油藏地球化学在沈家铺断块油田的应用

Application of reservoir geochemistry in the Shenjiapu Faulted Block Oilfield

首先采用色谱、色谱-质谱等分析技术研究了本区枣Ⅴ油组原油地球化学特征及断块间油藏流体连通性,然后利用岩石热解(Rock-Eval)和薄层色谱-火焰离子检测技术(TLC-FID),结合试油及测井资料,建立了枣Ⅴ油组油干水层划分的地球化学标准,研究了流体(原油)及其性质在纵向上和平面上的变化及分布规律。研究结果表明,枣Ⅴ油组原油为低成熟原油,其源岩形成于微咸水—半咸水湖相还原环境,主要由菌藻类有机质组成,但某些藻类可能是其源岩有机质的主要贡献者;枣Ⅴ油组断块间油藏流体不连通;纵向上,储层流体非均质性强,总体而言,随深度增加枣Ⅴ油组储层含油性逐渐变差,但原油性质逐渐变好。平面上,储层流体非均质性强,不同断块含油性不同,同一断块不同部位含油性不同;不同断块原油性质不同,总体而言,从NE到SW,枣Ⅴ油组的原油性质逐渐变好。

The geochemical characteristics of oil and reservoir fluid continuity b etween faulted blocks are studied using GC and GC-MS techniques in the Z ao V oil measures of the Shenjiapu oilfield.Geochemical criterion of identifying the oil,water and dry la yers is built,and vertical and horiz ontal variations of reservoir fluid(crude oil)contents and its property is analyze d using Rock-Eval and TLC-FID techni ques,combining with the well testin g results and well logging data in this paper.The results show that the oil belongs to low-mature oil,its source rock formed in slight saline to saline red uctive lake depositional environme nt,and is composed of bacteria and algae,even the later is perhaps the main con tribution of organisms.Reservoir f luids between fault blocks are not continuative.Vertically,reservo ir fluids vary drastically,that is,in general,reservoir oil content ra te decreases with increasing depth,however,oil property become better with increasing depth.Reservoir fluids vary dra stically in the plane,that is,different faul t blocks have different oil content r ate,even different parts of the same faulted block have also different oil conten t rate.Oil property is different in d ifferent faulted blocks,on the whole,oil property become better from northea st to southwest horizontally.