试析歧北凹陷异常压力在深层油气藏成藏过程中的控制作用  

The control of abnormal pressure on deep oil/gas pool formation in Qibei sag.

作　　者：张立新[1] 李军[1] 刘淑芝[1] 张琳[1] 

机构地区：[1]大港油田公司地质勘探开发研究院

出　　处：《石油勘探与开发》2000年第5期19-21,共3页Petroleum Exploration and Development

摘　　要：歧北凹陷深层普遍存在异常压力 ,压力系数为 1.2～ 1.6,纵向上分布有 4套幅度不等的高幅泥岩欠压实带 (超压带 )形成压力封隔层 ,即Ed +Es上1、Es中1、Es2 、Es3等 4套泥岩超压层。凹陷沉降初期产生异常高压的主要原因是盆地的快速沉降与巨厚泥岩沉积相配置 ;东营组沉积末期至明化镇组沉积时期 ,沙一中段地层异常压力则主要与烃类生成、黏土矿物转化有关。该凹陷深层油气资源丰富 ,油气藏均具有高压封闭特点。异常压力在深层油气藏的形成过程中起着极其重要的作用 :①异常压力改善了深部砂体的储集性能 ;②上覆超压异常带对下伏油气具有良好的封闭保存作用 ;③异常压力为油气运聚提供了动力。在歧北凹陷寻找超压油藏 ,纵向上应注重沙一下段和沙三段 。There is abnormal pressure all over the deep strata of Qibei sag and the pressure coefficient usually ranges from 1. 2 to 1.6. Vertically, there are four high amplitude mud rock under compactio n belts (also named super pressure belts) with different amplitude and form lon gitudinal pressure packer layers?—Upper Ed+Es 1, Middle Es 1, Es 2 and Es 3 four mud rock super pressure layers. The deep strata in Qibei sag contain ab undant oil and gas resources. The significant characteristics of the deep oil/ga s reservoirs are high pressure sealed. Abnormal pressure plays very important role in deep oil/gas pool forming: (1)abnormal pressure improves properties of the deep reservoir sand; (2)overlying super pressure belt has a sealing and pre serving action to underlying oil and gas; and (3)abnormal pressure offers the dr iving force for the migration and accumulation of oil/gas. Therefore, it was con sidered that when searching for super pressured oil reservoirs, vertically, the stress should be put on the Lower E s 1 and Es 3; horizontally, the stress should be put on the slope area and dee p strata in the depression.

关 键 词：歧北凹陷 异常压力 深层油气藏 成藏 分布特征 

分 类 号：TE122.31[石油与天然气工程—油气勘探] P618.130.2[天文地球—矿床学]