渤海湾盆地济阳坳陷沾化凹陷地层流体压力分布规律及其对油气成藏的影响

结合实测资料及理论计算，划分出了6种不同的异常压力类型。沾化凹陷油气藏以正常压力为主，但深部地层存在异常高压油气藏。平面上，沾化凹陷异常高压主要发育在陡坡与凹陷中心，而低压在缓坡相对发育。纵向上，深部欠压实带发育异常高压，中部混合压实带高压与低压均可出现，而上部正常压实带以常压为主。沾化凹陷深部油气勘探的重点应为高势区中的相对低势区或高势区相邻的低势区．重点问题是结合压力与势分布寻找有利储层和隐蔽圈闭．

DISTRIBUTING CHARACTERISTICS OF FLUID PRESSURE IN THE ZHANHUA SUBBASIN, JIYANG DEPRESSION,BOHAI GULF BASIN, AND THEIR INFLUENCE ON OIL AND GAS ACCUMULATIONS

Six types of fluid pressure are distinguished on the basis of integrating measured data and theoretical calculation. Normal pressure is dominant in oil and gas accumulations in the Zhanhua subbasin, but high abnormal-pressure oil and gas accumulations exist in strata at depth. In a plan view, high abnormal pressure mainly occurs in areas of steep slopes or subbasin centers; whereas low abnormal pressure occurs on gentle slopes. In vertical sections, high abnormal pressure mainly occurs in the less compacted zone at depth; both high and low abnormal pressures may appear in the mixed compaction zone at moderate depth; and normal pressure predominates in the normal compaction zone at shallow depth. The target of petroleum exploration in the deep part of the Zhanhua subbasin should be relatively low potential areas in high potential areas or low potential areas near high potential areas, and one of the important problems lies in combining the distribution characteristics of fluid pressure with the potential distribution to look for hidden traps and favorable reservoirs.