川西拗陷新场地区须二段沉积微相与砂体展布

探讨川西拗陷新场地区须家河组沉积相带演化与砂体展布特征,旨在为优质储层预测提供理论依据.基于钻测井、录井及地震资料,以新场地区须二段为例,通过对其沉积微相演化规律与砂体展布特征的系统研究,揭示砂体聚集规律,并阐明其主控因素.研究表明:须二段发育4类重点微相,以水下分流河道为主,河口坝受海平面约束间接性发育,分流河道间存...

Sedimentary micro-facies and distribution of sand bodies in the 2nd member of Xujiahe Formation,Xinchang area,western Sichuan Depression,China

Based on drilling logging,logging and seismic data,the evolution regulation of sedimentary micro-facies and the distribution characteristics of sand bodies in the 2 nd member of Xujiahe Formation(Xu 2)in Xinchang area of Sichuan Basin are systematically studied so as to unravels the accumulation regulation of sand body,elucidates its main controlling factors and provide theoretical basis for the prediction of high-quality reservoir.The results show that there are 4 kinds of key micro-facies in the Xu 2,in which the subaqueous distributary channel is dominant and exists in all stages,the estuary dam is indirectly developed under the constraint of sea level,and predelta mud micro-facies develops only at the end of the Xu 2 stage.The provenance of Xu 2 in Xinchang area is considered to be from the Micangshan-Dabashan Mountains,and the distribution of sand body is controlled by the difference of the marginal tectonic activities.In the area,the sand bodies distribute along NE-SW direction,with thickening deposition in the west section during early stage and thickening deposition in the east section during later stage.Hydrodynamic force changes frequently in each period of the 2 th member of Xujiahe Formation,which is generally manifested as the strongest sedimentary water force in the middle subsection,followed by the upper subsection,and the weakest in the lower subsection.It is proposed that the tectonic activity,eustatic change of sea and other factors control the lateral variation characteristics of sedimentary facies and sand body distribution as well as the spatial and temporal distribution of favorable reservoir sand bodies.