渤海湾盆地东营凹陷牛庄洼陷岩性油气藏平面富集主控因素

随着油气勘探程度的加深，岩性油气藏的重要性日益显现，而查明油气富集规律是岩性油气藏勘探的关键。渤海湾盆地东营凹陷牛庄洼陷沙三中亚段发育大量岩性油气藏，文章以此为研究目标，着重分析其平面上油气分布的主要控制因素。研究结果表明，牛庄洼陷岩性油气藏的分布受控于洼陷内流体性质、断层作用和沉积相展布3种地质因素。它们对洼陷区岩性油气藏富集规律的影响分别在于：洼陷内流体运聚单元控制着油气在平面上的富集区，牛庄洼陷南北两侧汇聚流发育区是油气聚集的有利地带，而洼陷北部平行流和东西两侧发散流发育区不利于油气成藏；同生断层泵吸作用使得油气在牛庄洼陷平行流和发散流发育区可形成局部汇聚流，从而聚集成藏，断层的侧向遮挡作用则使得牛庄洼陷生成的油气多富集在靠近边界断层的洼陷内侧；物性较好的浊积水道微相最有利于油气的富集，朵叶体和水道间次之，外缘最差。

Main Factors Controlling Planar Enrichment of Lithologic Reservoirs in Niuzhuang Sub-Sag,Dongying Depression,Bohai Bay Basin

With the development of petroleum exploration, the importance of lithologic reservoir is becoming more and more obvious. The key to lithologic reservoir exploration is to clarify the enrichment law of hydrocarbon. A large number of lithologic reservoirs are developed in the middle third Member of Shahejie Formation in Niuzhuang sub-sag. In this study, the authors focused on the analysis of the main controlling factors on the horizontal accumulation. The results show that the distribution of oil and gas reservoirs in Niuzhuang sub-sag is controlled by three geological factors:fluid property, faults and sedimentary facies in the sub-sag. Their effects on the enrichment of lithologic reservoirs in the sub-sag are:1) the fluid migration and accumulation units control the enrichment zone of oil and gas in the plane, i.e., the north-south confluence units is favorable for petroleum accumulation, while the parallel of the north and the divergence flow units in the east and west area of the sub-sag are unfavorable; 2) the pump-absorb action of syngenetic fault makes it possible for oil and gas to form local convergent flow in the parallel or the divergence flow units developing area, thus reservoir develops; the lateral shelter action of fault makes oil and gas accumulate in the inner side of the boundary fault; 3) in all the sedimentary facies, turbidite channels with good storage quality are the best for hydrocarbon accumulation, lobe and the middle channels are the second, and peripheral areas are the worst.