塔西南山前地区恰探1井石炭系—二叠系重大突破与勘探前景  

Major breakthrough in the Carboniferous-Permian in Well Qiatan 1 and exploration prospect in the piedmont southwestern Tarim Basin

作　　者：王清华[1] 杨海军[1] 李勇[1] 蔡振忠[1] 杨宪彰[1] 徐振平[1] 陈才[1] 孙春燕[1] Wang Qinghua;Yang Haijun;Li Yong;Cai Zhenzhong;Yang Xianzhang;Xu Zhenping;Chen Cai;Sun Chunyan(PetroChina Tarim Oilfield Company)

机构地区：[1]中国石油塔里木油田公司

出　　处：《中国石油勘探》2023年第4期34-45,共12页China Petroleum Exploration

基　　金：中国石油天然气股份有限公司科技专项“塔里木盆地深层碎屑岩重点地区综合地质研究、目标优选、技术攻关与现场试验”(2022KT0201)。

摘　　要：塔西南山前地区西天山冲断带乌恰构造带恰探1井在石炭系—二叠系碳酸盐岩获得重大突破,标志着塔西南山前地区发现一个重要的勘探接替层系。结合区域地质资料,根据野外露头、钻井、地震等研究,以及恰探1井、昆探1井等分析化验资料的综合分析,对塔西南山前地区石炭系—二叠系的成藏条件进行再认识。研究认为,塔西南山前地区晚石炭世—早二叠世发育宽缓的“马蹄形”台缘带,形成了呈带分布的高能滩有利沉积相带,区内二叠系棋盘组发育海湾潟湖相烃源岩,厚度最大达到500m,有机质类型为Ⅰ—Ⅱ型,有机质丰度高;受沉积相带和岩溶作用双重控制,在晚石炭世—早二叠世形成裂缝—孔洞型碳酸盐岩储层,与上覆二叠系棋盘组厚层泥岩构成有利生储盖组合,进而建立了“下生上储、断裂输导、近源成藏”的油气成藏新模式。综合分析认为,该地区石炭系—二叠系断背斜圈闭成排成带分布,具有近源成藏优势,评价优选出了叶探1井、阿北1JS井等多个有利勘探目标方向,具有良好的勘探前景,可成为规模天然气勘探发现的重要接替领域。A major breakthrough has been made in the Carboniferous-Permian carbonate rocks in Well Qiatan 1 in Wuqia structural zone in the West Tianshan Thrust Belt,marking the discovery of a major replacement formation in the piedmont southwestern Tarim Basin.Combined with the regional geological data,studies on field outcrops,drilling,and seismic data,as well as the comprehensive analysis of laboratory experimental and test data in wells Qiatan 1 and Kuntan 1,hydrocarbon accumulation conditions in the Carboniferous-Permian in the piedmont southwestern Tarim Basin are re-recognized.The study results show that a“horseshoe-shaped”platform margin zone was developed in the Late Carboniferous-Early Permian in the piedmont southwestern Tarim Basin,and a favorable high-energy beach sedimentary facies zone was formed in belts,in which source rocks of bay lagoon facies were deposited in the Permian Qipan Formation,with a thickness of up to 500 m,typeⅠ-Ⅱorganic matter,and high organic matter abundance.Jointly controlled by sedimentary facies and karstification,the fractured-vuggy type carbonate reservoirs were developed in the Late Carboniferous-Early Permian,forming a favorable reservoir and cap rock assemblage with the overlying thick mudstone in the Permian Qipan Formation.As a result,a new hydrocarbon accumulation pattern of“lower source rock and upper reservoir,hydrocarbon transport by fault and near-source accumulation”is established.The comprehensive analysis indicates that the fault anticline traps in the Carboniferous-Permian are distributed in rows and belts,which have the advantage of near-source hydrocarbon accumulation,and a number of favorable exploration targets such as wells Yetan 1 and Abei 1JS are optimally selected after evaluation,showing good exploration prospects,which are expected to be the major replacement field for large-scale gas exploration and discovery.

关 键 词：塔西南山前地区 石炭系—二叠系 恰探1井 碳酸盐岩 成藏条件 

分 类 号：TE122.1[石油与天然气工程—油气勘探]