东濮凹陷文东—前梨园地区沙三段、沙四段沉积特征和有利储集体预测

The sediment of Es_3 and Es_4 Member and prediction of favorable reservoir in the Wendong-Qianliyuan Area, Dongpu Depression

运用现代沉积学、层序地层学理论,根据对岩心、测井、地震资料的分析,划分出东濮凹陷文东—前梨园地区沙三段、沙四段的4种沉积体系,即湖泊三角洲体系(一般三角洲、扇三角洲)、湖泊体系、冲积扇和重力流体系;沉积体系的时、空演化可分为3期:Es4期(初始裂陷阶段)、Es43期(快速裂陷阶段)、Es33—Es31期(衰减断陷阶段);沉积体系的时空演化反映了湖水浅→深→浅的变化过程和受控于构造影响的特征。研究结果,该区隐蔽油气藏的有利勘探目标主要是:东侧扇三角洲砂体与鼻状构造、扇三角洲远端砂体与上倾尖灭圈闭、湖泊三角洲前缘砂体与断块圈闭、冲积扇砂体与上倾尖灭圈闭和重力流、滨岸砂坝砂体类岩性圈闭。

Based on modern of sedimentology and sequence stratigraphy, and analyses of cores, logging and seismic information, four sedimentary systems are identified in the Wendong-Qianliyuan Area, including lacustrine delta system (delta, fan delta), lake system, alluvial fan and gravity flow system. The time-space evolution of Es_(3) and Es_(4) could be divided into 3 stages: Es_(4) (starting stage), Es_3~4 (fast stage) and Es_3~3-Es_3~1 (decline stage).The study shows that the favorable reservoirs are fan delta sand body and nose structure, front sand body of fan delta and tip-out trap, sand body of lacustrine delta-front and fault-block trap, alluvial fan sand body and tip-out trap, gravity flow, shore bar and lithological trap.