Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments

The southeastern Sichuan region is characterized by complex tectonic structures. The shale gas reservoir from the first member of the upper Ordovician Wufeng Formation to the Lower Silurian Longmaxi Formation is buried at considerable depths, which significantly affects the rock mechanical propertie...

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Main Author: FENG Shaoke, XIONG Liang
Format: Article
Language:zho
Published: Editorial Department of Petroleum Reservoir Evaluation and Development 2025-06-01
Series:Youqicang pingjia yu kaifa
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Online Access:https://red.magtech.org.cn/fileup/2095-1426/PDF/1748402865920-1998114405.pdf
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author FENG Shaoke, XIONG Liang
author_facet FENG Shaoke, XIONG Liang
author_sort FENG Shaoke, XIONG Liang
collection DOAJ
description The southeastern Sichuan region is characterized by complex tectonic structures. The shale gas reservoir from the first member of the upper Ordovician Wufeng Formation to the Lower Silurian Longmaxi Formation is buried at considerable depths, which significantly affects the rock mechanical properties. However, systematic studies remain limited. This study focuses on the deep shale gas reservoir in the Lintanchang area of southeastern Sichuan. A series of mechanical experiments, including triaxial compressive tests, acoustic wave velocity measurements, tensile strength tests, and fracture toughness tests, were carried out. Based on the results of these multi-mechanical experiments, the rock mechanical properties of shale samples were analyzed, and a vertical mechanical property profile for a single well was established. With increasing temperature and pressure, the residual stress after fracture, Young’s modulus, and Poisson’s ratio of the deep shale samples showed an upward trend. The post-peak stress-strain curves exhibited more pronounced fluctuations. Acoustic wave velocities at the plunging end of the Lintanchang anticline were lower than those at the flanks. Young’s modulus and Poisson’s ratio values, corrected using a dynamic-static linear transformation, exhibited improved accuracy. The maximum load borne by the deep shale samples was less than 10 kN. Type Ⅰ and Type Ⅱ fractures displayed notable differences in propagation characteristics, and the degree of fracture penetration was greatly affected by sampling direction. The vertical mechanical profile of well T4 revealed that the bottom section of the first member of the Wufeng-Longmaxi Formation has higher Young’s modulus, lower Poisson’s ratio, and stronger brittleness, while the compressive and tensile strengths, as well as the fracture toughness index, remain relatively low. These mechanical properties show a weak compressive-tensile state, providing favorable conditions for reservoir stimulation. Thus, this interval represents an optimal target for future exploration and development.
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spelling doaj-art-e4217cdbe2574625a4a544729c0e53d32025-08-20T03:07:37ZzhoEditorial Department of Petroleum Reservoir Evaluation and DevelopmentYouqicang pingjia yu kaifa2095-14262025-06-0115340641610.13809/j.cnki.cn32-1825/te.2025.03.007Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experimentsFENG Shaoke, XIONG Liang01. Sinopec Southwest China Oil & Gas Company, Chengdu, Sichuan 610041, China;2. Chengdu University of Technology, Chengdu, Sichuan 610059, ChinaThe southeastern Sichuan region is characterized by complex tectonic structures. The shale gas reservoir from the first member of the upper Ordovician Wufeng Formation to the Lower Silurian Longmaxi Formation is buried at considerable depths, which significantly affects the rock mechanical properties. However, systematic studies remain limited. This study focuses on the deep shale gas reservoir in the Lintanchang area of southeastern Sichuan. A series of mechanical experiments, including triaxial compressive tests, acoustic wave velocity measurements, tensile strength tests, and fracture toughness tests, were carried out. Based on the results of these multi-mechanical experiments, the rock mechanical properties of shale samples were analyzed, and a vertical mechanical property profile for a single well was established. With increasing temperature and pressure, the residual stress after fracture, Young’s modulus, and Poisson’s ratio of the deep shale samples showed an upward trend. The post-peak stress-strain curves exhibited more pronounced fluctuations. Acoustic wave velocities at the plunging end of the Lintanchang anticline were lower than those at the flanks. Young’s modulus and Poisson’s ratio values, corrected using a dynamic-static linear transformation, exhibited improved accuracy. The maximum load borne by the deep shale samples was less than 10 kN. Type Ⅰ and Type Ⅱ fractures displayed notable differences in propagation characteristics, and the degree of fracture penetration was greatly affected by sampling direction. The vertical mechanical profile of well T4 revealed that the bottom section of the first member of the Wufeng-Longmaxi Formation has higher Young’s modulus, lower Poisson’s ratio, and stronger brittleness, while the compressive and tensile strengths, as well as the fracture toughness index, remain relatively low. These mechanical properties show a weak compressive-tensile state, providing favorable conditions for reservoir stimulation. Thus, this interval represents an optimal target for future exploration and development.https://red.magtech.org.cn/fileup/2095-1426/PDF/1748402865920-1998114405.pdf|southeastern sichuan|lintanchang area|deep shale gas reservoirs|multi-mechanical experiments|rock mechanical properties
spellingShingle FENG Shaoke, XIONG Liang
Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
Youqicang pingjia yu kaifa
|southeastern sichuan|lintanchang area|deep shale gas reservoirs|multi-mechanical experiments|rock mechanical properties
title Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
title_full Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
title_fullStr Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
title_full_unstemmed Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
title_short Study on rock mechanical properties of deep shale gas reservoirs based on multi-mechanical experiments
title_sort study on rock mechanical properties of deep shale gas reservoirs based on multi mechanical experiments
topic |southeastern sichuan|lintanchang area|deep shale gas reservoirs|multi-mechanical experiments|rock mechanical properties
url https://red.magtech.org.cn/fileup/2095-1426/PDF/1748402865920-1998114405.pdf
work_keys_str_mv AT fengshaokexiongliang studyonrockmechanicalpropertiesofdeepshalegasreservoirsbasedonmultimechanicalexperiments