伏龙泉——顾家店背斜带油气成藏规律

RESERVOIR FORMATION LAW OF FULONGQUAN GUJIADIAN ANTICLINAL BELT

本文从油气的来源、断裂系统的发育特征、储集相带的展布和砂体发育特征三个方面 ,对伏龙泉—顾家店背斜带的成藏主控因素进行了系统分析 ,总结油气成藏规律 ,指出伏龙泉构造北高点具有一定的油气前景。断陷层和坳陷层分属上、下两套不同的断裂系统 ,不发育“通天”的逆断层 ,其中 ,断陷层主要发育 3条后退式的同生断层 ,控制了断陷层地层的发育 ;坳陷层发育数目众多的小断层 ,对原生油气藏起到破坏和重新调整的作用 ;断坳转化阶段的登娄库组顶面发育的断层较少。由于上、下断层不连通 ,中深层 (营城组、登娄库组 )的油气保存条件较好。根据已有钻井的气显示反馈 ,认为坳陷层区内的浅层气藏是次生的残留气藏 ,各井的气显示差异、气藏的含气面积和充满程度主要受断层和岩相两种因素控制。根据研究成果 。

According to hydrocarbon source, fault system features, reservoir facies and sand body growth property, the major factors of controlling reservoir formation in Fulongquan-Gujiadian anticlinal belt are analyzed; the reservoir formation law is summarized and it is pointed that the hydrocarbon potential of the northern high of Fulongquan structure is relatively fair. Rift formaton and depression formation belong to upper and lower two sets of fault systems respectively and there is no any big reverse faulf extending to surface. The rift formation mainly shows three retreating-style contemporaneous faults, which controlled the development of rift strata; the depression formation shows a lot of small faults, which plays destruction and rejustment roles in primary oil and gas reservoirs. There are a few faults in the top of Denlouku Formation in rift-depression transformation stage. The preservation conditions of oil and gas in mid-depth strata (Yuancheng Formation and Denlouku Formation) are good, because the upper faults aren't interconnected with the lower ones. In light of the data on gas showings in drilling, it is considered that the shallow gas reservoirs in the depression formation area are the secondary remnant ones, and the difference of gas showing in various wells and the gas-bearing area and gas column height of the gas reservoir are mainly controlled by faults and facies. A suggestion on attaching importance to the oil and gas exploration in mid-depth strata in the northern high of Fulongquan structure is proposed according to the results of research.