鄂西宜昌地区寒武系水井沱组页岩储层地应力特征及成因  

Characteristics and causes of in-situ stress in shale reservoir of the Cambrian Shuijingtuo Formation in Yichang Area,Western Hubei Province

作　　者：童广勤 苗凤彬 李培军[1,3,4,5] 秦维秉 罗胜元[1,3,4,5] 陈林 TONG Guangqin;MIAO Fengbin;LI Peijun;QIN Weibing;LUO Shengyuan;CHEN Lin(Hubei Key Laboratory of Operation Safety of High Dam and Large Reservoir,Yichang,Hubei 443133,China;River Basin Hub Operation Management Center,China Three Gorges Corporation,Yichang,Hubei 443133,China;Wuhan Center of China Geological Survey,Wuhan,Hubei 430205,China;Technology Innovation Center for Shale Oil and Gas Accumulation Theory and Engineering in Southern Complex Structural Area,China Geological Survey,Wuhan,Hubei 430205,China;Shale Gas Research Center for Southern Complex Structural Area,Wuhan,Hubei 430205,China)

机构地区：[1]高坝大库运行安全湖北省重点实验室,湖北宜昌443133 [2]中国长江三峡集团有限公司流域枢纽运行管理中心,湖北宜昌443133 [3]中国地质调查局武汉地质调查中心,湖北武汉430205 [4]中国地质调查局南方复杂构造区页岩油气成藏理论与工程技术创新中心,湖北武汉430205 [5]南方复杂构造区页岩气研究中心,湖北武汉430205

出　　处：《东北石油大学学报》2024年第2期86-101,I0006,I0007,共18页Journal of Northeast Petroleum University

基　　金：中国长江三峡集团有限公司科技计划项目(0799276);国家自然科学基金项目(42302134);湖北省自然科学基金项目(2021CFB293);中国地质调查局地质调查项目(DD20230323);古生物与地质环境演化湖北省重点实验室基金项目(PEL-202307)。

摘　　要：以四川盆地宜昌地区水井沱组页岩储层为对象,采用钻井实测、岩心测试分析及测井解释等技术,获取多井点现今地应力信息,研究地应力特征,探讨应力差异分布成因。结果表明:宜昌地区水井沱组现今最大水平主应力方向总体为NEE向,东、西部靠近边界断裂的区域呈多向性;现今地应力的离散性较强,平面上呈中部高、东西部低的主体分布特征,纵向上随深度增加而增大;埋藏深度是导致地应力纵向上分布差异的主要因素,三个主应力随埋深呈线性增加,主体区域的应力关系表现为水平最大主应力>垂向主应力>水平最小主应力,属于走滑断层应力状态;不同岩性层间的水平应力及方向变化,由灰岩、粉砂岩到页岩,应力总体上呈减小趋势;边界断裂的影响是地应力平面上分布差异的主要成因,造成地应力降低及最大水平主应力趋于平行断层走向的偏转,地应力降低与偏转幅度主要受断裂距离控制。该结果可为宜昌地区水井沱组页岩气藏后续勘探部署及压裂施工方案设计提供依据。Yichang Area is a new area for shale gas exploration outside the Sichuan Basin.Taking the shale reservoir of Shuijingtuo Formation in the area as the object,drilling measurements,core testing analysis and logging interpretation were used to obtain current stress information from multiple well points.The study of in-situ stress characteristics was carried out,and the causes of stress difference distribution were discussed.The results show that the current maximum horizontal principal stress direction of the Shuijingtuo Formation in Yichang Area is generally in the NEE direction,and the areas near the boundary fault in the east and west show multi-direction.The current in-situ stress has strong discreteness,showing a main distribution characteristic of high in the middle and low in the east and west in the plane,and increasing with depth in the vertical direction.The burial depth is the main factor leading to differences in the vertical distribution of in-situ stress.The principal stress value increases linearly with burial depth.The principal stress from large to small in the main burial depth area of shale reservoirs is the maximum horizontal stress,vertical stress and minimum horizontal stress,which belongs to the stress state of strike-slip fault.The horizontal stress value and direction of different lithological layers are change.From limestone,siltstone to shale,the stress value generally shows a decreasing trend.The influence of boundary faults is the main cause of the distribution differences of in-situ stress on the plane.Boundary faults cause a decrease of in-situ stress values and a deflection of maximum horizontal principal stress direction parallel to the fault strike.The decrease in stress values and the amplitude of deflection are mainly controlled by the distance from the fault.The research results can provide a basis for the subsequent exploration deployment and fracturing construction plan design of the Shuijingtuo Formation shale gas reservoir in Yichang Area.

关 键 词：地应力特征 成因 页岩储层 水井沱组 鄂西宜昌地区 

分 类 号：TE122[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]