临南洼陷沙河街组三段异常低压分布特征及成因机制  

Characteristics and genetic mechanism of abnormal low pressure of the third member of Shahejie formation,Linnan subsag

作　　者：王翘楚 陈冬霞[1] 宋国奇[2] 王永诗[2] 张碧璇 王福伟 王梓颐 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石化胜利油田分公司,山东东营257000

出　　处：《东北石油大学学报》2018年第1期49-59,共11页Journal of Northeast Petroleum University

摘　　要：临南洼陷沙河街组三段地层低压明显,与邻近凹陷特征明显不同。根据临南洼陷沙三段37口探井、99个地层压力实测数据,结合定性判断和定量计算,分析低压分布特征及成因机制。结果表明:临南洼陷低压区域主要分布于中央隆起带之上的临盘及商河地区,在洼陷西部和西南部边缘也有发育,压力因数为0.82~0.95。异常低压主要与地层剥蚀卸载、地层降温及断层控制作用有关。地层剥蚀卸载引起压力下降幅度为1.00~8.43 MPa,是形成异常低压的主要因素;地层降温引起压力下降幅度为0.50~3.00 MPa。研究区临商断裂带、夏口断裂带主体断层及洼陷西南部边缘断层的封闭性较好,低压区域被保存;临商断裂带西侧部分断层封闭性较差,局部低压区域被破坏。该研究结果为临南洼陷下一步油气勘探提供指导。Linnan subsag is characterized by subnormal pressure in the third member of Shahejie formation(Es3),which is different from that in other adjacent sags.Based on 99 measured pressure data from37 wells,we analyze the characteristics of distribution and genetic mechanism of abnormal low pressure.This study combined quality and quantity analysis with an angle of petroleum geology.The result showed that abnormal low pressure was more developed in central uplift belt than central zone and northern slope belt with the pressure coefficient from 0.82 to 0.95.In depth,the range of abnormal low pressure was mainly from 2 500.0 mto 3 500.0 m,and low pressure in shallow layer was rare.Uplifterosion of strata had the largest influence of pressure which caused a decrease of pressure from 1.00 to8.43 MPa;while decrease of temperature was another important factor which led the decrease of pressure for about 0.50 to 3.00 MPa.In the study area,the main faults of Linshang fault zone,Xiakou fault zone and faults located in the edge of southwest of the subsag all have well sealing,where the subnormal pressure was obvious.And because of the poor sealing of part of faults which located in the west side of Linshang fault zone,some of the subnormal pressure was broken.That demonstrated the characteristic of faults is of great significance for distribution of subnormal pressure.

关 键 词：异常低压 形成机制 地层压力 地层剥蚀卸载 沙河街组三段 临南洼陷 

分 类 号：P618.130.1[天文地球—矿床学]