白音查干凹陷达尔其油田沉积相与油(气)分布

达尔其油田腾格尔组和都红木组一段具有近物源、多期次、快速沉积的特征,沉积相的类型多而复杂。勘探实践表明:该区"增储上产"的关键是寻找好的沉积微相中的优质储层。通过研究认为,达尔其地区主要发育湖泊、辫状河三角洲、冲积扇三类的沉积体系,好的沉积(微)相控下的储集层普遍具有高孔、高渗的特点,与产能具有良好的匹配关系。浅湖砂坝、席状砂、深湖浊积扇、深湖 浊积砂、辫状河水道和滑塌浊积扇是达尔其油田主力产油沉积(微)相。冲积扇~辫状河三角洲~湖泊这种过渡相沉积影响着该区油(气)分布,使达尔其油田油(气)聚集区在斜坡上呈NE-SW方向分布三个油气聚集带:高部位断背斜型油气聚集带、中部位岩性~构造型油气聚集带和低部位构造~岩性型油气聚集带,且在达尔其东区和西区油气分布各有差异。低部位构造~岩性型油气聚集带中浊积砂(扇)体、浅湖砂坝等隐蔽性油(气)藏是今后油气勘探的重要目标。

Sedimentary facies and petroleum distribution in Daerqi oilfield, Baiyinchagan sag

Tenggeer formation and the 1st member of Duhongmu formation are of the features of the fast deposits,near provenance and multiply periods in Daerqi oilfield,where they develop much and complex facies.By studying we conclude that there are three depositional system-alluvial fan,braid delta and lake.Controlled under the favorite(micro) facies,the porosity and permeability of reservoirs are high.And also the favorite(micro)facies match with paying well and middling one.So that the main force(micro) facies is shallow lascustrine sand bar,sheet sand,deep-lake fans,braided channel and slump turbidite fans.Alluvial fan-braid delta-lake,being a transitional facies,has effect on oil(gas) distribution.So that along the slope there are three petroleum zones across NE-SW: higher faulted anticline petroleum zone,middle lithologic-structural petroleum zone and lower structural-lithologic petroleum zone,of which the distribution is different in west and east area.From all above,subtle reservoir formation is the most favorite target for exploring in the lower structural-lithologic petroleum zone.