联邵地区戴南组砂体展布特征及成藏研究

摘要

Based on the research of sedimentary facies,sand -body and oil reservoir analysis was carried out by more than 40 drilled wells of Dainan Formation in Lianmengzhuang and Shaobo area,Gaoyou Sag,and then the sand -body geogical model and hydrocarbon accumulation model were established respectively for these two area.The research results show that the second member of Dainan Formation (E2 d2 )developed underwater distributary channel sand -body of delta front and underwater distributary channel sand -body of fan delta front respectively in Lianmengzhuang and Shaobo area, and the sand -body distribution is fingerlike along channel extending direction,with good sand -body communication,mo-reover,hydrocarbon accumulation and enrichment are main controlled by structure,so the type of oil reservoir is structure -lithology.At the depositional stage of the 1st member of Dainan Formation (E2 d1 ),Lianmengzhuang area developed beach-bar sand -body and sedimentary sand -body affected by earthquake,and the sand body distribution is sheet -like along the strike of Hanliu fault,moreover,hydrocarbon accumulation and enrichment are main controlled by sand -body,and the type of oil reservoir is fault -lithology.Sand -body type of Shaobo area is main conglomeration,pebbled sandstone at the fan root of nearshore subaqueous alluvial fan and thin bedded siltstone at the distal fan,which were proved by drilled wells,so there are good medial fan sand -body by conjecture,which can form distal fan conglomerate shelter,and the me-dial fan sand -body is fan controlling reservoir or fault -lithology oil reservoir.According to the sand -body and hydrocar-bon accumulation model of these two area,associated with the result of seismic forecast,the well LX38 and SH20 were drilled in Lianmengzhuang and Shaobo area respectively,and they are all successful.%在沉积相研究的基础上，通过对高邮凹陷联邵地区戴南组已钻的40多口井开展砂体和油藏解剖，分别建立了两个地区的砂体地质模式和油气成藏模式。研究发现：联盟庄、邵伯地区戴二段分别发育三角洲前缘水下分流河道砂体和扇三角洲前缘水下分流河道砂体，砂体沿河道延伸方向呈指状展布，砂体连通性较好，油气成藏与富集主要受构造控制，成藏类型主要为构造－岩性油藏；戴一段沉积时期，联盟庄地区主要发育滩坝砂体及受地震影响的沉积砂体，砂体沿汉留断层的走向呈“片”状展布，油气成藏与富集主要受砂体控制，成藏类型主要为断层－岩性油藏；邵伯地区已钻井揭示砂体类型主要为近岸水下冲积扇扇根砾岩、含砾砂岩和扇端薄层粉砂岩，推测在扇根与扇端之间发育有较好的扇中砂体，可形成扇根砾岩遮挡，扇中砂体为储层的扇控型油藏或断层－岩性油藏。根据研究区建立的砂体和成藏模式，结合储层地震预测结果，在联盟庄和邵伯地区分别钻探了 LX38和 SH20井，均获得成功，取得了勘探突破。