南图尔盖盆地Kumkol油田上侏罗统库姆科尔组沉积相研究

Kumkol油田上侏罗统库姆科尔组属于中石油海外新近认识区块,为解决油田开发中遇到的地质问题,通过对大量取心井的岩心观察描述和测井、录井、岩石薄片鉴定资料等的综合分析,结合区域地质背景,对南图尔盖盆地Kumkol油田上侏罗统库姆科尔组的岩石类型、沉积构造、物源方向、古生物和沉积相特征进行了详细研究.结果表明:该区上侏罗统库姆科尔组为一套河流入湖形成的三角洲沉积,物源主要来自盆地南部,区内以三角洲前缘亚相为主,发育水下分流河道、水下天然堤、水下决口扇、河口坝等微相类型.纵向上,从J3至J2期为湖平面的上升过程,三角洲沉积的规模呈逐渐减弱的趋势.J1沉积期,湖平面相对下降,物源供应充足,为区内三角洲沉积的主要发育期,水下分流河道广泛分布.

Sedimentary facies of Kumkol Formation of Upper Jurassic in Kumkol Oilfield,south Turgay Basin

In order to solve geological problems in Kumkol Formation in Kumkol Oilfield,a lot of core data,logging data and thin section identification data are comprehensively analyzed.The rock types,sedimentary structures,provenance direction,paleontology and sedimentary facies and sedimentary developing characteristics of Kumkol Formation,the Upper Jurassic in Kumkol oilfield,South Turgay basin are studied by combining the comprehensive analysis results with the regional geology background.It is shown that,Kumkol Formation in the studied area is a set of delta deposition formed by river flowing into lake.The provenance is mainly from the south of South Turgay Basin.Delta front subfacies is main sedimentary facies in this area,including a series of microfacies such as subaqueous distributary channel,subaqueous levee,subaqueous crevasse splay,river mouth bar.From J₃ to J₂ period was the rising process of lake level,and the size of the delta deposition presents weakening tendency.In J₁ period,the lake level declined relatively with abundant provenance.The period is the mainly developing period of the delta deposition and the subaqueous distributary channels distribute widely.