纯41断块沙四段低渗储层裂缝发育特征及期次划分  

Development characteristics and stages of fractures in the low-permeability reservoir of the Fourth Member of Shahejie Formation of Chun-41 fault block

作　　者：时光耀 李理[1] 于少群 徐聪 Shi Guangyao;Li Li;Yu Shaoqun;Xu Cong(School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580;Henan Geological Investigation&Designing Institute CO.,LTD,Zhengzhou 450014)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]河南省建院勘测设计有限公司,郑州450014

出　　处：《地质科学》2021年第3期854-866,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家科技重大专项课题(编号:2017ZX05009001)资助。

摘　　要：通过岩心观察、薄片观测、岩石声发射试验和流体包裹体测定,研究了纯41断块沙四段低渗储层裂缝的特征和发育期次。研究结果表明:纯41断块沙四段低渗储层宏观构造裂缝以直立缝为主,微裂缝以贯通缝为主,裂缝整体开度较小,但充填程度低,裂缝有效性较好,为油气提供有利的运移通道和储集空间。微裂缝尖灭形态可分为树枝形、"人"字形和锯齿形等,形态差异与矿物粒径、磨圆度等有关。古近纪东营凹陷受伸展兼走滑的构造应力场作用控制,主要发育4组构造裂缝,结合声发射试验所显示的凯赛尔点,判断裂缝主要发育期次为沙三—沙二沉积期,次要发育期为东营组沉积末期,裂缝油气充填时期为明化镇组沉积期。Through core observation, slice observation, rock acoustic emission test and fluid inclusion determination, the characteristics and development stages of the low-permeability reservoir in the Fourth Member of the Shahejie Formation of Chun-41 fault block were studied. The results show that vertical fractures are the main type, macro-structural fractures and through fractures are the main micro-fractures in the low-permeability reservoir of the Fourth Member of the Shahejie Formation of Chun-41 fault block. The fracture opening is small, but the filling degree is low. The fracture effectiveness is good, which provides a favorable migration channel and reservoir space for oil and gas. The pinch-out morphology of micro-fractures can be divided into dendritic shape,"ren" shape and zigzag shape, etc. The morphological difference is related to particle size and roundness, etc. Controled by the tectonic stress field of extensional and strike-slip in the Paleogene Dongying Depression, four groups of tectonic fractures mainly developed. Combined with the Kasel point shown by acoustic emission test, it was determined that the main fracture development stage was in period of Es3-2 deposited, the secondary development stage was in period of the Late Ed deposited, and the fracture.s oil filling was in stage of the Minghuazhen Formation deposited.

关 键 词：低渗储层 裂缝期次 发育特征 沙四段 东营凹陷 

分 类 号：TE121.2[石油与天然气工程—油气勘探]