吉木萨尔凹陷二叠系芦草沟组页岩油储层天然裂缝特征与压裂模拟  

Natural fracture characteristics and fracture network simulation in shale reservoirs of Permian Lucaogou Formation in Jimsar Sag

作　　者：徐田录 吴承美[1] 张金凤 曹爱琼 张腾 XU Tianu;WU Chengmei;ZHANG Jinfeng;CAO Aiqiong;ZHANG Teng(Jiqing Oilfield Operation Area,PetroChina Xinjiang Oilfield Company,Jimsar 831700,Xinjiang,China;Xinjiang Zhundong Petroleum Technology Co.,Ltd.,Fukang 831511,Xinjiang,China;Yuanwang Jingsheng Technology(Beijing)Co.,Ltd.,Beijing 100020,China)

机构地区：[1]中国石油新疆油田公司吉庆油田作业区,新疆吉木萨尔831700 [2]新疆准东石油技术有限公司,新疆阜康831511 [3]北京远望景盛科技发展有限公司,北京100020

出　　处：《岩性油气藏》2024年第4期35-43,共9页Lithologic Reservoirs

基　　金：国家科技重大专项“岩性地层油气藏成藏规律、关键技术及目标评价”(编号:2016ZX05001-002);中国石油集团重大科技专项“陆相中高成熟度页岩油勘探开发关键技术研究与应用”(编号:2019E-2609)联合资助。

摘　　要：综合利用岩心、地震、测井和微地震监测等资料,在天然裂缝模型和地应力模型的约束下,运用页岩储层压裂缝网模拟研究了吉木萨尔凹陷二叠系芦草沟组天然裂缝特征及其对压裂缝网扩展的影响。研究结果表明:(1)吉木萨尔凹陷二叠系芦草沟组天然裂缝包括层理缝和构造缝,以层理缝为主,数量多、倾角小,裂缝数量平均为251条,裂缝面密度为0.58~1.34条/m,平均为0.93条/m。构造缝倾角为70°~95°,裂缝数量明显少于层理缝,根据形成时间及产状,构造缝可分为Ⅰ类和Ⅱ类构造缝。(2)研究区最小水平主应力为50.41~55.22 MPa,最大水平主应力为53.52~74.43 MPa,有利于水力压裂缝网的延伸,芦草沟组纵向存在应力隔层,最大层间应力差可达12 MPa,水力压裂时人工裂缝不易穿层。(3)研究区芦草沟组页岩压裂改造以激活高角度构造缝为主,96.45%的压裂缝为“T形”裂缝,而“十字形”和“一字形”压裂缝仅占2.24%和1.21%,芦草沟组压裂缝半缝长度为70~100 m,高度为10~30 m,邻近断层时由于缝长过大,易发生井窜。Based on core,seismic,logging,and microseismic monitoring data,and under the constraints of natural fracture models and geostress models,the characteristics of natural fractures and their impact on the ex‐pansion of fracture networks in Permian Lucaogou Formation in Jimsar Sag were studied through fracture net‐work simulation in shale reservoirs.The results show that:(1)The natural fractures of Permian Lucaogou For‐mation in Jimsar Sag include bedding fractures and structural fractures,with the bedding fractures as the main type,having a large number and small dip angles.The average number of fractures is 251,and the fracture sur‐face density is 0.58-1.34 per meter,with an average of 0.93 per meter.The dip angle of the structural fractures is 70°-95°,and the number of fractures is significantly less than that of the bedding fractures.According to the for‐mation time and occurrence,the structural fractures can be divided into typeⅠand typeⅡstructural fractures.(2)The minimum horizontal principal stress in the study area is 50.41-55.22 MPa,and the maximum horizontal principal stress is 53.52-74.43 MPa,which is conducive to the extension of hydraulic fracturing network.There are stress barriers in the vertical direction of Lucaogou Formation,and the maximum interlayer stress difference can reach 12 MPa,so it is not easy for the artificial fracture to penetrate the layers during hydraulic fracturing.(3)The fracturing transformation of shale of Lucaogou Formation in the study area is mainly to activate the high-angle structural fractures.96.45%of the fracturing fractures are“T-shaped”,while the“cross-shaped”and“straight-shaped”fractures only account for 2.24%and 1.21%,respectively.The half-length of the fractures of Lucaogou Formation is 70-100 meters,and the height is 10-30 meters.When adjacent to faults,due to the exces‐sive fracture length,well-channeling is prone to occur.

关 键 词：页岩油储层 水力压裂 天然裂缝 层理缝 构造缝 压裂扩展模拟 芦草沟组 二叠系 吉木萨尔凹陷 

分 类 号：TE319[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]