港西油田浅层气成藏条件

为寻找中国石油大港油田公司的接替资源，分析了港西油田浅层气藏储层条件、气源条件、运移条件以及浅层气得以保存的有利条件，结果表明：①储集层主要由馆陶组辫状河沉积砂体和明化镇组曲流河沉积砂体组成，砂体横向分布不稳定、浅层速度变化快，为研究区主要含气层系，储层物性好，为新近系油气提供了良好的储集空间；②港西地区断层发育，新近系和古近系又是不整合接触，为港西油田凸起的浅层气从深层往上运移创造了良好的条件，浅层区孔渗性好，烃源岩丰度高，因此砂层也成为有效的输导系统；③馆陶组、明化镇组均发育较好盖层，成藏和保存条件优越。结论认为：港西油田浅层天然气具有良好的油气勘探前景。

Gas pooling conditions of shallow reservoirs in the Gangxi oil field

The shallow gas pools in the Gangxi oil field are characterized by shallow burial depth, complex origin, small reservoir volume, multiple types, and extensive distribution. An analysis is performed on the reservoir, gas source, migration and preservation conditions of the shallow gas pools in the study area. The following results are obtained. ①The braided river sandbodies in the Guantao Formation and meander river sandbodies in the Minghuazhen Formation are the main reservoirs with unstable lateral distribution, a rapid change of shallow layer velocity, and good poroperm characteristics, and they provide good space for the accumulation of the Noegene oil and gas. ②The well-developed faults and the unconformity between the Noegene and Paleogene provide favorable pathways for the deep gas to migrate upward into the shallow reservoirs. In addition, the sandstones with good poroperm characteristics can also act as effective carrier systems for the migration of gas generated by the shallow source rocks with high organic abundance. ③Both the Guantao and the Minghuazhen formations have well-developed seals, favorable for the preservation of gas. Therefore, gas potential is relatively large in the shallow reservoirs of the Gangxi oil field.