吐鲁番坳陷中侏罗统沉积与储层孔隙发育特征

吐鲁番坳陷中侏罗统划分为河流相、三角洲相、扇三角洲相和湖泊相4种沉积类型。西山窑组为曲流河沉积,三间房组为三角洲相沉积,三间房七克台组为扇三角洲和湖泊相沉积。西山窑组河道砂体和三间房组三角洲前缘水下分流河道砂体的主要储集空间为溶蚀型次生孔隙,具有较高的孔隙度和渗透率。三间房七克台组扇三角洲前缘水下分流河道砂体次生孔隙不发育,孔隙度和渗透率很低。压实作用导致原生孔隙大量损失,不稳定组分的溶解则是改善孔隙结构的主要因素。

CHARACTERISTICS OF MIDDLE JURASSIC SEDIMENTATION AND RESERVOIR PORE EVOLUTION IN TURPAN DEPRESSION

Middle Jurassic Series in Turpan Depression could be divided into four facies such as river,delta,fan-delta and lake facies.The Xishanyao Formation is meandering river facies,the Sanjianfang Formation is delta facies,the Sanjianfang-Qiketai Formations contain delta and lacustrine facies deposits.The river channel sandbodies in the Xishanyao Formation and the subaqueous distributary channel sandbodies in the delta front of Sanjianfang Formation contain mainly secondary solution pores,and have high porosity and high permeability.The subaqueous distributary channel sandbodies in the fan-delta front of Sanjianfang-Qiketai Formations contain poor secondary pores,they are denes and poor reservoir bodies with low porosity and permeability.The loss of primary porosity is caused by compaction,and pore texture reformation is resulted from the solution of unstable components.