塔里木盆地顺9井区志留系柯坪塔格组下段沉积特征

Sedimentary Characteristics of the Lower Members of the Silurian Kepingtage Formation in Shun 9 Region,Tarim Basin

顺托果勒低隆起志留系柯坪塔格组下段发育一套海相碎屑岩建造,是塔里木盆地一个重要的油气勘探目标及远景层位,顺9井志留系柯坪塔格组下段加砂压裂获得了低产油流,展示良好的油气勘探前景,但前人对该套含油层系沉积相类型及砂体成因认识存在巨大分歧,导致对砂体分布的刻画存在不足及盲目,制约勘探部署进程。笔者综合利用钻井岩心、测井、地震、测试分析等资料,结合沉积背景分析,对塔里木盆地顺9井区志留系柯坪塔格组下段沉积相类型及其分布进行研究,综合研究认为:顺9井区柯坪塔格组下段为以潮下带-过渡带为主的碎屑岩海岸沉积,含油砂岩段下部泥岩为浅海陆棚泥沉积;顺9井区柯坪塔格组下段含油砂岩段主要位于潮坪-浅海陆棚沉积环境的潮下带-过渡带位置,微相类型包括潮汐水道、潮汐砂坝、泥坪、陆棚砂、风暴砂体、陆架泥;储层砂体主要为潮汐水道、潮汐沙坝复合砂体,顺9及其顺903井区是有利砂体分布带。

A series of marine facies clasolite structure developed in the lower members of Silurian Kepingtage formation of the Shuntuoguole lower uplift. It is an important oil-gas exploration tar- get and a perspective position in Tarim Basin. Low-yield oil flow obtained in the way of sand frac- gence existed among predecessors about the sedimentary facies and ever, sand because of huge diver- body origin of this oil- bearing series, we could not characterize the sand distribution very well, which has already re- stricted our exploration and deployment process. In this paper, by using the data of drilling core, well logging, seismic and test analysis and combining with the depositional background analysis, we studied the sedimentary facies types and distribution of the lower members of the Silurian Kepingtage formation in Shun 9 region, Tarim Basin. We made three conclusions： first, er members of the Silurian Kepingtage formation in Shun 9 region is clasolite coastal sedi the low mentary mainly dominated by subtidal and transitional zone, the mudstone under the oil-bearing sandstone section is shallow sea shelf mud deposits; second, the oil-bearing sandstone section in the lower members of the Kepingtage formation in Shun 9 region is mainly in the subtidal and transitional zone of tidal flat and shallow sea shelf sedimentary environment, its micro-facies types include tidal channel, tidal sand dam, mudflat, shelf sand, storm sand body and continental shelf mud; last, the reservoir sand body is the recombination sand body of tidal channel and tidal sand dam~ the favorable sand body distribution belt is Shun 9 and Shun 903 well block.