The present-day in-situ stress filed characteristic of deep shale reservoirs and its effect on the reconstruction of shale reservoirs: A case study of the Yongchuan shale gas field in South Sichuan Basin

被引：0
作者：
Li Y. [1 ]
He J. [1 ,2 ]
Deng H. [1 ,2 ]
Wei L. [3 ]
Wang Y. [4 ]
Li R. [1 ,2 ]
Cao F. [1 ]
Yin S. [5 ]
机构：
[1] College of Energy, Chengdu University of Technology, Sichuan, Chengdu
[2] State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Sichuan, Chengdu
[3] Exploration and Development Research Institute Sinopec Southwest Oil and - Gas Company, Sichuan, Chengdu
[4] Hainan Branch of China National Offshore Oil Corporation Ltd., Hainan, Haikou
[5] School of Earth Sciences and Engineering, Xi'an Shiyou University, Shaanxi, Xi'an
来源：
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | 2024年 / 53卷 / 03期
关键词：
deep shale; fracture mechanical effectiveness; hydraulic fracturing; in-situ stress characteristic; reservoir engineering quality; South Sichuan Basin; Wufeng-Longmaxi Formation;
D O I：
10.13247/j.cnki.jcumt.20230307
中图分类号：
学科分类号：
摘要：
The present-day in-situ stress characteristic of deep shale reservoirs and the impact of fracture efficacy and fracturing effect under their control is still unclear. Taking the Yongchuan shale gas play in southeastern Sichuan baisn as an example, the hydraulic fracturing method, rock acoustic emission experiment, logging data, and numerical simulation were used to clarify the stress characteristic of deep shale reservoirs and its effect on the reconstruction of shale reservoirs. Our findings demonstrate that the deep shale reservoirs in the southeast Sichuan basin are currently experiencing strike-slip and strike-slip with the tension, and some areas are experiencing strike-slip with the compression. Its difference of in-situ horizontal stresses mostly range from 10 to 30 MPa[0. 05-0.3 Sy(Sy: Vertical principal stress)], a prevailing near EW (92° -105°) trending SHmax orientation, and obviously affected by faults and folds. The buried depth has little impact on the lateral stress coefficient (K) , which typically ranges from 0. 9 to 1. 1 and is close to 1. 0. Deep shale reservoirs have a low fracture friction coefficient (typically less than 0. 2) , and natural fractures with a medium-high dip angle O45° + 10°) and an angle between 15° and 65° with the maximum horizontal stress have favorable mechanical effectiveness following transformation. The present-day in-situ stress has a certain control effect on the permeability. As the difference of in-situ horizontal stresses increases, the complexity of the fracture network gradually decreases, and the fracturing impact deteriorates. The shear stress produced by the off-azimuth well induce the hydraulic fracture to produce a larger kinking angle 040°). Deep shale forms a stress barrier in the longitudinal direction due to litho-facies differences. The region of strike-slip with tension has a better overall reconstruction impact. Our results can provide a reference for the study of in-situ stress in deep shale reservoirs and the efficient exploration and development of deep shale gas. © 2024 China University of Mining and Technology. All rights reserved.
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页码：546 / 563
页数：17
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