塔里木盆地顺北地区三叠系沉积相及沉积模式研究

STUDY OF CHARACTERISTICS OF TRIASSIC SEDIMENTARY FACIES AND DEPOSITIONAL MODEL IN THE NORTHERN SUNBEI REGION,TARIM BASIN

塔里木盆地三叠纪进入前陆盆地发展阶段,该地区油气资源丰富,但整体勘探和研究程度低,对该地区三叠系进行研究具有重要的理论意义和实际意义。利用S8井岩芯资料、岩芯样品50余块、岩石薄片100张、30余口钻井、测井资料,并结合二维44条地震测线、三维地震(1300 km^2)资料解释,对塔里木盆地顺北地区三叠系沉积相特征进行研究,根据该研究区沉积特点,将其分为三角洲和湖泊沉积相,进一步识别出水下分流河道、分流间湾、浅湖砂坝和浅湖泥四种微相。三角洲水下分流河道方向为由北向南,受北部沙雅隆起隆升强弱的影响,水下分流河道发育规模具有弱(柯吐尔组)-强(阿克库勒组)-弱(哈拉哈塘组)的演化特征。以上述沉积演化特征为基础,建立了顺北地区三角洲-湖泊的沉积模式。

Tarim Basin experienced foreland basin development in the Triassic Period involed in the enrichment of oil and gas resources.Based on the research of Shun 8 drilling well,core samples,thin sections,drilling and logging data,44 seismic logging lines and three-dimensional seismic(1 300 km^2) data interpretation,the characteristics of Triassic sedimentary facies in Shunbei area of Tarim Basin are studied.According to the sedimentary characteristics of the study area,the sedimentary facies can be classified into delta and lacustrine sedimentary facies,which can be further subdivided into such microfacies as underwater distributary channe, distributary bay,shallow lake sand dam and shallow lake mud.The underwater distributary channel in the delta is affected by the uplift of the northern Shaya uplift and extends from north to south.The development scale of the underwater distributary channel has the evolutional characteristics of from weak(Ketur Formation) to strong(Akekule Formation) to weak(Halahatang Formation).A deltaic lake depositional model has been established on the basis of comprehensive analysis of sedimentary evolution characteristics in Shunbei area of Tarim Basin.