关键词: 库车前陆盆地, 乌什凹陷, 舒善河组, 扇三角洲, 沉积相, 储集性能

Abstract:

Based on detailed core observation，log analysis and laboratorial analysis of five wells of Wushi sag，it can be seen that the Lower Cretaceous Shushahe Formation is mainly developed in the eastern Wushi sag，which is a series of coarse terrestrial deposit，featuring redish brown sandy conglomerate with poor roundingand poor sorting. Fan delta and lake facies are the dominant types of sedimentary facies of Lower Cretaceous in the eastern Wushi sag. Debris flow deposits are common in fan delta plain subfacies，and submerged distributary channel largely develop in fan delta front. The lake was extensive and shallow，and grew shore-shallow lacustrine muddy banks and sand bars which were interbedded in the muddy banks as thin layers. The reservoir is middle\|fine lithic sandstone and features low porosity and low permeability，developing in middle Shushanhe Formation，which is mostly fan delta front sand body. The controlling factors of effective reservoir were analysized through comprehensive study on sedimentary facies and reservoir characteristics: sedimentary micro\|facies，sand grain size and interstitial material are decisive.

Key words: Kuqa foreland basin, Wushi sag, Shushahe Formation, Fan delta, Sedimentary facies, Reservoir property.