特低渗透油藏动态裂缝非均质性和复合砂体内部构型对开发的意义

Heterogeneity on dynamic fracture,internal configuration of compound sand body and significance to the development of ultra-low permeability reservoir reservoir in Erdos Basin

综合利用岩心、地质露头、密井网的测井和生产动态资料,研究特低渗透油藏动态裂缝非均质性,并对复合砂体内部构型进行精细解剖,分析其对油田开发的意义,为特低渗透油田稳产和提高采收率提供地质基础。研究认为,动态裂缝是特低渗透油藏中、高含水阶段最强的非均质特征,它是注水过程中产生的新生、有效的裂缝,并不断增长,其受现今地应力控制,与开发技术政策相关;动态裂缝可从静、动态两方面进行综合识别,其严重影响了水驱波及体积。结合地质露头和密井网资料建立了三角洲前缘复合砂体垂叠、侧叠、堆叠和拼接4种叠置关系,且细分为10种接触关系,并对连通性进行了分析;在裂缝与井网关系匹配的基础上,可有效指导平面均衡注水、精细分层注水以及开发技术政策的制订。

Comprehensively utilizing core,geological outcrop,well logging of dense well pattern and production data,we studied heterogeneity of dynamic fracture and finely dissected the internal configuration of compound sand body in ultra-low permeability reservoir,then analyzed the significance to oilfield development for providing geological basis for stable yield and improving the recovery.The research shows,dynamic fractures are the strongest heterogeneity characteristic in the middle-high water cut stage of ultra-low permeability reservoir,which are the new,effective cracks generated in the process of water injection and continuously grow controlling by nowadays′stress field.They are associated with water injection technology policy.Dynamic fractures can be recognized from two aspects of static and dynamic data,which seriously influence water flooding swept volume.Combined with geologic outcrop and dense well pattern data,to compound sand body of delta front,we established 4 superimposed relationships including vertical piling,side piling,stacked piling and joining,subdivided into 10 kinds of contact relations and analyzed the connectivity.On the basis of matching between fracture and well pattern orientation,these would effectively guide balancing water injection in the plane,fine layering injection and drawing up of development technology policy.