塔里木盆地塔中隆起区石炭系东河砂岩油气藏的假盖层

FALSE CAP ROCK OVER THE OIL AND CAS ACCUMULATION OF THE CARBONIFEROUS DONGHE SANDSTONE IN THE UPWELLINC AREAS OF THE MID-TARIM BASIN

张尚锋 罗传容 肖传桃

Zhang Shangfeng Luo Chuanrong Xiao Chuantao

江汉石油学院测试中心, 湖北荆沙市 434102

Jianghan Petroleum College, Jingsha City, Hubei 434102

塔里木盆地塔中隆起区石炭系东河砂岩油气藏是一个具有地层控制因素的构造圈闭油气藏.经钻井、测试资料揭示,在塔中10、16、20井区东河砂岩油气藏的油气似乎未充满至构造溢出点.东河砂岩之上的含砾砂岩段的沉积相变化较大,物性好坏亦有变化.压汞资料显示,在该段物性变差的地区,对东河砂岩油气藏起隔膜型封堵作用,属泥岩段(盖层)与砂岩段(储层)之间的过渡层,称“假盖层”.

The oil and gas accumulation of the Carboniferous Donghe sandstone in the upwelling areas of the Mid-Tarim Basin is a structural trap accompanying with stratigraphic control factors.The analysis on well and test data appears that petroleum in the accumulation of Donghe sandstone seemingly has not filled to structural spillpoint in wells 10,16 and 20 in field of the Mid-Tarim Basin.The sedimentary factes in gravel-bearing sandstone member over Donghe sandstone vary dramatically and their porosity changes between good and bad.Mercury-injection data show that in the porosity-worsening areas of the member,oil and gas accumulation plays an insulating membrane-typed plugging part to Donghe sandstone,belongs to transitional bed betweeen mudstone member(cap rock)and sandstone member(reservoir)and is called "false cap rock".

https://doi.org/10.11781/sysydz199604371