The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Chao Li - One of the best experts on this subject based on the ideXlab platform.
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in situ stress state in the linxing region eastern ordos basin china implications for unconventional gas exploration and production
Marine and Petroleum Geology, 2017Co-Authors: Wei Ju, Shangzhi Meng, Caifang Wu, Yulin Shen, Guozhang Li, Zhaobiao Yang, Jian Shen, Chao LiAbstract:Abstract The Carboniferous and Permian sedimentary rocks (mainly the Shanxi and Taiyuan formations) in the Linxing region, eastern Ordos Basin, China, host a significant volume of unconventional gas resources (coalbed methane, shale gas and tight sandstone gas). Currently, the in-situ stress state is poorly understood but knowledge of this is extremely important for a range of applications, such as gas exploration and production, fracture stimulation and wellbore stability. The maximum horizontal stress ( S Hmax ), minimum horizontal stress ( S hmin ) and vertical stress ( S v ) magnitudes, and the S Hmax orientation in the Linxing region were systematically analyzed for the first time in the present study, which can provide a reference for subsequent numerical simulation and Hydraulic Fracturing Design. Based on borehole breakouts and drilling-induced tensile fractures interpreted from borehole imaging logs, the S Hmax orientation rotates from ∼NEE-SWW-trending in the southern part to ∼ NWW-SEE-trending in the northern part of the Linxing region. Both conventional logs and extended leak-off tests were used for stress magnitude determination. The results revealed three types of in-situ stress fields ( S v > S Hmax > S hmin , S Hmax > S v > S hmin and S Hmax > S v ≈ S hmin ), and a dominant strike-slip stress regime ( S Hmax > S v ≥ S hmin ) was found for the entire well section in the target Shanxi Formation and Taiyuan Formation in the Linxing region. In addition, differential stress increased with depth in the Linxing region, which indicates that wellbore instability might be a potentially significant problem when drilling wells that are vertical or ∼ N-S-trending.
Wei Ju - One of the best experts on this subject based on the ideXlab platform.
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characteristics of in situ stress state and prediction of the permeability in the upper permian coalbed methane reservoir western guizhou region sw china
Journal of Petroleum Science and Engineering, 2018Co-Authors: Wei Ju, Tongsheng Yi, Zhaobiao Yang, Zhengguang ZhangAbstract:Abstract Coal permeability and in-situ stress state are important parameters for coalbed methane (CBM) exploration and development; however, the distribution pattern of the Upper Permian CBM reservoir permeability is poorly understood in the western Guizhou region, SW China. In the present study, based on measured injection/falloff and in-situ stress data in the Upper Permian coal seams of western Guizhou region, the present-day in-situ stress field, and its correlation with coal permeability were investigated. The orientation of the horizontal maximum principal stress (SHmax) indicated a dominant ∼ NW-SE-trending. In addition, the present-day in-situ stress field showed an important control on coal permeability. The permeability in the Upper Permian coal seams decreased exponentially with the increased effective in-situ stress magnitude. By utilizing the finite element method (FEM), the present-day in-situ stress field in the western Guizhou was numerically analyzed based on a geomechanical two-dimensional (2D) model. Distribution of coal permeability in the Upper Permian CBM reservoir was predicted based on the relationship between coal permeability and effective in-situ stress magnitude. The results indicated that, in the western Guizhou region, vertically, coal permeability was relatively high and widely distributed shallower than approximately 780 m below ground level (bgl), whereas, it was extremely low and regularly varied with burial depth deeper than approximately 780 m bgl. Laterally, the distribution pattern of coal permeability was characterized by strong heterogeneity due to well-developed faults and folds. High values of the Upper Permian coal permeability were located in regions around Nayong-Zhijin, Panxian-Anlong and along Shuicheng-Liuzhi-Ziyun. The present study may provide geological references for the CBM reservoir productivity and subsequent analysis (e.g., wellbore stability, Hydraulic Fracturing Design, and fault reactivation studies, etc.) in the western Guizhou region.
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in situ stress state in the linxing region eastern ordos basin china implications for unconventional gas exploration and production
Marine and Petroleum Geology, 2017Co-Authors: Wei Ju, Shangzhi Meng, Caifang Wu, Yulin Shen, Guozhang Li, Zhaobiao Yang, Jian Shen, Chao LiAbstract:Abstract The Carboniferous and Permian sedimentary rocks (mainly the Shanxi and Taiyuan formations) in the Linxing region, eastern Ordos Basin, China, host a significant volume of unconventional gas resources (coalbed methane, shale gas and tight sandstone gas). Currently, the in-situ stress state is poorly understood but knowledge of this is extremely important for a range of applications, such as gas exploration and production, fracture stimulation and wellbore stability. The maximum horizontal stress ( S Hmax ), minimum horizontal stress ( S hmin ) and vertical stress ( S v ) magnitudes, and the S Hmax orientation in the Linxing region were systematically analyzed for the first time in the present study, which can provide a reference for subsequent numerical simulation and Hydraulic Fracturing Design. Based on borehole breakouts and drilling-induced tensile fractures interpreted from borehole imaging logs, the S Hmax orientation rotates from ∼NEE-SWW-trending in the southern part to ∼ NWW-SEE-trending in the northern part of the Linxing region. Both conventional logs and extended leak-off tests were used for stress magnitude determination. The results revealed three types of in-situ stress fields ( S v > S Hmax > S hmin , S Hmax > S v > S hmin and S Hmax > S v ≈ S hmin ), and a dominant strike-slip stress regime ( S Hmax > S v ≥ S hmin ) was found for the entire well section in the target Shanxi Formation and Taiyuan Formation in the Linxing region. In addition, differential stress increased with depth in the Linxing region, which indicates that wellbore instability might be a potentially significant problem when drilling wells that are vertical or ∼ N-S-trending.
Zhaobiao Yang - One of the best experts on this subject based on the ideXlab platform.
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characteristics of in situ stress state and prediction of the permeability in the upper permian coalbed methane reservoir western guizhou region sw china
Journal of Petroleum Science and Engineering, 2018Co-Authors: Wei Ju, Tongsheng Yi, Zhaobiao Yang, Zhengguang ZhangAbstract:Abstract Coal permeability and in-situ stress state are important parameters for coalbed methane (CBM) exploration and development; however, the distribution pattern of the Upper Permian CBM reservoir permeability is poorly understood in the western Guizhou region, SW China. In the present study, based on measured injection/falloff and in-situ stress data in the Upper Permian coal seams of western Guizhou region, the present-day in-situ stress field, and its correlation with coal permeability were investigated. The orientation of the horizontal maximum principal stress (SHmax) indicated a dominant ∼ NW-SE-trending. In addition, the present-day in-situ stress field showed an important control on coal permeability. The permeability in the Upper Permian coal seams decreased exponentially with the increased effective in-situ stress magnitude. By utilizing the finite element method (FEM), the present-day in-situ stress field in the western Guizhou was numerically analyzed based on a geomechanical two-dimensional (2D) model. Distribution of coal permeability in the Upper Permian CBM reservoir was predicted based on the relationship between coal permeability and effective in-situ stress magnitude. The results indicated that, in the western Guizhou region, vertically, coal permeability was relatively high and widely distributed shallower than approximately 780 m below ground level (bgl), whereas, it was extremely low and regularly varied with burial depth deeper than approximately 780 m bgl. Laterally, the distribution pattern of coal permeability was characterized by strong heterogeneity due to well-developed faults and folds. High values of the Upper Permian coal permeability were located in regions around Nayong-Zhijin, Panxian-Anlong and along Shuicheng-Liuzhi-Ziyun. The present study may provide geological references for the CBM reservoir productivity and subsequent analysis (e.g., wellbore stability, Hydraulic Fracturing Design, and fault reactivation studies, etc.) in the western Guizhou region.
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in situ stress state in the linxing region eastern ordos basin china implications for unconventional gas exploration and production
Marine and Petroleum Geology, 2017Co-Authors: Wei Ju, Shangzhi Meng, Caifang Wu, Yulin Shen, Guozhang Li, Zhaobiao Yang, Jian Shen, Chao LiAbstract:Abstract The Carboniferous and Permian sedimentary rocks (mainly the Shanxi and Taiyuan formations) in the Linxing region, eastern Ordos Basin, China, host a significant volume of unconventional gas resources (coalbed methane, shale gas and tight sandstone gas). Currently, the in-situ stress state is poorly understood but knowledge of this is extremely important for a range of applications, such as gas exploration and production, fracture stimulation and wellbore stability. The maximum horizontal stress ( S Hmax ), minimum horizontal stress ( S hmin ) and vertical stress ( S v ) magnitudes, and the S Hmax orientation in the Linxing region were systematically analyzed for the first time in the present study, which can provide a reference for subsequent numerical simulation and Hydraulic Fracturing Design. Based on borehole breakouts and drilling-induced tensile fractures interpreted from borehole imaging logs, the S Hmax orientation rotates from ∼NEE-SWW-trending in the southern part to ∼ NWW-SEE-trending in the northern part of the Linxing region. Both conventional logs and extended leak-off tests were used for stress magnitude determination. The results revealed three types of in-situ stress fields ( S v > S Hmax > S hmin , S Hmax > S v > S hmin and S Hmax > S v ≈ S hmin ), and a dominant strike-slip stress regime ( S Hmax > S v ≥ S hmin ) was found for the entire well section in the target Shanxi Formation and Taiyuan Formation in the Linxing region. In addition, differential stress increased with depth in the Linxing region, which indicates that wellbore instability might be a potentially significant problem when drilling wells that are vertical or ∼ N-S-trending.
Azra N. Tutuncu - One of the best experts on this subject based on the ideXlab platform.
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Hydraulic Fracturing and Production Optimization in Eagle Ford Shale Using Coupled Geomechanics and Fluid Flow Model
Rock Mechanics and Rock Engineering, 2017Co-Authors: Theerapat Suppachoknirun, Azra N. TutuncuAbstract:With increasing production from shale gas and tight oil reservoirs, horizontal drilling and multistage Hydraulic Fracturing processes have become a routine procedure in unconventional field development efforts. Natural fractures play a critical role in Hydraulic fracture growth, subsequently affecting stimulated reservoir volume and the production efficiency. Moreover, the existing fractures can also contribute to the pressure-dependent fluid leak-off during the operations. Hence, a reliable identification of the discrete fracture network covering the zone of interest prior to the Hydraulic Fracturing Design needs to be incorporated into the Hydraulic Fracturing and reservoir simulations for realistic representation of the in situ reservoir conditions. In this research study, an integrated 3-D fracture and fluid flow model have been developed using a new approach to simulate the fluid flow and deliver reliable production forecasting in naturally fractured and Hydraulically stimulated tight reservoirs. The model was created with three key modules. A complex 3-D discrete fracture network model introduces realistic natural fracture geometry with the associated fractured reservoir characteristics. A Hydraulic Fracturing model is created utilizing the discrete fracture network for simulation of the Hydraulic fracture and flow in the complex discrete fracture network. Finally, a reservoir model with the production grid system is used allowing the user to efficiently perform the fluid flow simulation in tight formations with complex fracture networks. The complex discrete natural fracture model, the integrated discrete fracture model for the Hydraulic Fracturing, the fluid flow model, and the input dataset have been validated against microseismic fracture mapping and commingled production data obtained from a well pad with three horizontal production wells located in the Eagle Ford oil window in south Texas. Two other Fracturing geometries were also evaluated to optimize the cumulative production and for the three wells individually. Significant reduction in the production rate in early production times is anticipated in tight reservoirs regardless of the Fracturing techniques implemented. The simulations conducted using the alternating Fracturing technique led to more oil production than when zipper Fracturing was used for a 20-year production period. Yet, due to the decline experienced, the differences in cumulative production get smaller, and the alternating Fracturing is not practically implementable while field application of zipper Fracturing technique is more practical and widely used.
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Coupled Geomechanics and Fluid Flow Model for Production Optimization in Naturally Fractured Shale Reservoirs
Seg Technical Program Expanded Abstracts, 2015Co-Authors: Jennifer S. Curnow, Azra N. TutuncuAbstract:The benefits of Hydraulic Fracturing horizontal wells in unconventional reservoirs for production enhancement are evident; however, the best methods to truly increase recovery efficiency through these stimulations are still under great examination. Analogous to how operators and service companies discovered that Barnett-style slickwater treatments were not successful in all reservoirs, companies are beginning to recognize the importance of engineered stimulations, specifically in regard to geomechanics. Rather than perforating for only production purposes, Hydraulic Fracturing Design has now turned its focus to perforating for reservoir rock stimulation. Enhanced fracture network complexity through induced fractures greatly increases the contact area and reservoir drainage for maximum productivity. However, to accomplish the stimulation of both primary and secondary fracture networks, the coupled behaviors of geomechanics and fluid flow in response to the Hydraulic Fracturing operations must be considered. This paper details the development of a coupled geomechanics and fluid flow model for the purpose of Hydraulic fracture Design optimization through the evaluation of different stimulation patterns. The patterns under consideration include the Zipper, Texas Two-Step, and Modified Zipper Designs. Furthermore within these patterns, the well locations and Hydraulic fracture properties are analyzed to determine the most ideal Design for a shale oil reservoir based on recovery efficiency and generated fracture complexity.
Jian Shen - One of the best experts on this subject based on the ideXlab platform.
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in situ stress state in the linxing region eastern ordos basin china implications for unconventional gas exploration and production
Marine and Petroleum Geology, 2017Co-Authors: Wei Ju, Shangzhi Meng, Caifang Wu, Yulin Shen, Guozhang Li, Zhaobiao Yang, Jian Shen, Chao LiAbstract:Abstract The Carboniferous and Permian sedimentary rocks (mainly the Shanxi and Taiyuan formations) in the Linxing region, eastern Ordos Basin, China, host a significant volume of unconventional gas resources (coalbed methane, shale gas and tight sandstone gas). Currently, the in-situ stress state is poorly understood but knowledge of this is extremely important for a range of applications, such as gas exploration and production, fracture stimulation and wellbore stability. The maximum horizontal stress ( S Hmax ), minimum horizontal stress ( S hmin ) and vertical stress ( S v ) magnitudes, and the S Hmax orientation in the Linxing region were systematically analyzed for the first time in the present study, which can provide a reference for subsequent numerical simulation and Hydraulic Fracturing Design. Based on borehole breakouts and drilling-induced tensile fractures interpreted from borehole imaging logs, the S Hmax orientation rotates from ∼NEE-SWW-trending in the southern part to ∼ NWW-SEE-trending in the northern part of the Linxing region. Both conventional logs and extended leak-off tests were used for stress magnitude determination. The results revealed three types of in-situ stress fields ( S v > S Hmax > S hmin , S Hmax > S v > S hmin and S Hmax > S v ≈ S hmin ), and a dominant strike-slip stress regime ( S Hmax > S v ≥ S hmin ) was found for the entire well section in the target Shanxi Formation and Taiyuan Formation in the Linxing region. In addition, differential stress increased with depth in the Linxing region, which indicates that wellbore instability might be a potentially significant problem when drilling wells that are vertical or ∼ N-S-trending.
