东营凹陷沙三段—沙一段层序地层与油气

Relationship between sequence stratigraphy and hydrocarbon accumulation in Es_3 -Es_1 of the Shahejie Formation,Dongying Sag

综合地震、测井、钻井等资料分析 ,东营凹陷沙三段至沙一段可划分为 4个三级层序。层序 1(沙三下亚段 )和层序 2(沙三中亚段 )为T R型层序 ,由湖进域 (LTST)和湖退域 (LRST)组成 ;层序 3 (沙三上亚段—沙二下亚段 )和层序 4(沙二上亚段—沙一段 )为四分层序 ,由低位域、湖侵域、高位域和下降域组成。T R层序的湖退域砂体发育 ,也易形成油气藏 ;湖进域砂体发育很少 ,但砂体具有良好的成藏条件 ,极易形成岩性油气藏。四分层序的层序界面附近砂体发育 ,但砂体往往缺乏好的圈闭条件 ,成藏概率较低。图 3参

On the integrated analyses of the seismic, well logging and well drilling data, Es 3 Es 1 in the Shahejie Formation of Dongying Sag can be divided into four 3rd order sequences. Sequence 1 (the lower part of Es 3 ) and Sequence 2 (the middle part of Es 3 ) are T R sequences, which are composed of lacustrine transgressive system tract (LTST) and lacustrine regressive system tract (LRST). Sequence 3 (the upper part of Es 3 to the lower part of Es 2 ) and Sequence 4 (the upper part of Es 2 to Es 1 ) can be divided into four tracts, such as LST, TST, HST and FSST. The sandbodies of LRST in a T R sequence were not only developed well, but also were easy to form reservoirs. The sandbodies of LTST developed poorly, but they were easy to form lithologic reservoirs. The sandbodies nearby the four tracts mentioned above developed well, but they have little possibility of forming reservoir because of the poor trapping conditions.