鄂尔多斯盆地中东部马家沟组盐下构造-沉积响应特征

Characteristics of structural-sedimentary response of the subsalt reservoir of Majiagou Formation in central-eastern Ordos Basin

综合利用钻井岩心、薄片、野外露头及地震解释等资料,对鄂尔多斯盆地中东部地区马家沟组五段(马五段)盐下地层进行了沉积相、地震相分析,进而探讨构造-沉积响应特征。研究表明:研究区马五段盐下发育局限台地—蒸发台地相,主要包括颗粒滩、云坪、灰坪、膏盐湖等多个沉积微相类型。利用井-震结合的方法,建立主要微相的地震相解释模式,据此对全区地震剖面进行地震相-沉积相解释,修编了马五段盐下地层岩相古地理图,认为研究区主体在马五段盐下地层沉积期呈现隆洼相间、多隆多洼的沉积格局。建立了鄂尔多斯盆地马五段盐下地层的沉积模式。

Based on the data of drilling cores,thin sections,field outcrops and seismic interpretation,the sedimentary facies and seismic facies of the Majiagou Member 5 in the central-eastern Ordos Basin are analyzed,and the structuralsedimentary response characteristics are discussed.The research shows that restricted and evaporation platform facies are developed in the subsalt strata of the Majiagou Member 5 in the study area,which can be further divided into several sedimentary microfacies types,such as granular shoal,dolomite flat,limestone flat,gypsum-salt lake and so on.The seismic facies interpretation model of main microfacies was established by using well-seismic combination method.Based on this,the seismic facies and sedimentary facies interpretation of seismic sections in the whole area is carried out,and lithofacies-paleogeographic maps are revised.It is considered that the main part of the study area in this period presents a sedimentary pattern of"uplift and depression alternating"and"multi-uplifts and multi-depression".The sedimentary model of the subsalt strata of the Majiagou Member 5 in the Ordos Basin is established.