塔里木盆地下寒武统吾松格尔组沉积期岩相古地理与勘探意义  

Lithofacies paleogeography and exploration significance of Lower Cambrian Wusonger Formation depositional stage,Tarim Basin,NW China

作　　者：朱永进 郑剑锋[1,2] 刘玲利 冯光[4] 吴凤 闫磊[3] 张天付 ZHU Yongjin;ZHENG Jianfeng;LIU Lingli;FENG Guang;WU Feng;YAN Lei;ZHANG Tianfu(Hangzhou Research Institute of Geology,PetroChina,Hangzhou 310023,China;Key Laboratory of Carbonate Reservoir,PetroChina,Hangzhou 310023,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Tarim Oilfield Company,PetroChina,Korla 841000,China;Research Institute of Yanchang Petroleum(Group)Co.,Ltd.,Xi'an 710065,China)

机构地区：[1]中国石油杭州地质研究院,浙江杭州310023 [2]中国石油天然气集团公司碳酸盐岩储层重点实验室,浙江杭州310023 [3]中国石油勘探开发研究院,北京100083 [4]中国石油塔里木油田分公司,新疆库尔勒841000 [5]陕西延长石油(集团)有限责任公司研究院,陕西西安710065

出　　处：《天然气地球科学》2022年第1期1-12,共12页Natural Gas Geoscience

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目“海相碳酸盐岩成藏理论与勘探技术研究”(编号:2021DJ05)资助。

摘　　要：塔里木盆地柯探1井和轮探1井相继在下寒武统吾松格尔组获得高产工业油气流,突破了整体富泥的传统层系评价定位,但目前对吾松格尔组岩相古地理研究几乎为空白,制约了有利储集相带评价与预测。综合利用阿克苏地区露头资料、录井岩屑、C/O同位素曲线、测井及地震资料,分析了塔里木盆地吾松格尔组沉积期古地理格局、沉积环境及储层分布。结果表明:(1)吾松格尔组沉积期沉积充填序列及地层分布受塔南、乌恰及温宿三大台内古隆和边缘凹陷控制。古隆起区吾松格尔组超覆沉积,厚度薄,发育混积潮坪、弱镶边台地相;边缘凹陷地层齐全、厚度大,发育深水盆地相和局限潟湖相。(2)吾松格尔组沉积序列总体表现为一个完整的“海侵—海退”沉积旋回,轮南至古城地区超覆发育塔里木盆地寒武系第一套弱镶边型台地边缘,联合控制沉积期混积潮坪—局限台地的发育。(3)吾松格尔组发育台缘丘滩、礁后滩及潮上—潮间带薄层台内滩3类白云岩储集层,分布面积大。其中,主要发育于轮南—古城地区的台缘丘滩和礁后滩白云岩储层品质较高,预测面积达12070 km^(2)。以储集层预测为基础,评价认为轮南—古城地区与上覆膏盐岩盖层构成新的一套有利储盖组合且轮探1井已获突破,是下一步重点探索的有利区带。Great breakthroughs have been made in oil and natural gas exploration in Wusonger Formation of the Lower Cambrian in Tarim Basin,NW China,but there is almost no research on the sedimentary background conditions. The sedimentary paleogeographic pattern,sedimentary environment and distribution of reservoir were systematically analyzed based on outcropping data in Aksu area,logging cuttings,C/O isotopic curves,well logs and seismic data. The results indicated that:(1)The sedimentary sequence and stratigraphic distribution of the Wusonger Formation in Tarim Basin were controlled by paleo-uplift and marginal sags. The Wusonger Formation in the paleo-uplift region was over-layed with thin thickness,including mixed carbonate-siliciclastic tidal flat and weakly rimmed platform facies. The strata in the marginal sag are complete and thick,and the deep-water basin facies and confined lagoon facies are developed.(2)The sedimentary sequence of the Wusonger Formation is generally characterized by a complete“transgression and regression”sedimentary cycle.The Wusonger Formation depositional stage platform margin was recognized from Lunnan area to Gucheng area,which jointly controls the development of carbonate-siliciclastic tidal flat and weakly rimmed platform during the sedimentary period. It is the first set platform margin of the Cambrian in Tarim Basin.(3)The Wusongger Formation has types of dolomite reservoirs,platform margin mound-shoals,reef back shoal and thin-layer platform inner shoals in the intertidal zone,with large area distribution. The first two types,mainly developed in the Lunnan-Gucheng areas,are of high quality and up to 12 070 km^(2). Together with the upper Mid-Cambrian gypsum-salt rock,they form the first set of effective assemblage of the Cambrian pre-salt realm. As Well Luntan1 has obtained industrial oil-gas flow in 2020,this assemblage is considered to be favorable regions for ultradeep oil and gas exploration.

关 键 词：古隆起 混积潮坪 弱镶边台地 吾松格尔组 下寒武统 塔里木盆地 

分 类 号：TE121.344[石油与天然气工程—油气勘探]