低渗透砂岩油藏注水诱导裂缝发育的主控因素——以鄂尔多斯盆地安塞油田W区长6油藏为例  

Major factors controlling waterflooding-induced fracture development in low-permeability reservoirs—A case study of Chang 6 reservoir in W block in Ansai oilfield,Ordos Basin

作　　者：赵向原[1] 吕文雅[2] 王策[3] 朱圣举[3] 樊建明[3] Zhao Xiangyuan;Lyu Wenya;Wang Ce;Zhu Shengju;Fan Jianming(Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Changqing Oilfield Branch Company Ltd.,PetroChina,Xi'an,Shaanxi 710018,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油长庆油田分公司,陕西西安710018

出　　处：《石油与天然气地质》2020年第3期586-595,共10页Oil & Gas Geology

基　　金：国家科技重大专项(2017ZX05013-004,2017ZX05009-001)。

摘　　要：低渗透油藏在长期注水开发过程中会产生注水诱导裂缝,严重影响油藏开发特征。以鄂尔多斯盆地安塞油田W区长6油藏为例,利用地质、测井、分析测试及生产动态等资料,对注水诱导裂缝形成及发育的主控因素进行了研究。注水诱导裂缝在形成和发育过程中主要受地质和工程两大因素综合控制,其中地质因素包括天然裂缝、现今地应力、储层构型及储层岩石力学性质等,工程因素主要包括人工裂缝和注采参数(如注水时长、注水量、注采比或注采量)等。天然裂缝和人工裂缝为注水诱导裂缝的形成提供了物质条件;现今地应力控制了注水诱导裂缝发育的优势方向,并间接影响其延伸过程中的难易程度;不同级次构型单元控制注水诱导裂缝的规模,不同级次的构型界面影响注水诱导裂缝的持续延伸;储层岩石力学参数一定程度上影响了注水诱导裂缝的延伸路径;注采参数则直接控制了注水诱导裂缝的形成和延伸速度。Waterflooding-induced fractures are the by-products during long-term water-injection in low-permeability reservoirs,seriously affecting the performance of oil reservoir.We study the major factors controlling the formation and development of these factures in Chang 6 reservoir in Ansai oilfield,Ordos Basin,using geological,logging,testing and production performance data.The formation of these fractures is mainly controlled by both geological and engineering factors.The geological factors refer to natural fractures,current in-situ stress,reservoir architecture and rock mechanical properties,and the engineering factors mainly include artificial fractures and injection-production parameters(such as injection time and volume,injection-production ratio or injection-production volume,etc.).Natural and artificial fractures serve as physical stimuli to the formation of waterflooding-induced fractures;current in-situ stress controls the dominant direction of the fractures,and indirectly affects their propagation;architecture units and architecture interfaces of various levels control the scale and propagation extent respectively;reservoir rock mechanical parameters constrain,to a certain extent,the propagation routes;and injection-production parameters control the formation and propagation speed to the most.

关 键 词：注水诱导裂缝 注水开发 低渗透油藏 安塞油田 鄂尔多斯盆地 

分 类 号：TE348[石油与天然气工程—油气田开发工程]