鄂尔多斯盆地下寺湾油田北沟100井区延长组长2油层组成藏特征研究

北沟100井区位于下寺湾油田西北部,主要含油层位为三叠系延长组长2油层组,目前有采油井97口。本文以大量的岩心和测井资料为基础,结合现场的试油资料,以沉积学和油气地质学理论为指导,从储层特征、沉积微相和砂体的展布规律以及盖层的分布特征等方面深入分析了研究区长2油层组的成藏特征,研究结果表明,研究区主力油层长22-2储层岩性主要为灰色细粒长石砂岩,该时期发育的河道砂坝沉积微相为主要的砂体分布区,砂体呈北东南西向条带状展布,油层的分布与砂体的分布基本一致。根据以上的研究成果可以得出研究区油层分布主要受到沉积微相的控制,其次鼻隆带多为油藏富集的区域,以及有效盖层的分布也对油藏的分布具有重要的作用。

Study on Oil Source and Characteristics of Chang 2 Oil-bearing of Yanchang Formation in 100 Well Area of Xiasiwan Oilfied in Ordos Basin

Beigou100 well area located in the northwest of Xiasiwan Oilfied.The main oil-bearing layer was Chang 2 oil-bearing of triassic Yangchang formation.At present,there were 97 production wells.Comprehensively with utilization of drilling,logging and various analytical data,applying the sedimentary theories and being based on studying,the reservoir forming characteristics of Chang 2 oil-bearing in this area were studied from reservoir characteristics,sedimentary microfacies,the distributy law of sand-body and caprock.The study showed that,the type of the reservoir rock was gray feldspar sandstone,the sedimentary microfacies of channel sand bar developing in this period was the major sand-body distributied area which distrubitied along NE,the hydrocarbon distribution was in accord with sand-body distibution.From which we can make a summary that hydrocarbon distribution was major controlled by sedimentary microfacies,the super position part of high point of structure was the most favorable oil gas accumulation area,and the distributions of caprock were also very important to it.