摘要
根据露头、岩心和成像测井等资料研究认为,鄂尔多斯盆地宁县—合水地区延长组长7致密储集层发育构造裂缝和成岩裂缝,高角度构造裂缝为主要裂缝类型。高角度剪切裂缝有东西向、南北向、北西—南东向和北东—南西向4组,其中以北东—南西向和东西向为主。裂缝发育程度受控于岩性、层厚、沉积微相和岩层非均质性等因素,其中,非均质性是主要因素。长7致密储集层天然裂缝发育,受现今地应力影响,北东—南西向裂缝会优先启动,成为主要的渗流通道,同时岩石脆性指数高,有利于体积压裂,形成复杂的裂缝网络系统。
Based on the data of outcrops,cores and imaging logs,structural fractures and diagenetic fractures develop in the tight sandstone reservoirs of Chang-7 member of Yanchang formation in Ningxian-Heshui area in Ordos basin,of which the high-angle shear fractures are dominant,with four sets of orientations like EW,SN,NW-SE and NE-SW,dominated by NE-SW and EW fractures.The big variation of fractures is affected by the lithology,bedding thickness,sedimentary micro-facies and rock heterogeneity,among which the rock heterogeneity is the main factor affecting such a reservoir＇s fracture development degree.Also,the development of natural fractures of Chang-7 member is subjected to the effect of current stress field.The preferential open NE-SW fracture system will be the main seepage channels.The high rock brittleness index is favorable for volumetric fracturing,forming complex fracture network system in it.
出处
《新疆石油地质》
CAS
CSCD
北大核心
2013年第4期394-397,共4页
Xinjiang Petroleum Geology
基金
国家科技重大专项(2011ZX05013-004)
关键词
鄂尔多斯盆地
延长组
天然裂缝
致密储集层
发育特征
体积压裂
Ordos basin
Yanchang formation
natural fracture
tight reservoir
development feature
volumetric fracturing
