摘要
川南泸州区块是中国重要的页岩气产区,其内五峰-龙马溪组页岩气资源丰富,勘探-开发潜力巨大。现今地应力在页岩气运移与富集规律分析、钻完井工程、储层压裂改造以及井网部署等方面均具有重要应用。分析泸州区块五峰-龙马溪组深层页岩气储层现今地应力状态,并探讨在其影响下的天然裂缝活动性与压裂裂缝扩展。结果表明:五峰-龙马溪组页岩气储层现今地应力方向呈现WNW-ESE的优势方位;现今地应力值大小为:水平最大主应力最大、垂向主应力居中、水平最小主应力最小,指示走滑型地应力机制。五峰组和龙一11小层水平主应力差分别介于11.90~15.76 MPa和11.80~16.75 MPa范围内,具备形成复杂压裂缝网的地应力条件。在现今地应力条件下,川南泸州区块五峰-龙马溪组页岩气储层天然裂缝不活动,随着开发流体的注入,天然裂缝逐渐活化,其压力增量的临界值为15~23 MPa;压裂后主要形成垂向延伸的裂缝系统。研究成果可为川南泸州区块深层页岩气效益开发提供现今地应力分析的基础与科学依据。
The Luzhou Block in southern Sichuan Basin is an important shale gas production area in China,where the Wufeng-Longmaxi Formation shale gas resources are abundant,indicating a high exploration and development potential.The present-day in-situ stress has important applications in the analysis of shale gas migration and enrichment,drilling and completion engineering,reservoir fracturing and well pattern deployment,etc.The present-day in-situ stress state of Wufeng-Longmaxi Formation deep shale gas reservoirs in the Luzhou block was analyzed,and natural fracture activity and hydraulic fracture propagation under the effect of present-day in-situ stresses were discussed.The research results show that the dominant present-day in-situ stress orientation in the Wufeng-Longmaxi Formation shale gas reservoir is WNW-ESE-trending.The magnitude of horizontal maximum principal stress is the largest,magnitude of horizontal minimum principal stress is the lowest,indicating a strike-slip stress regime.The stress difference in the Wufeng Formation and S 1 l 1-1-1 layer is 11.90~15.76 MPa and 11.80~16.75 MPa,respectively,which is beneficial for generating complex fracture networks.Under the present-day in-situ stress conditions,natural fracture activity in the Wufeng-Longmaxi Formation shale gas reservoirs of Luzhou Block is relatively weak.With fluid injection during shale gas development,natural fractures are gradually activated,and their critical pressure increase is 15~23 MPa.Hydraulic fractures vertically propagate under the strike-slip stress regime.The results can provide present-day in-situ stress analysis basis for further beneficial development of deep shale gas in the Luzhou Block of southern Sichuan Basin.
作者
刘钰洋
鞠玮
熊伟
郭为
宁卫科
于国栋
梁孝柏
李永康
LIU Yu-yang;JU Wei;XIONG Wei;GUO Wei;NING Wei-ke;YU Guo-dong;LIANG Xiao-bai;LI Yong-kang(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process,Ministry of Education,Xuzhou 221008,China;School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China)
出处
《科学技术与工程》
北大核心
2024年第8期3200-3206,共7页
Science Technology and Engineering
基金
中国石油天然气股份有限公司科技管理部前瞻性基础性技术攻关项目(2022DJ80)
中国石油油气和新能源分公司重点科技项目(2022KT1204)。
关键词
现今地应力
地应力剖面
裂缝活动性
深层页岩气
泸州区块
the present-day in-situ stress
in-situ stress section
fracture activity
deep shale gas
Luzhou block
