辽东湾辽中凹陷中部古近系东营组震浊积岩特征研究

辽东湾辽中凹陷中部古近系东营组地层中发育多期大规模浊积扇,利用岩芯、薄片、测井及地震资料,对这些浊积岩及其下伏地层的沉积成岩特征、沉积构造和岩石类型分析,认为研究区东营组浊积岩与典型的原地震积岩伴生,属于地震成因的浊积岩.这些浊积扇的扇中以长石砂岩和岩屑长石砂岩为主,埋深一般在1 500 m～2 500 m左右,为早成岩演化Bl期.测井解释孔隙度平均为27.5%,储层物性良好,并且具有良好的生储盖组合,钻探证实其良好的含油气性.此类浊积扇与地震活动紧密相关,其分布具有一定的等时性,因此可以推测渤海海域郯庐断裂两侧在活跃期发育的大规模浊积扇,具有良好的岩性油气藏勘探前景.

STUDY OF CHARACTERISTIS OF PALEOGENE SEISMOTURBIDITE IN THE CENTRAL LIAOZHONG DEPRESSION,LIAODONG BAY

Large-scale Paleogene turbidite fan of multiple stages is developed in the Dongying Formation of central Liaozhong depression,Liaodong bay.In this paper,the sedimentation and diagenesis characters,sedimentary structure and rock types of turbidite and underlying layer are analyzed by using cores,slice,well-logging and seismic data.It is believed that the turbidite in Dongying Formation is associated with typical seismoturbidite and is induced by earthquake.The middle of the turbidite fan is dominated by arkose and lithic arkose,with burial depth of 1 500 m~2 500 m,and was fell under early diagenetic B1 stage.Well logging interpretation reveals that the average porosity is 27.5%.The physical property of reservoir is of good,with favorable source-reservoir-cap assemblage.Well drillings further proves that its oil bearing property is satisfactory.This kind of turbidite fan is closely related with earthquake and distributed isochronously in some degree.So it can be inferred that large scale turbidite fan is developed in the centre of the lake basin at both sides of the Tanlu fault in Bohai area during active fracturing period.