辽河西部凹陷船舱式油气运聚系统特征初探

辽河坳陷西部凹陷发育2套区域性异常流体超压封盖层，将凹陷分隔成上、中、下3层各自独立的层状流体封存系统。因超压封盖层深度较固定，不随层位变化，将其称为“船舱式流体封存系统”。下舱的顶板深2900～3300m，是形成最早、演化程度最高的油气发生器，生成的油气最丰富，大部分已向上运移到中舱和上舱；中舱深度为1200～2900m，具有广泛分布的高孔渗优质储集层和良好的超压封盖层，并发育良好的圈闭，最有利于油气成藏；上舱为1200m以浅，是开放式油气赋存系统，其边缘开启带处于湖盆岸线附近，是上、中、下3层舱泄漏油气的共同排放带，油气来源丰富，成为稠油富集带。西部凹陷应加强中舱的勘探，在继续加强构造油气藏勘探的同时，应以寻找岩性等隐蔽油气藏为主；在上舱，应注重寻找浅层气和稠油；下舱勘探以寻找各凹陷的低潜山油藏为主。

Cabin-type oil and gas migration characteristics of the Western Sag, Liaohe Depression

Based on a systematic study of the fluid pressure system of the Western Sag in the Liaohe Depression, Eastern China, the concept of Cabin type oil and gas migration system is herin proposed and modeled. Within the cabin, three systems are identified: a basal system ranging from 2900 to 3300 m in depth, a middle system from 1200 to 2900m, and an upper system above 1200 m. The middle cabin is the best oil trap because of its excellent super high pressure seal and high porosity reservoir. For the Western Sag, attention should be paid to the upper cabin for exploiting shallow gas and heavy oil pools. In the lower cabin, lower buried hills in some sags should be the exploration targets.