贝西地区南屯组扇三角洲沉积特征及地质意义

Sedimentary Characteristics and Geological Significance of Fan Delta of Nantun Formation in Beixi Area

根据岩石相、地震剖面相、测井相特征并结合岩石薄片等资料,对海拉尔盆地贝尔凹陷贝西地区下白垩统南屯组内发育的沉积体系类型及特征进行了系统的研究,认为研究区南屯组主要发育扇三角洲沉积体系,识别出了扇三角洲平原、扇三角洲前缘和前三角洲三类亚相和平原分流河道、平原分流河道间、前缘水下主河道微相等11类微相,在此基础上,建立了贝尔凹陷贝西地区南屯组的扇三角洲沉积模式,对优势储集体的预测具有一定参考价值。

According to the characteristics of lithofacies,seismic section facies and logging facies,combined with the data of thin sections of rocks,the types and characteristics of sedimentary systems developed in the lower Cretaceous Nantun Formation in Beixi area,Beier depression,Hailaer basin are systematically studied.It is considered that the Nantun Formation in the study area mainly develops fan deltaic sedimentary systems,and three types of subfacies:fan delta plain,fan delta front and front delta are identified.There are eleven microfacies,i.e.subfacies,plain distributary channel,plain distributary channel and front underwater main channel.On this basis,the fan delta sedimentary model of Nantun Formation in Beixi area of Beier depression is established,which has certain reference value for the prediction of dominant reservoirs.