中国地质2024，Vol.51Issue(1)：89-104,16.DOI:10.12029/gc20230306005
川西孝泉—丰谷地区须二段深层致密砂岩储层地应力大小评价方法及其工程应用
Evaluation method and engineering application of in-situ stress of deep tight sandstone reservoir in the second member of Xujiahe Formation in Xiaoquan-Fenggu area,western Sichuan
摘要
Abstract
This paper is the result of oil and gas exploration survey engineering. [Objective]Xiaoquan-Fenggu area in the western Sichuan Basin has huge potential for exploration and development of Xujiahe Formation gas reservoirs.However,due to the region's deep burial,complex structure,and multiple superimposed fault systems that cause frequent variation in stress orientation,effective well placement design and hydraulic fracturing practices have been limited.Therefore,it is necessary to evaluate the precise magnitude of in-situ stress in this area to provide recommendations for engineering development and increase production capacity.[Methods]Experimental methods such as rock mechanics,acoustic emission testing,and differential strain analysis combined with conventional logging,special logging,and hydraulic fracturing data were used to experimentally test the in-situ stress magnitude in deep heterogeneous blocky tight sandstone reservoirs.Based on accurate evaluation of single-point in-situ stress magnitude,a logging interpretation model was established for the subdivision of tectonic units in the study area,examining structural variation of in-situ stress magnitude and distribution along a single well.[Results]Our study showed that differential strain analysis provided the most accurate measurement of stress in heterogeneous tight sandstone reservoirs.Test results indicated that the Xujiahe Formation belongs to the type Ⅲ in-situ stress category and exists in a strike-slip stress state with partial compression and thrust stress states.Based on single-point test data,we developed a technique to evaluate in-situ stress magnitude by utilizing borehole image inversion.Structural changes in in-situ stress magnitude were divided vertically into five types,whereby high positions of north-south(SN)faults with grades above three and folds in SN or northeast-trending(NEE)resulted predominantly in low-low-high(LLH)or low stress(LC)profiles.Meanwhile,small-scale faults or gentle deformation areas had high-low-high(HLH)or high-low-low(HLL)profiles.[Conclusion]A low-low-high(LLH)stress profile was suggested for engineering development to penetrate more gas layers vertically,while avoiding bottom water and preventing rapid water breakthrough during early production.Therefore,it is recommended to select the second to third order north-south(SN)trending faults and north-south(SN)or northeast trending(NE)longitudinal flexure zones located in the middle-upper part of the second layer of the second member of Xujiahe Formation.关键词
地应力大小/应力结构/致密气藏/声发射/诱导缝/须二段/油气勘查工程/川西凹陷/四川Key words
in situ stress/stress structure/tight gas reservoir/acoustic emission/induction seam/the second member of Xujiahe Formation/oil and gas exploration engineering/western Sichuan Depression/Sichuan Province分类
天文与地球科学引用本文复制引用
黄滔,刘岩,何建华,叶泰然,邓虎成,李瑞雪,李可赛,张家维..川西孝泉—丰谷地区须二段深层致密砂岩储层地应力大小评价方法及其工程应用[J].中国地质,2024,51(1):89-104,16.基金项目
深地科学与工程教育部重点实验室开放基金项目(DESEYU202102)与四川省科技厅重点苗子项目(22MZGC0159)联合资助.Supported by the Open Found from Key Lab of Deep Earth Science and Engineering,Ministry of Education(No.DESEYU202002),Sichuan Provincial Science and Technology Department Key Seedling Project(No.22MZGC0159). （DESEYU202102）
