准噶尔盆地乌-夏地区侏罗系层序地层学研究

以Vail经典层序地层学理论为基础,综合运用乌—夏地区地震、钻井和测井资料,在各层序井—震联合标定的基础上,建立准噶尔盆地西北缘乌—夏地区侏罗系层序格架,将侏罗系划分为2个超层序7个层序,并分析研究了侏罗纪不同层序的展布特征、体系域构成及沉积体系展布。乌—夏地区侏罗纪层序特征在厚度总体上呈现由斜坡区至冲断带(由南至北)厚度减薄的趋势,沉积环境早期(JSQ1—JSQ4)以较干旱的冲积扇、辫状河沉积至中期(JSQ4—JSQ5)的扇三角洲、三角洲和湖泊相类型为特征,晚期(JSQ6—JSQ7)又转变为较浅水的冲积扇、辫状河的沉积环境。

SEQUENCE STRATIGRAPHIC ANALYSIS OF THE JURASSIC STRATA IN WUXIA AREA,JUNGGAR BASIN

Based on the theory of sequence stratigraphy, utilizing seismic, drilling and well logging data, and on the basis of log and seismic combined calibration, the Jurassic strata in the Wu-Xia area of the Junggar Basin has been studied. The Jurassic strata in the Wu-Xia area can be divided into 2 supersequences and 7 sequences. The distribution of sequences systems tract composition, and sedimentary system’s distribution are analyzed. Sequence thickness gradually thins from slope area to fold-thrust zone(from south to north) in the Wu-Xia area. Sedimentary environment changed from alluvial fan、braided river, succedent fan-delta、delta and lacustrine facies,eventually to adlittoral alluvial fan and braided riverfacies. Moreover, a lithological trap of top Sangonghe Formation(JSQ4) has been forecasted in sequence framework, which has been recognized that sedimentary facies belts control sandbody of the low-stand system tracts and mudstone caprock of partial high-value areas. Below cap rocks, top sandbody can form semi-lenticular lithological trap, which has some guiding significance to explore subtle reservoir.