中国海相油气田勘探实例之十六 四川盆地元坝大气田的发现与勘探  

Cases of Discovery and Exploration of Marine Fields in China(Part 16):Yuanba Gas Field in Sichuan Basin

作　　者：郭旭升[1] 郭彤楼[1] 黄仁春[1] 段金宝[1] 

机构地区：[1]中国石油化工股份有限公司勘探分公司

出　　处：《海相油气地质》2014年第4期57-64,共8页Marine Origin Petroleum Geology

基　　金：国家科技重大专项下属课题"南方海相碳酸盐岩大中型气田富集规律与勘探评价"(编号2011ZX05005-003)资助

摘　　要：元坝气田是目前我国探明的储量规模最大、埋藏最深的生物礁气田。气田发现于2007年,至2013年底累计探明储量2 086.92×108 m3。元坝气田是由多个礁滩岩性圈闭组成的大型圈闭群,圈闭的总含气面积为286 km2,主要含气层段为上二叠统长兴组礁滩相白云岩和白云质(含白云质)灰岩,气藏埋深约7 000 m。生物礁具有"早滩晚礁、多期叠置、成排成带"的发育特征。烃源岩主要为上二叠统吴家坪组(龙潭组)及大隆组泥岩和泥灰岩。盖层为中—下三叠统嘉陵江组—雷口坡组膏盐岩和泥岩。气田经历了早期岩性油藏、中期深埋裂解和后期抬升改造的复杂成藏过程。论述了气田的发现和勘探过程以及气藏的基本地质特征,总结了它对我国超深层碳酸盐岩和成熟盆地油气勘探的启示。Yuanba Gas Field is a large biohermal gas field with the largest scale of reserves and the largest buried depth in China at present. It was discovered in 2007 and it possesses 208.692×10^9m^3 of the proved gas reserves in-place till to the end of 2013. This field is composed of a large-scaled group of reef-shoal facies lithologic traps with a total covering area of 286km^2. The predominant gas-bearing reservoir consists of the Upper Permian Changxing reef-shoal facies dolostone and dolomitic limestone. The reservoirs are buried deeply to about 7000m. Development of reefs is characterized by “early shoal and late reef facies sedimentation and multi-phased overlaps in rows or belts”. Hydrocarbon derives from the Upper Permian Wujiaping （or Longtan） and Dalong mudstone and marlstone. The cover is the Middle-Lower Triassic Jialingjiang-Leikoupo gypsum salt rock and mudstone. This field experienced a complicated process of hydrocarbon accumulation in which the reservoirs were lithologic in the early stage, deep-buried and hydrocarbon cracking in the mid-term stage and uplifting and reformed in the late stage. Besides the geological characteristics of gas reservoirs, the field history of discovery and exploration are concluded, which is revelaton/to the exploration of ultradeep carbonate reservoirs and mature basins.

关 键 词：四川盆地 元坝气田 海相地层 飞仙关组 长兴组 气藏特征 油气勘探史 勘探启示 

分 类 号：TE132.1[石油与天然气工程—油气勘探]