be realized to improve the intensity of the single section. The technical direction and policy of further improving the development effect of horizontal wells are put forward based on the basic principles of the injection-production well pattern design along with the combination of field statistics and theoretical analysis to (1) improve the level of the single segment output; (2) improve the level of the well network pressure and optimize the well spacing for 500-600 m (the horizontal segment lengths of the reservoirs of the I, Ⅱ, and Ⅲ classes were 500-550 m, 450-500 m, and 400-450 m, respectively, and the reservoir row spacings of the I, Ⅱ, and Ⅲ classes were 150, 120~130, and 100~120 m, respectively; (3) optimize the water injection intensity of the single well using the technique of low and moderate water injection; and (4) determine the reasonable initial output of the horizontal well using the relationship between the amount of deposit, distance, and velocity of the water line. The reasonable production flow pressure injection was slightly greater than the saturation pressure before the water injection was effective, and was not less than 2/3 of the saturated pressure. Reference | Related Articles | Metrics Select A Review of the Application Progress of Machine Learning in Oil and Gas Industry MIN Chao, DAI Boren, ZHANG Xinhui, DU Jianping Journal of Southwest Petroleum University(Science & Technology Edition)    2020, 42 (6): 1-15.   DOI: 10.11885/j.issn.1674-5086.2020.06.05.03 Abstract （852）   HTML （72）    PDF（pc） （1130KB）（1356）       Knowledge map    Save With the rise of deep learning in recent years, machine learning has been further developed in the oil and gas field. However, due to the particularity and complexity of the oil and gas industry, there is no training sample base suitable for deep learning, nor a targeted model establishment and selection method system. In addition, the uninterpretability of methods such as deep learning leads to the high dependence of learning models on the environment, which restricts the popularization and application of machine learning in the oil and gas industry. Starting from the development stage of machine learning, this paper introduces the major breakthroughs and problems in the application of machine learning in various fields of oil and gas industry. Then, suggestions are given on the processing methods and sample building of different types of data in the oil and gas industry, and how to carry out model adaptability analysis, etc. Finally, the development potential and research direction of machine learning in oil and gas artificial intelligence are proposed. Reference | Related Articles | Metrics Select Evaluation of Uncertainties for Pore-pressure Taking Eaton Method asan Example Zang Yanbin;Wang Ruihe;Wang Zizhen;Zhang Rui;He Yingming; 西南石油大学学报(自然科学版)    2012, 34 (4): 55-61.   Abstract （469）      PDF（pc） （670KB）（844）       Knowledge map    Save In view of the difficulties the uncertainty of pore-pressure brought to the drilling engineering design and construction， the concept of pore pressure uncertainty is present，and the calculation model for pore pressure uncertainty is derivated for Eaton method. An example is analyzed using synthesis data from PG block in northeast Sichuan region. The method presented here gives the range and main influencing factors of pore pressure uncertainty，and the influence law of related factors to uncertainty. The calculated results are in correspondence with actual mud density and the results of gas production test，which proves that the evaluation method of pore pressure uncertainty is feasible，the results has high accuracy and validity. Related Articles | Metrics Select Analysis of Policy and Enlightenment on Treatment of Fracturing Fluid in Shale Gas Production Between China and the United States CHEN Xuezhong, LU Youchang, WU Yiyi, MA Lili Journal of Southwest Petroleum University(Science & Technology Edition)    2021, 43 (5): 212-219.   DOI: 10.11885/j.issn.1674-5086.2021.02.25.02 Abstract （204）   HTML （5）    PDF（pc） （1453KB）（360）       Knowledge map    Save Fracturing flowback fluid is complex in composition and difficult in treatment because it is rich in chemical additives and is affected by formation water and cuttings. Based on the comparison of relevant regulations on water environmental protection and fracturing flowback fluid treatment in shale gas development between China and the United States, we find out the following problems in the environmental supervision of shale gas development in China:the unified coordination organization for the environmental supervision of shale gas development has not yet been formed; the environmental regulations and standards related to shale gas development are not perfect; the basic scientific research is weak. Therefore, the countermeasures of shale gas fracturing fluid management in China are establishing on a sound regulatory system and carrying out the entire process environmental supervision, improving basic scientific research, and enhancing the technology and management system. Reference | Related Articles | Metrics Select PERFORMANCE EVALUATION OF ENCAPSULATED BREAKER IN FRACTURING FLUIDS WU Min YIE Yan 西南石油大学学报(自然科学版)    2002, 24 (6): 68-70.   DOI: 10.3863/j.issn.1000-2634.2002.06.020 Abstract （942）      PDF（pc） （234KB）（991）       Knowledge map    Save An encapsulated breaker is composed of particles that are coated with a waterproof coating , which can reduce releasing rate of the breaker. The encapsulated breaker can be used in fracturing treatment at higher concentrations and has littleinfluence on viscosities of fracturing fluid. Laboratory study on performance of the encapsulated breaker has been conducted by comparing with other products from abroad and home , which has indicated a method and results of rheological properties of the fracturing fluid. Related Articles | Metrics Select Investigation Advances in Rheological Properties of Water Based Foam Jing Jiaqiang;Dai Kemin;Yang Lu;An Yunpeng;Zhao Chuandong 西南石油大学学报(自然科学版)    2013, 35 (1): 173-178.   Abstract （351）      PDF（pc） （465KB）（1031）       Knowledge map    Save Water based foams have been widely used in oil well drilling，foam flooding，mineral flotation and other fields. Because of the complexity and instability of their own structure，the exact description of their rheological properties should consider various factors such as liquid film drainage，gas diffusion，foam mass and structure，foam compressibility，wall slip， bubble size compared with measuring system，environment temperature and pressure and so on. This leads to no generally accepted theory for their rheological behavior. A widely available method of controlling the wall slip is to increase surface roughness of the flow channels such as rotor surface or pipe wall during the experimental investigation，and some theoretical modification methods deduced from some appropriate hypotheses have a better adaptability. The volume equalized constitutive equation assumes that the friction factor of foam flow in pipe is a constant，which can solve the difficulty of its pressure drop calculation due to the foam compressibility to some extent. It is widely believed that the foam rheological properties can be satisfactorily described by power law or Herschel-Bulkley models，but the existence of“yield stress”for the aqueous foams is being disputed due to different measurement conditions. Related Articles | Metrics Select Advances in the Interface Detection of Gas-liquid Two-phase Pipe-flow Research JIANG Junze, YONG Qiwei, QIAN Haibing, JIANG Xinsheng, HUANG Yanqi Journal of Southwest Petroleum University(Science & Technology Edition)    2021, 43 (2): 138-148.   DOI: 10.11885/j.issn.1674-5086.2020.03.05.02 Abstract （334）   HTML （10）    PDF（pc） （637KB）（553）       Knowledge map    Save The accuracy detection of the interface is not only the basis of the mechanics analysis, but also a powerful measure for the investigation of two-phase flow. Gas-liquid occurs widely in the energy, power, chemical engineering, petroleum and aviation, and there is an obvious topological and transient interface which is difficult to be detected accurately. The paper has summarized the interface detection technology and numerical simulation method.The decetion technology includes capacitance, conductivity, optical, ray, heat acoustic, nuclear magnetic resonance; the WMS, PT and PIV technologies are developed in recent years which enhance the precision of the interface detection; the numerical simulation includes PIC, MAC, ALE, VOF, Level Set, and so on. The methods are compared and analyzed with the advantages and boundedness, and some strategy and tendency are proposed, which may provide some references for the two-phase flow investigation. Reference | Related Articles | Metrics Select COMPARATIVE STUDY ON DYNAMICS BEHAVIORS OF THE FULL DRILLSTRING BETWEEN GAS DRILLING AND MUD DRILLING LIN Tie-jun LIAN Zhang-hua ZHANG Jun-liang WEI Chen-xing CHEN Shi-chun; 西南石油大学学报(自然科学版)    2011, 33 (1): 139-143.   DOI: 10.3863/j.issn.1674-5086.2011.01.025 Abstract （839）      PDF（pc） （538KB）（885）       Knowledge map    Save The movement of the full drillstring is a very complex nonlinear dynamical process.It is impossible to get very much perfect analytic solution and there is high cost of experiment.Thus，based on elasticsplastic mechanics，rock mechanics and drilling string mechanics and the drilling data of some gas well，this paper successfully establishes the complex nonlinear dynamics finite element 3D realtime drilling model of several kilometerslong irregular borehole，and real conditions are considered，such as mutual action between drill bit and rock，unknown contact between tapered drillstring and hole，effect of complicated 3D well trajectories (azimuth angle，deviation angle) and real drilling parameters (WOB，rotating speed).The timevarying data at each point on the long drillstring can be obtained after simulated，including displacement，axial force，stress，bending moment，torque，vibration，and contact force.These data are processed to obtain the perilous stress zones，the severe abrasion areas，the lowest fatigue life section which possibly lead to failure and difference between gas drilling and mud drilling，which can provide theoretical foundations for the application of drillstring failure and prevention.Furthermore，it is useful of this model to study drilling string mechanics，hole deviation control and equipment in air drilling. Related Articles | Metrics Select Mechanisms of Fluid-rock Interaction and Systems of Soaking in Shale Gas Reservoir: A Research Review YANG Zhaozhong, DU Huilong, YI Liangping, LI Xiaogang, GOU Liangjie Journal of Southwest Petroleum University(Science & Technology Edition)    2023, 45 (6): 80-94.   DOI: 10.11885/j.issn.1674-5086.2022.05.04.02 Abstract （114）   HTML （11）    PDF（pc） （2081KB）（190）       Knowledge map    Save The production practice of shale gas reservoirs shows that soaking the well can significantly increase the initial production after fracturing operation. However, there is a lack of a comprehensive review and summary of the existing literature when it comes to which scientific-soaking system should be selected in a specific situation. Based on the research results of domestic and foreign scholars on the mechanism of reservoir reconstruction and damage, model, influencing factors and engineering process of fluid-rock reaction during shale gas well soaking, we systematically summarize the yield-increasing mechanism and the existing soaking system. The results show that the fluid rock reaction is the essence of soak production under reservoir conditions, and the degree of fluid-rock reaction is the key to formulate soaking system. The interaction of fluid-rock during well soaking can both contribute and damage the reservoir. The transformation of the reservoir includes the initiation and expansion of micro fractures and gas liquid imbibition displacement; the damage to the reservoir includes solid phase plugging during fluid-rock reaction and water phase trap caused by fracturing fluid intrusion. Establishing an unknown bridge between fluid-rock interaction and effective pore structure parameters of reservoir is the key to the study of the systems of soaking. In view of the cross scale and highly nonlinear problems that restrict the research on fluid-rock interaction, the author proposed an effective fracture characterization model based on molecular dynamics and an industrial artificial intelligence optimization model for shale gas well soak. Reference | Related Articles | Metrics Select Research Progress of the Ultrasonic Detection in Phase Behavior of Fluidsin Porous Media Chen Hao;Yang Shenglai;Yu Donghai;Li Fangfang;Zhang Xing 西南石油大学学报(自然科学版)    2013, 35 (1): 67-73.   Abstract （379）      PDF（pc） （385KB）（1010）       Knowledge map    Save So far，the study of the phase behavior of hydrocarbon fluids has been relatively mature. It could supply corresponding theoretical guidance and technical support for the efficient development of the oil and gas reservoirs. However，the effect of porous media on phase behavior mostly is ignored. Therefore，it is crucial to study the phase behavior of fluids in porous media with due consideration of the interactions of the fluids and porous media. With the further development in this field，advantages of the ultrasonic detection such as no limit of pressure and temperature，no effect on fluid compositions，low cost and no harm to human beings have received increasingly attention and the technique is gradually being used in phase behavior of fluids in porous media. In this paper，with reference to abundant literature at home and abroad，detection mechanism of the ultrasonic wave is described briefly and research advances of the ultrasonic detection in phase behavior of gas hydrates and condensate gas system is summarized emphatically. And，the existing problems and future research of this technique are also identified. Related Articles | Metrics Select Reflection on Domestic and Foreign Research Status of Subsurface Safety Valves and Their Domestication LIU Wei, YANG Song, MAI Yu, WANG Yimin, JIANG Shikai 西南石油大学学报(自然科学版)    2018, 40 (3): 164-174.   DOI: 10.11885/j.issn.1674-5086.2016.08.02.02 Abstract （266）   HTML    PDF（pc） （2504KB）（908）       Knowledge map    Save Motivated by the insufficient research and development of subsurface safety valves in China, the structure and classification methods of subsurface safety valves are introduced, and oil tube recovery products from four global oil-service companies and domestic enterprises are analyzed. The comparison shows that foreign companies have characteristic structures and functions of subsurface safety valves but share similar core technologies. The products can adapt to different well depths, temperatures, and pressures; however, domestic products are only applicable for shallow wells and low-pressure environments. The latest research conditions of subsurface safety valves in both China and foreign countries are studied, and the comparative analysis shows that foreign research mainly focuses on the safe reliability and functional diversity, while domestic research only focuses on the preliminary design and either indoor or outdoor detection. Eventually, key technologies of the urgent settlement of the domestication of subsurface safety valves, as well as solutions and thoughts are proposed by considering the present technical state of subsurface safety valves in China. Reference | Related Articles | Metrics Select Research Progress on Functionalization Nanocarbons for Enhanced Oil Recovery LIU Rui, CHEN Zezhou, GAO Shi, PU Wanfen, DU Daijun Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (1): 64-75.   DOI: 10.11885/j.issn.1674-5086.2022.06.13.02 Abstract （124）   HTML （7）    PDF（pc） （2390KB）（182）       Knowledge map    Save Owing to their amphiphilic, and high aspect ratio, functionalization nanocarbons display multifaceted properties of surfactant, molecular film, colloid, liquid crystal molecule and polymer, stimulating their unique advantages and application potential application in enhanced oil recovery. This paper summarizes the common and unique characteristics of the structures and properties of the nanocarbons composing of 1D carbon nanotube and 2D graphene, the preparation methods, and their functionalization routes. The lipophilic-hydrophilic tailoring modification for nanocarbons on harsh reservoir temperature and salinity is proposed. Guided by the universal problem of low sweep efficiency and low micro-displacement efficiency of water flooding reservoirs, the absorption and self-assembly mechanisms of functionalization nanocarbons at water/oil and water/rock interfaces are analyzed, and multi-dimensional characterizations and information-based physical simulations of functionalization nanocarbons are summarized. Based on the nano-scale molecular and cross-scale characteristics and water/oil/rock interface effects, the coupled enhanced oil recovery mechanisms of functionalization nanocarbons on enhancing sweep volume and improving displacement efficiency are elucidated. The papers ends with a critical and perspective outline on the existing problems in the large-scale application of functionalization nanocarbons and their route to the low-carbon cost for enhanced oil recovery. Reference | Related Articles | Metrics Select A Review on Pyrolysis Experimentation on Hydrocarbon Generation Tang Qingyan;Zhang Mingjie;Zhang Tongwei;Shang Hui;Lin Yao 西南石油大学学报(自然科学版)    2013, 35 (1): 52-62.   Abstract （388）      PDF（pc） （631KB）（1166）       Knowledge map    Save Experimental pyrolysis simulation on hydrocarbon generation from organic-rich sources is an important approach to the evaluation of hydrocarbon generation potential and resource assessment，and it can be used to simulate the physical and chemical evolution of organic matters under geological conditions. The results of pyrolysis experiment provides the tools and data for the appraisal of the hydrocarbon generation potential and the study of the hydrocarbon formation processes，genetic mechanism and chemical kinetics. The samples used in pyrolysis experiments are usually from immature to low mature， depending on the purpose of the study and also the type of organic matter and the thermal evolution of sedimentary basins. Open system and close system are two different types of experimental apparatuses designed to probe special objectives. The open system is used to simulate primary kerogen cracking，and the closed one is used to investigate the oil and gas secondary cracking at high thermal maturation level. The effect of temperature，pressure，water and minerals on hydrocarbon generation from organic matter can be quantified through experimental simulation. As a result，the relationship between oil and gas generation history and the evolution of a sedimentary basin is revealed with the combination of the thermal history and the sedimentary history of the basin，which provides the important parameters for basin modeling. With the demand of the rapid increase in the exploration and development of shale gas and tight oil unconventional resources，in order to semi-quantitatively or quantitatively extrapolate the results of laboratory simulation to geological conditions，we outlined the following new research topics related to pyrolysis simulation from this review，including：to develop the experimental technique，especially well-constrained confining pressure for rock cylinders at high temperature and pressure condition；to further investigate hydrocarbon formation mechanism and petroleum expulsion efficiency；to enhance and strengthen high temperature and pressure simulation of organic matters，its interaction with strata water and minerals，as well as organic-inorganic interaction and their role in pore development，which will be important to the assessment of potential resources of unconventional resources，like shale gas and tight oil etc. Related Articles | Metrics Select Calculation of Strength Design of Casing Strings He Shiming 西南石油大学学报(自然科学版)    1997, 19 (1): 53-59.   DOI: 10.3863/j.issn.1000-2634.1997.01.011 Abstract （981）      PDF（pc） （303KB）（1035）       Knowledge map    Save This paper discusses the principle of triaxial stress design of casing strings, deduces the strength formula of triaxial stress, and analyzes the overall external loads applied on the casing string.The modified equal safety coefficient method is put forward on the basis of equal scatter coeffi- cient method. The new method is more reasonable than equal safety coefficient method when dealing with external loads, and it improves the design procedure. Based on the proposed method and in combination with the practice of oilfields, the software for strength design of casing string is developed and has been widely used in oilfields. Related Articles | Metrics Select Reservoir-forming Pattern of Typical Hydrocarbon Accumulation Zone inHuizhou Sag Wu Juan;Ye Jiaren;Shi Hesheng;Shu Yu;Kang Jianyun 西南石油大学学报(自然科学版)    2012, 34 (6): 17-26.   Abstract （328）      PDF（pc） （1873KB）（805）       Knowledge map    Save Based on geological，seismic and geochemical data，by means of fluid inclusion microfluorometric and thermodetecting techniques，this paper focuses on the study of reservoir-forming patterns and enrichment regulation of typical hydrocarbon accumulation zone in Huizhou Sag. The results show that oil from Wenchang source rock distributes widely in Huizhou Sag，hydrocarbon migrating vertically through faults or vertically then laterally through compound transport system，which experienced two accumulation periods，so the reservoir-forming patterns of Huixi—Liuhua accumulation zone can be divided into single source–short distance–migrated vertically–multi–phase pattern，mixed source–short distance–migrated vertically– multi–phase pattern，mixed source–short distance–migrated vertically and laterally–multi–phase pattern，single source–far distance–migrated vertically and laterally–one–phase pattern. And reservoir forming pattern of Huizhou—Lufeng accumulation zone is single source–short distance–migrated vertically–multi–phase episodic pattern. Related Articles | Metrics Select Research Progress, Challenge and Prospect of Nanoscale Oil-displacing Materials for Enhanced Oil Recovery ZHANG Chenjun, JIN Xu, YUAN Bin, ZHANG Lei, ZHENG Shaojing Journal of Southwest Petroleum University(Science & Technology Edition)    2023, 45 (1): 55-70.   DOI: 10.11885/j.issn.1674-5086.2022.04.27.03 Abstract （444）   HTML （26）    PDF（pc） （1589KB）（423）       Knowledge map    Save This review summarizes the research progress of nanoscale oil-displacing materials developed by various researchers, describes the application effect of silica nanoparticles, metal-oxide nanomaterials, polymer nanospheres and carbon nanomaterials, analyses the physical and chemical properties of existing nanoscale oil-displacing agents and their EOR mechanism in porous reservoir media, including nanometer-size effect, wettability alteration, structural disjoining pressure, mobility ratio improvement, and predicts the potential of nanoscale oil-displacing materials in high water cut reservoir, low permeability reservoirs, tight oil and shale oil in China. In addition, the review points out the challenges and research direction in the process of oilfield development, such as testing methods, accuracy of mathematical model, material versatility, economy and industrial production, and provides a theoretical and experimental basis for their large-scale application in EOR. Reference | Related Articles | Metrics Select TWO DIMENSIONAL NUMERICAL SIMULATION OF FRACTURING FLUID LEAKOFF LI Yong-ming JI Lu-jun GUO Jian-chun ZHAO Jin-zhou 西南石油大学学报(自然科学版)    2000, 22 (2): 43-45.   DOI: 10.3863/j.issn.1000-2634.2000.02.14 Abstract （829）      PDF（pc） （311KB）（969）       Knowledge map    Save Combining reservoir engineering method and numerical simulation technology, accounting for the non-Newtonian behavior of fracturing fluid and the 2 dimensional flow of filtrate during fracturing operation, a 2D dynamic leak off model of non-Newtonian fracturing fluid was established. Numerical method was employed to solve this model and the simulation results were compared to that of 1D model. It shows that, the leak off rate calculated at the consideration of that fracturing fluid leak off flows in the direction that perpendicular to the fracture face is smaller than that of 2D flow, and their difference increases with formation permeability. The 2D model is more reasonable. Because the non-Newtonian behavior of fracturing fluid and the 2D flow were accounted, this model is more applicable and its simulation results are closer to field. It can reduce the fracturing operation venture and increase the reliability of fracturing design. Related Articles | Metrics Select Annular Aerated Gas-lift Reverse Circulation Drilling Technology and Key Parameters Design LI Qian, ZHANG Xiaolin, LI Zhengtao, LI Juan, DAI Feng Journal of Southwest Petroleum University(Science & Technology Edition)    2021, 43 (4): 35-43.   DOI: 10.11885/j.issn.16745086.2021.04.29.01 Abstract （209）   HTML （5）    PDF（pc） （1736KB）（433）       Knowledge map    Save Using gas lift reverse circulation drilling technology to solve the leakage problem of Changning shale gas surface drilling, it is necessary to solve the problems of conventional gas lift reverse circulation drilling technology, such as open wellhead and inaccurate bottom hole pressure control. Therefore, on the basis of conventional gas-lift reverse circulation drilling technology, a new annular aerated gas-lift reverse circulation drilling technology is designed. The new technology is equipped with rotary blowout preventer, drill pipe cock and other tools, which has well control ability. By adjusting key construction parameters such as gas injection rate and drilling fluid displacement, bottom hole pressure is controlled to reduce drilling leakage. Based on the multiphase flow theory, the calculation model of bottom hole pressure for annular aerated gas-lift reverse circulation drilling technology is established. The influence of key construction parameters on bottom hole pressure is analyzed, and the design method of key parameters is established. The key construction parameters are optimized within the scope of safety window to ensure safe drilling. The results show that the bottom hole pressure first decreases and then rises with the increase of gas injection rate, and there is a critical gas injection rate; the bottom hole pressure rises with the increase of well depth; the bottom hole pressure rises with the increase of drilling fluid displacement. The field test was carried out in the surface drilling of a well in Changning. Compared with the lost circulation formation in the same section, the lost circulation was reduced by 83.6% using the conventional drilling technology. The research results provide a new technical measure to solve the problem of lost circulation in the surface drilling of Changning shale gas in Sichuan. Reference | Related Articles | Metrics Select Application of Fracturing Construction Curve in Fracture Evaluation of Deep Shale Gas Horizontal Wells YAN Jianping, LAI Siyu, GUO Wei, LIAO Maojie, HUANG Yi Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (5): 1-18.   DOI: 10.11885/j.issn.1674-5086.2022.10.18.04 Abstract （55）   HTML （4）    PDF（pc） （7210KB）（162）       Knowledge map    Save Shale gas horizontal wells usually do not have coring and electrical imaging scales, which makes it difficult to identify fractures. The fracturing operation curve can reflect the fracturing effect and the development of natural fractures before fracturing. Taking the deep shale gas formation of Block Y101 in Luzhou, southern Sichuan as an example, according to the type and characteristics of the fracturing operation curve in the sand-carrying fluid stage, the logging response characteristics of the fracture layer and the matrix layer before the fracturing of the horizontal well are calibrated. The wavelet transform is used to extract the high-frequency weak signal reflecting the fracture information to establish the wavelet comprehensive coefficient ( WI), the crossplot is used to select six parameter indexes sensitive to the fracture response, the analytic hierarchy process and the fuzzy mathematics method are used to construct the fracture evaluation comprehensive coefficient ( FI), and the relationship between different fracturing operation curve types and logging information is further combined to realize the identification and development level evaluation of horizontal well fracture layers. The results show that the fracturing construction curve of the sand-carrying fluid stage has a descending type (I), a descending stable type (II), a stable type (III), and an ascending type (IV). Among them, when the natural gamma high value, the compensated neutron and the density increase significantly, the acoustic time difference increases with the “jagged” cycle jump, the double lateral shows a “positive difference” and WI≥0.18， FI≥0.430, the fracturing construction curve is a descending type, and the fracture is well developed (F–A grade); When 0.390≤ FI<0.430, there are both downward type and downward stable type, and the fractures are more developed (F–B grade); when 0.350≤ FI<0.390, it is a descending stable type, and the fractures are generally developed (F–C grade). Reference | Related Articles | Metrics Select Early Intelligent Kick Warning in Well Drilling Based on Fuzzy#br# Expert System ZHANG He1*, LI Qiying1, ZHANG Luzhi2, MI Ling1 西南石油大学学报(自然科学版)    2016, 38 (2): 169-175.   DOI: 10.11885/j.issn.1674-5086.2013.12.04.05 Abstract （271）   HTML    PDF（pc） （520KB）（891）       Knowledge map    Save In well drilling process，it is difficult to establish the intelligent early kick warning model based on sample information due to the complexity of geological information or the lack of adjacent well data. Through researches on the mechanism and characteristics of the kick occuring，we suggest an exploratory well drilling intelligent early kick warning method by using drilling expert knowledge and hierarchical fuzzy expert system and develop corresponding software system. By fuzzifying parameters of kick occurring and with calculation based on fuzzy inference rule，this model is able to provide fast andaccurate early kick warning. Field test data reveals thatthe intelligent early kick warning results are good and have a good application prospect. Reference | Related Articles | Metrics Select Research of Reasonable Producing Pressure Drop of Gas CondensateReservoir on Different Period Li Qian;Li Xiangfang;Li Yanjing;Peng Yi;Cui Ligong 西南石油大学学报(自然科学版)    2012, 34 (1): 121-126.   Abstract （586）      PDF（pc） （3208KB）（767）       Knowledge map    Save During the development of gas condensate reservoir，the condensate would drop out with the fall of formation pressure. It would affect the deliverability of gas wells. However，during the depletion of gas condensate reservoir，the dropout of condensate is inevitable. We can only produce much more condensate by adjusting to reasonable working system. So，this paper researches the character of filtrate and the effect of capillary number on the production of condensate. We propose that there are two different periods of depletion of gas condensate reservoir and the determination of reasonable producing pressure drop is different in the two periods. The research results show that increasing or varying producing pressure drop can increase the deliverability of gas wells and the recovery of condensate for constant volume gas condensate reservoir. Finally，the above viewpoint is confirmed by the production performance of an actual gas condensate well. This research is of for the efficient development of gas condensate reservoir. Related Articles | Metrics Select The New Calculation Method of Condensate Gas Well Production andReservoirs Liao Faming;Miao Jijun;Chen Wenlong;Deng Jun;Wang Nutao 西南石油大学学报(自然科学版)    2012, 34 (4): 100-104.   Abstract （497）      PDF（pc） （492KB）（703）       Knowledge map    Save Complex phase change and re-distribution exist in gas condensate reservoir. It will produce gas condensate in formation and the wellbore，respectively，when the pressure drop to below dew point pressure，resulting in the conversion of mass between wellhead and bottom hole in gas production and oil production，but still follows the law of conservation of total mass. Therefore，according to mass conservation principle，we established the oil and gas two-phase flow equations. By introducing the two-phase pseudo-pressure function，unstable deliverability equation was derived. On this basis，we fit the entire history of production by taking material balance equation and production data into consideration. With this method we not only get the current gas production，but a variety of formation pressure and formation parameters. An example is then analyzed to verify the accuracy and reliability，the method is conducive to the promotion the use of gas condensate. Related Articles | Metrics Select Current Situation, Challenges and Countermeasures of China's Energy Transformation and Energy Security Under the Goal of Carbon Neutrality HOU Meifang Journal of Southwest Petroleum University(Science & Technology Edition)    2023, 45 (2): 1-10.   DOI: 10.11885/j.issn.1674-5086.2023.01.12.02 Abstract （516）   HTML （55）    PDF（pc） （1295KB）（567）       Knowledge map    Save Human society is now in its third stage of energy transformation, with the goal of carbon neutrality and sustainable development, after the first two major energy transformation periods. China's energy development is facing complex situation and severe challenges under the new situation. We must accelerate the low-carbon energy transformation to achieve carbon neutrality, and firmly safeguard the bottom line of energy security at the same time. It is a major issue for China's high-quality energy development to balance energy transformation and energy security. Studies indicate that: 1) the previous two energy transformations were both in line with the traditional law of economic development and accompanied by the industrial revolution. In these two transformations, energy acted as common productive factors, and the energy structure gradually changed under the drive of technology. However, the core reasons of the third energy transformation are to address climate change and guarantee energy security. The ongoing transformation is driven by the strategic measures of sustainable development besides technological development, and it requires multiple efforts. 2) there are lots of risks in China's energy transformation: the total energy consumption is too large, the carbon emission and proportion of coal in energy structure is too high, the domestic production of oil and gas is too low, the dependence ration of overseas oil and gas is too high, and the development of renewable energy is too weak. 3) under the goal of carbon neutrality, China's energy transformation and energy security should focus on "three acceleration": making full use of the advantages of socialist system, speeding up the construction of new energy system through the way of cleaning fossil energy, scaling up renewable energy and developing smart comprehensive energy, speeding up independent innovation of science and technology in the fields of coal, oil, gas and renewable energy, speeding up the implementation of energy conservation. Reference | Related Articles | Metrics Select Organic Volume Proportion in Shale: Concept, Measurement Method and Significance YOU Lijun, FAN Daoquan, KANG Yili, ZHOU Yang, CHEN Yang Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (2): 1-14.   DOI: 10.11885/j.issn.1674-5086.2022.07.15.03 Abstract （213）   HTML （219）    PDF（pc） （2473KB）（155）       Knowledge map    Save Total Organic Content is an essential index for evaluating the oil and gas production capacity of shale, which has an impact on porosity and gas content and is also a key parameter for evaluating the ``geological sweet spot" of shale reservoir. However, TOC cannot reflect the distribution, connectivity, spatial proportion of organic matter and its influence on oil and gas flow and reservoir transformation. Through data sorting and analysis, the concept of Organic Volume Proportion was clarified and gave and analyzed the advantages and disadvantages of five calculation methods, including the formula method, scanning electron microscopy estimation method, CT scanning method, low-field NMR measurement method, and rock physics model method. The significance of organic matter volume content to developing organic-rich shale oil and gas is also discussed. The Organic Volume Proportion refers to the volume of organic matter per unit volume of shale. It is expressed as a percentage, which strengthens the importance of organic pores in shale gas reservoir evaluation and development, and enriches the evaluation parameter system of shale oil and gas reservoirs. Organic matter is the weak structural point or weak structural plane of shale, the characteristics of OVP bridge the geological sweet spot and engineering sweet spot indicators, the solubility and spatial proportion of organic matter lay the foundation for the new idea of ``removal material and increment permeability" in oil and gas reservoirs. When organic matter is taken as the object of dissolution, a small amount of organic matter dissolution will greatly increase the reservoir reconstruction volume. Reference | Related Articles | Metrics Select STREATHEN GAS INJECTION FOR ENHANCED OIL RE COVERY Li Shi-lun Guo Ping DaiLei Sun Lei 西南石油大学学报(自然科学版)    2000, 22 (3): 41-45.   DOI: 10.3863/j.issn.1000-2634.2000.03.011 Abstract （1611）      PDF（pc） （176KB）（1162）       Knowledge map    Save Enhance Oil Recovery (EOR)is one of the permanent top-ics in research on Oil/gas reservoir development. Because of low oil price, the demand for chemical drive is keeping decreasing and for gas drives increasing. The reservoirs in East China oil fields are non-marine deposits with Serious heterogeneity and high viscosity crudes, Water Cut increases very fast, recovery by water drive is relatively low, only 33%.The reserve discov- ered recently is difficult to produce because of low permeability of the reservoirs and high viscosity of the crudes, streathening gas injection for enhanced oil recovery has become an urgent strategy in on shore petroleum industry development. China launched the evaluation in the second time on tertiary recovery potential in 1998.By statistics, the geological reserve suitable for gas injection(CO2) miscible flooding is over 10.57×108 tons. By combination of foreign experience and the analysis and evaluation on China’s tertiary recovery potential, it is recog-nized that the oil fields in east china oil- bearing provinces should streathen non-gas drive and the oil field in west china should be hydrocarbon drive dominant. The key to gas drive is gas resource, the discovery of CO2resource should be placed at-tention to, and the technology to generate N2and CO2, inject and sperate N2should be probed. The development of compres-sion facility-home made, pilot tests of gas drive and dry gas recycle for gas condensate reservoir with rich condensates should be speeded up. Related Articles | Metrics Select STUDY ON THE DETERMINATION OF PRODUCTIVI TY INDEX AND FORMATION PRESSURE OF OIL WELLS LI Chuan-liang KONG Xiang-yan 西南石油大学学报(自然科学版)    2000, 22 (2): 40-42.   DOI: 10.3863/j.issn.1000-2634.2000.02.13 Abstract （842）      PDF（pc） （303KB）（923）       Knowledge map    Save In order to use well test information correctly, a theoretical study was conducted on the determination of productivity index(PI) and formation pressure from IPR curves. For pressure maintaining reservoir, because the external boundary pressure (Pe) keeps constant and the average pressure is a variable over the drainage area of the well, only Peand the productivity index Jo(Pe) of an oil well defined by Pecan be obtained from IPR curve. For depleting reservoir, because Peis a variable and the average pressure over the drainage are a keeps constant, only and the productivity index Jo(P) of an oil well defined by can be obtained from IPR curve. Related Articles | Metrics Select Geometric Design of Involute Standard Spur Gears Yang Yi-ming Zhang Hong-rong 西南石油大学学报(自然科学版)    1996, 18 (3): 102-105.   DOI: 10.3863/j.issn.1000-2634.1996.03.016 Abstract （871）      PDF（pc） （325KB）（1084）       Knowledge map    Save Basing on the ongaging theory of involute standard spur gears,this paper descriobesthe parameters and tooth profiles,and the way of determining the technical parameters ge-ometric dimension. Related Articles | Metrics Select Review on the Characteristics of Pyrolysis During In-situ Conversion of Oil Shale XU Jinze, CHEN Zhangxing, ZHOU Desheng, NIE Wancai, LI Ran Journal of Southwest Petroleum University(Science & Technology Edition)    2021, 43 (5): 220-226.   DOI: 10.11885/j.issn.1674-5086.2021.02.28.03 Abstract （420）   HTML （18）    PDF（pc） （1601KB）（447）       Knowledge map    Save Recently, the consumption of global energy gradually increases, and the oil shale is an important substitution for the conventional oil and gas. The oil shale reserves in China are abundant, which ranks the fourth in the world. As the main technology to develop oil shale reservoirs, the in-situ conversion utilizes pyrolysis to expand seepage pathways to obtain shale oil and gas. This paper reviews the characteristics of pyrolysis from four aspects:the stage of pyrolysis, the pyrolysis of kerogen, the impact of minerals and the evolution of pore structures assisted by pyrolysis:(1) thermophysical evolution and thermochemical reactions in different stages of pyrolysis reaction; (2) reaction mechanism of kerogen pyrolysis and its influencing factors; (3) promoting and inhibiting effects of mineral decomposition on pyrolysis; (4) the mechanism of pore structure evolution assisted by pyrolysis and its effects on fracture propagation. This paper is based on the pyrolysis which is the core technical challenge during the in-situ conversion. It will also provide some references for the application of in-situ conversion in oil shale and shale oil with low and medium maturities. Reference | Related Articles | Metrics Select CORRECT UNDERSTANDING OF TWE PIPE-STRING NEUTRAL POINT Wu Jiang 西南石油大学学报(自然科学版)    1988, 10 (2): 29-38.   DOI: 10.3863/j.issn.1000-2634.1988.02.04 Abstract （1257）      PDF（pc） （611KB）（694）       Knowledge map    Save In this article, all definitions of pipe-string neutral point mentioned in previous occasions and their mechanical properties are analyzed in detail. The relationship between the neutral point, the axial zero-stress point and the neutral section is discussed. Answers are presented to such problems as whether the neutral point is the unstable demarcation point of the pipe-string while bent. This is beneficial to the correct understanding of the neutral point and its effect on engineering. Related Articles | Metrics Select Diagenetic-pore Quantitative Evolution of the Reservoir from Lower Huagang Formation in the South-central Xihu Sag ZHAO Xiaoming, DAI Maolin, LIU Shu, GE Jiawang, ZHAO Tianpei Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (1): 21-34.   DOI: 10.11885/j.issn.1674-5086.2022.07.01.03 Abstract （136）   HTML （12）    PDF（pc） （31265KB）（149）       Knowledge map    Save The Lower Huagang Formation in Xihu Sag is rich in tight gas resources, which is a hot spot for oil and gas exploration and development in this area. Based on observation of rock slices, scanning electron microscopy, physical property testing of the core and X-ray diffraction, the basic reservoir characteristics, the diagenesis and the pore evolution of the reservoir are studied. The results show the reservior porosity is mainly between 7% and 10%, the permeability mainly between 0.10 to 0.50 mD, and the fracture undeveloped, so the reservoir belongs to a kind of tight sandstone reservoir. The reservoir has experienced the early diagenesis stage A and B and the middle diagenetic stage A, and is currently in the middle diagenesis stage B, and the reservoir are greatly influenced by compaction, dissolution and cementation. The results of pore quantitative evolution show that the compaction reduces porosity by 29.67%, which is the main reason for the undeveloped primary pores; the dissolution increases porosity by 15.14%, which is the key factor for the development of deep reservoirs; with the influence of cementation, the reservoir porosity reduces by 13.55%, which is an important reason for the deterioration of reservoir pore structure. Based on the relationship between pore evolution results and oil-gas charging time, the Lower Huagang Formation in the south-central of the Xihu Sag is a kind of tight reservoir that denses before the accumulation of oil and gas. Reference | Related Articles | Metrics Select CASING COLLAPSE RESISTANCE ANALYSIS AND CALCULATION SHEN Zhao-xi;FENG Yao-rong;XIE Xue-dong;YANG Peng 西南石油大学学报(自然科学版)    2008, 30 (3): 139-142.   DOI: 10.3863/j.issn.1000-2634.2008.03.036 Abstract （1488）      PDF（pc） （486KB）（914）       Knowledge map    Save To improve the precision of casing collapse pressure calculation,the variance analysis of the full scale collapse test data of 213 casings is conducted with statistical method.The effects of outer diameter/wall thickness,material yield strength,ovality,eccentricity and residual stress on the casing collapse resistance are analyzed in this paper.The results show the ratio of diameter and thickness and yield strength are the main parameters of influencing the collapse pressure of casing,and the decreasing of the casing collapse resistance is a random process with the increasing of ovality,eccentricity and residual stress.And the casing simulation analysis of various combinations of the location of ovality,eccentricity and residual stress under external pressure is performed.From the simulation results,it is concluded that the casing collapse pressures differs greatly between different combinations.In the end,a new casing collapse calculating formula is put forward which gives the more accurate prediction of casing collapse,the accuracy can meet the requirement of application. Related Articles | Metrics Select The Adsorption and Desorption of Coal Bed Methane: A Review ZHU Suyang, DU Zhimin, LI Chuanliang, PENG Xiaolong, WANG Chaowen 西南石油大学学报(自然科学版)    2017, 39 (4): 104-112.   DOI: 10.11885/j.issn.16745086.2015.11.12.05 Abstract （292）   HTML    PDF（pc） （2437KB）（1150）       Knowledge map    Save In this study, we investigated progress in the following three aspects of coal bed methane(CBM) research:adsorption theory and experiments, the effects of water on adsorption and desorption, and liquid-solid adsorption theory. We summarized the achievements of gas phase adsorption theory in studying CBM adsorption, and, in particular, the influence of water. In addition, existing complications in gas phase adsorption theory with regards to CBM adsorption were analyzed, and the new liquid phase adsorption theory and CBM compound desorption model built on its basis were introduced. Different water phases have a variable impact on CBM adsorption. When water saturation is low in the coal sample, equilibrium moisture in the gas phase can significantly reduce the amount of CBM adsorbed. As water saturation reaches critical levels, water content has little effect on the amount of CBM adsorbed. Upon further increase in water content in the coal sample, liquid-state water in the injected coal sample increases the quantity of CBM adsorbed. The occurrence of CBM is not in agreement with the existing gas phase adsorption model. In contrast, the liquid phase adsorption model explains both the hydrocarbon generation condition of coal in an aqueous environment and the absence of critical desorption pressure in gas phase adsorption. Under the conditions of liquid phase adsorption, the desorption of CBM is a compound desorption process controlled by both gas phase and liquid phase desorption. Reference | Related Articles | Metrics Select Optimization of Injection Technique of Corrosion Inhibitor in CO 2-flooding Oil Recovery ZHANG Deping, MA Feng, WU Yule, DONG Zehua 西南石油大学学报(自然科学版)    2020, 42 (2): 103-109.   DOI: 10.11885/j.issn.1674-5086.2019.05.08.01 Abstract （188）   HTML    PDF（pc） （767KB）（1142）       Knowledge map    Save Severe downhole corrosion occurred during Jilin CO 2 flooding in an oilfield in Jilin due to the high pressure of CO 2, high concentration of saline water and sulfate reducing bacteria (SRB) in the produced fluid. Currently, addition of corrosion inhibitors is one of the common methods to protect the oil well and tubes. Through studies of corrosion mechanism and main factor analysis, the effects of inhibitor type, concentration, and injection technique on their filed inhibition efficiency and long-term durability were investigated, aiming at lowering the cost of corrosion management. Then a suitable injection regulation of inhibitor is proposed based on the filed situation in order to improve the long-term efficacy of inhibitor. Injection optimization tests indicate that the corrosion rate has been decreased to <0.076 mm/a. This optimized injection technique of inhibitor not only increases the service life of downhole device and tubes but also decrease the cost of corrosion management. Reference | Related Articles | Metrics Select Techniques of Natural Diamond Bit CAD Yang Ying-xin Hou Ji-kang Lin Yu-long Xiao Yu-ping 西南石油大学学报(自然科学版)    1997, 19 (2): 59-62.   DOI: 10.3863/j.issn.1000-2634.1997.02.13 Abstract （799）      PDF（pc） （168KB）（928）       Knowledge map    Save A set of practical soft wares about natural diamond bit design was developed by applying the techniques of Computer Aided Design (CAD). The use of these soft wares makes bit design more scientific and more effective. This paper describes the principle and content of these soft wares. Related Articles | Metrics Select nfluence of Stearic Acid on Paraffin Melting Point and It′s Mechanical Properties WANG Ling et al 西南石油大学学报(自然科学版)    2008, 30 (2): 112-115.   Abstract （1759）      PDF（pc） （260KB）（1027）       Knowledge map    Save In order to provide a scientific basis for improving paraffin properties and its application, the digital instrument of melting point and universal material machine are used to study the melting point and strength of the paraffin-stearic acid system. The mechanism is also discussed with infrared spectroscopy. The result of experiment indicates stearic acid has some effect on paraffin melting point. When the content of stearic acid is lower than 40 wt %, the melting point of paraffin decreases with the increase of stearic acid addition, however, when the content of stearic acid is in the range of 40 wt% to 100wt%, the melting point increases, stearic acid has positive effect on strength of paraffin, especially, when the content of stearic acid is in the range of 0 to 10wt%, the strength of paraffin increases rapidly, and the strength growth rate reaches 32.56%, the reason is that the stearic acid wipes out the bubble in paraffin and the paraffin becomes more uniform. According to infrared spectroscopy, there is a lot of resemblance between paraffin and stearic acid, so they can fuse together at any proportion; in industrial application, less than 20 wt% stearic acid should be reasonable in order to increase the strength but not decrease the melting point too much. Related Articles | Metrics Select Modeling of the Reservoir Architecture of Thin Interbedded Deposits MOU Zhonghai, LIU Xue, CHANG Lin, SU Qiu, WU Qianran 西南石油大学学报(自然科学版)    2020, 42 (3): 1-12.   DOI: 10.11885/j.issn.1674-5086.2018.11.21.06 Abstract （251）   HTML    PDF（pc） （28644KB）（1988）       Knowledge map    Save Taking the braided river deltas of the Q6 Block in the Kunbei Oilfield in the Qaidam Basin as an example, this study investigated methods to model the architecture of thin interbedded reservoir sandstones. Traditional methods are based on the relatively maximum values of natural gamma measurements and (or) positive spontaneous potential abnormalities to determine the boundaries of sub-layers. Meanwhile, the sub-layer division based on the tangent points of reflected and diffracted wavefronts can more accurately depict the thickness and depth of reservoir layers, insulating layers, and interlayers. The interlayers in the study area are dominated by localized mudstones. Hence, two parameters, the thickness of low-permeability layers and permeability return level, were adopted to identify the interlayers. This enhanced the model accuracy. Because the braided river deltas were under the hydrodynamic control of both river and lake waves and the strata are characterized by thin interbedded low-inclination sand-mudstones, this study proposes that strict data control, hierarchical modeling and reservoir layer/interlayer nesting should be included to construct an architectural model of the thin interbedded deposits. Subsequently, an architectural model for the braided river deltas of the Q6 Block in the Kunbei region was established. Analysis of the relationships between the architectural units of the model shows that there are four types of architecture in the target layers. They are lateral stitching, lateral separation, progradation, and accretion. Among them, the lateral stitching and vertical accretion modes of the sand bodies are the most developed. Compared to the traditional modeling method, the proposed method is more advantageous and sensible for thin interbedded deposits. Reference | Related Articles | Metrics Select Researches on Relationship Between Production Allocation and Decline Rate of Gas Wells in Sulige Gas Field LI Peng, FAN Qianqian, HUO Minghui, ZHENG Lanian, YUE Jun 西南石油大学学报(自然科学版)    2020, 42 (1): 126-132.   DOI: 10.11885/j.issn.1674-5086.2018.12.07.01 Abstract （188）   HTML    PDF（pc） （566KB）（1016）       Knowledge map    Save To determine the rational production allocation for gas wells with a certain initial decline rate, Arps decline curve analysis was used to clarify the positive proportionality between new well production allocation and its initial daily decline rate, assuming that the initial production allocation of the gas wells is not affected by their final cumulative gas production. The initial daily decline rate was then converted into the initial annual decline rate to determine the relationship between the gas well production allocation and the initial annual decline rate, and a theoretical chart was established for the degrees of reduction in gas well production and in the initial annual decline rate, which can be used to guide the rational production allocation of new gas wells and determine the workload for gas field capacity building. This study demonstrated that, in reducing production allocation to reduce gas well decline, the magnitude of reduction in gas well decline rate is related to the magnitude of the initial annual decline rate and the magnitude of the reduction in production allocation, rather than the absolute value of the reduction in production allocation. The larger the initial annual decline of the gas wells, the more significant is the reduction in gas well decline through reduction of production allocation. The opposite is observed for gas wells with relatively small initial annual decline, whose reduction decline is not significant through reduction of production allocation. Reference | Related Articles | Metrics Select Ground Stress Field Inversion and Fracture Prediction Based on MLR-ANN Algorithm ZHANG Bohu, HU Yao, WANG Yan, CHEN Wei, LUO Chao Journal of Southwest Petroleum University(Science & Technology Edition)    2024, 46 (3): 1-12.   DOI: 10.11885/j.issn.1674-5086.2022.08.20.01 Abstract （110）   HTML （15）    PDF（pc） （3743KB）（142）       Knowledge map    Save Shale gas reservoirs are deeply buried in China, and the distribution law of ground stress is complex due to tectonic movement. It is difficult for traditional methods to reflect the magnitude and direction distribution of regional in-situ stress accurately. A coupling algorithm of multiple linear regression and artificial neural network is proposed to invert the shale gas reservoir and surrounding ground stress in Changning-Jianwu Block, southern Sichuan. Using the comprehensive fracture coefficient method, the reservoir fractures are predicted and the fracture development areas are divided. The in-situ stress in the study area is mainly compressive stress, and the direction is about NE115°. The stress around the fault caused by tectonic movement is relatively concentrated, and shear cracks are easy to develop. The cracks are mainly developed and medium developed. The study area has a high degree of fracture development in the upper part of the Wufeng Formation and the structural fault near the bottom of the Longmaxi Formation. The research results have important reference value for well pattern arrangement, fracturing optimization design and casing damage prevention of shale gas extraction. Reference | Related Articles | Metrics