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准噶尔盆地吉木萨尔凹陷芦草沟组是我国近些年致密油气勘探开发的热点地区之一.本文利用岩心、岩石薄片、测井和地震等资料,在识别和分析芦草沟组主要岩石类型的基础上,对芦草沟组的沉积演化特征、层序地层格架和沉积环境的变迁等方面进行了综合研究.研究表明,芦草沟组岩性主要为碎屑岩和碳酸盐岩两个大类,其中碎屑岩以泥页岩和粉(细)砂岩为主,碳酸盐岩主要为白云岩和灰岩.沉积特征表现为:下部(F段)、中部(C+D段)和上部(A段)的泥页岩层段,发育于湖进时期的深湖至半深湖相沉积,为烃源岩层段;下部致密储集层段(E段)和上部致密储集层段(B段),发育于湖退期的浅湖相、三角洲前缘相沉积.由于后期的构造隆升,芦草沟组的沉积环境由早期的开阔湖盆逐渐向后期封闭的局限湖盆转变,沉积水体也逐渐向咸化和还原环境转变.“,”In recent years,Lucaogou Formation of Jimusar sag in Junggar Basin is one of the hotspots of exploration and development of tight sandstone oil reservoirs in China.Based on the analysis of main rock types of Lucaogou Formation,we use the cores,thin section,well logging and seismic data to comprehensively study on the sedimentary evolution,sequence stratigraphic framework,and the changes of sedimentary environment of the Lucaogou Formaiton.The study shows that the lithology of Lucaogou Formation is mainly composed of clastic rock and carbonate rock composition.The clastic rocks are mainly shale and siltstone (fine)sandstone,the carbonate rocks are mainly dolomite and limestone.The study of sedimentary characteristics shows that the lower,middle and upper parts of the mud shale segment were mainly developed in semi-deep-deep lake facies in the period of lake transgression,and the shale and mud are the main hydrocarbon source rock.The lower and upper parts of the tight sandstone were developed in the shallow lake facies and delta-front facies in the period of lake regression.Due to the late regional uplift,the sedimentary environment of Lucaogou Formation is gradually changed from the early open lake to the later limited lake,and this is also along with sedimentary water becoming more the salty and reductive.