鄂尔多斯盆地什社地区长3油层组沉积相研究

Study on the Sedimentary Facies of Chang 3 Reservoi in Shishe Area of Ordos Basin

鄂尔多斯盆地西南部为重要的石油产出区域,盆地西南部什社地区长3油层组是重要含油气勘探目标层位之一。目前,对研究区长3油层组沉积环境的研究成果较少,沉积相的划分一直存在争议。基于对露头剖面和岩心的观察描述,结合测井、钻井等资料,运用沉积学、古生物学及地球物理测井等理论知识,通过岩心相与测井相的综合对比分析来确定什社地区长3油层组沉积微相类型与特征,探讨沉积演化过程。结果表明,鄂尔多斯盆地什社地区长3油层组为三角洲平原和三角洲前缘沉积,主要发育分流河道、水下分流河道、分流间湾、沼泽等沉积微相。多期河道砂体相互叠置构成研究区储层的主体骨架。

The southwest of Ordos Basin was an important oil producing area,and the Chang 3 oilbearing formation was one of the important oil and gas exploration targets.There were few studies on the sedimentary environment of Chang 3 Reservoir,and the determination of sedimentary facies has been controversial.Based on the observation and description of outcrops and cores,combined with logging and drilling data,by using sedimentology,paleontology and geophysical logging and other knowledge,through the comprehensive contrast of cores and logging,the sedimentary microfacies types and characteristics Chang 3 Reservoir were clarified.The evolution of the sedimentary facies of Chang 3 Reservoir was studied by establishing the single well facies and continuous well profile,and the distribution of sedimentary microfacies.The results show that the Chang 3 Reservoir in Ordos Basin is mainly composed of delta plain and delta front,including distributary channel,underwater distributary channel,interdistributary bay,swamp and so on.The main framework of the Chang 3 Reservoir is formed by overlapping of multi channel sand bodies.