南苏门答腊盆地J区块中新统Gumai组岩性油气藏成藏条件及有利区带  

Hydrocarbon accumulation conditions and favorable zones of lithologic reservoirs of Miocene Gumai Formation in block J,South Sumatra Basin

作　　者：洪国良[1] 王红军[1] 祝厚勤[1] 白振华[1] 王雯雯 HONG Guoliang;WANG Hongjun;ZHU Houqin;BAI Zhenhua;WANGWenwen(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《岩性油气藏》2023年第6期138-146,共9页Lithologic Reservoirs

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“海外复杂裂谷盆地精细勘探关键技术研究”(编号:2021DJ3103)资助。

摘　　要：南苏门答腊盆地中新统Gumai组下段发育岩性油气藏。运用测井、录井、地震等资料,结合区域地质研究,对南苏门答腊盆地J区块中新统Gumai组下段砂体的成藏条件、控制因素开展了综合研究,并预测了有利区带。研究结果表明:①南苏门答腊盆地J区块油气主要来自东部Betara生烃凹陷,共发育3套烃源岩,分别为Talang Akar组下段烃源岩,Talang Akar组上段烃源岩及Gumai组烃源岩。其中,Talang Akar组下段发育的海陆过渡相烃源岩最好,以Ⅰ型或Ⅱ型干酪根为主,含大量煤层,TOC值主要为0.5%~2.0%,氢指数(HI)主要为100~350 mg/g,氧指数(OI)平均为30 mg/g。②J区块Gumai组下段自东向西发育一套三角洲近端前缘—远端前缘—前三角洲沉积体系,区块东部近端前缘以厚层砂岩为主,西部远端前缘以泥岩夹薄层砂岩为主。块状中—细砂岩为主要储集岩,泥质条带广泛发育,为三角洲前缘水下分流河道和河道溢岸沉积。③J区块Gumai组岩性油气藏主要受泥岩盖层和大断裂控制,油气多聚集于区块西部远端前缘泥岩含量高、封盖条件好的地区,且紧邻大断裂。④J区块Gumai组下段岩性油气藏具有“下生上储、复合输导、盖层控藏”的成藏模式,中部的W地区及P地区为岩性油气藏勘探的有利区。Lithologic reservoirs are developed in the lower member of Miocene Gumai Formation in South Sumatra Basin.Based on logging,mud logging and seismic data,combined with regional setting,the hydrocarbon accumulation conditions and main controlling factors of the lower member of Miocene Gumai Formation in block J of South Sumatra Basin were studied,and the favorable zones were predicted.The results show that:(1)Oil and gas in block J of South Sumatra Basin mainly come from the eastern Betara hydrocarbon generation sag,and there are three sets of source rock developed,namely,the source rocks in the lower member of Talang Akar Formation mation,the source rocks in the upper member of Talang Akar Formation,and the source rocks in Gumai Formation.Among them,the marine continental transitional source rocks developed in the lower member of Talang Akar Formation are the best,mainly typeⅠorⅡkerogen,containing a large number of coal seams.The TOC content is mainly 0.5%-2.0%,hydrogen index(HI)is mainly 100-350 mg/g,and the average oxygen index(OI)is 30 mg/g.(2)The lower member of Gumai Formation in block J developed a set of sedimentary systems from east to west,including proximal delta front,distal delta front,and prodelta.The proximal delta front in the eastern part of the block is mainly composed of thick sandstone,while the distal delta front in the western part is mainly composed of mudstone with thin sandstone.Massive medium to fine sandstones are the main reservoir rocks,with widely developed argillaceous bands,which are underwater distributary channels and overbank in the delta front.(3)The lithologic reservoirs of Gumai Formation in block J are controlled by mudstone seal and major faults.Oil and gas are mostly concentrated in distal delta front with high shale content and good sealing conditions in the western part of the block.(4)The lithologic reservoirs in the lower member of Gumai Formation in block J have a hydrocarbon accumulation model of“lower generation and upper storage,composite transport,and caprock c

关 键 词：岩性油气藏 三角洲相 盖层控藏 下生上储 海陆过渡相烃源岩 Gumai组下段 中新统 Betara生烃凹陷 南苏门答腊盆地 

分 类 号：TE122[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]