摘要：

塔里木盆地库车坳陷与塔西南坳陷的白垩系沉积厚度大，岩石类型多，既有碎屑岩，又有蒸发岩和碳酸盐岩。沉积相类型丰富，包括海相、海陆交互相和陆相，并以陆相碎屑岩沉积为主。库车坳陷与塔西南坳陷在早白垩世虽为分隔性的沉积盆地，但其陆相碎屑沉积具有几乎相同的特征：均以冲积沉积体系发育为主，相带分布和储层发育具有明显的相似性。对应山前断陷盆地的不对称性，冲积扇-扇三角洲、辫状河三角洲沉积体系发育在靠近山前的陡坡一侧，正常河流三角洲沉积体系发育在湖盆缓坡一侧。冲积扇-扇三角洲沉积体系由冲积扇、扇三角洲平原、扇三角洲前缘等构成，辫状河三角洲沉积体系由辫状河三角洲平原、辫状河三角洲前缘等构成。储层主要发育于扇三角洲或辫状河三角洲的辫状河道、水下分流河道及分流河口砂坝中，在库车坳陷和塔西南坳陷都形成了优质的储集岩。砂体厚度大，分布广，储集条件好。冲积沉积体系的普遍发育预示了白垩系储集岩在盆地内的分布可能是十分广泛的。近年在喀什凹陷、英吉苏凹陷相继取得的勘探成果大大拓宽了其勘探领域，白垩系正逐渐成为盆地内主要的勘探目的层之一，展现了良好的勘探前景。

Abstract:

The Cretaceous of the Kuqa Depression and Southwest Depression in the Tarim Basin is very thick and consists of many rock types,such as clastic rocks，evaporites and carbonate rocksThere are many kinds of sedimentary facies,including continental facies，marine facies and transitional facies，and the continental clastic facies is dominant Kuqa Depression and Southwest Depression were separated basins in the Early Cretaceous，but they had nearly the same characters of continental clastic sediments They both were mainly developed into alluvial depositional systems with an obvious similar distribution of facies belts and a similar development of reservoirCorresponding to the asymmetry of foremountain faulted basin,the alluvial fan-fan delta depositional system and the braided fluvial delta depositional system were developed at the steep slope of the lacustrine basin，and the fluvial delta depositional system were developed at the ramp slopeThe alluvial fanfan delta depositional system was composed of the alluvial fan, the fan delta plain and the fan delta front, etcThe braided fluvial delta depositional system included braided fluvial delta plain and braided fluvial delta front, etc Reservoir rocks were mainly developed in the braided channels, subaqueous distributary channels and the distributary mouth bars in fan delta or braided fluvial deltaThere are highquality reservoirs in the Kuqa Depression and Southwest DepressionThe reservoir sandbodies are thick and widely distributedThe development of alluvial depositional system indicates that the reservoirs of the Cretaceous may be extensively distributed in the Tarim BasinThe exploration achievements made in Kashi Sag and Yingjisu Sag in recent years greatly broaden the field of explorationThe Cretaceous is becoming one of the important exploration targets in the Tarim Basin, and it shows better prospect of petroleum exploration