庆阳深层煤成气大气田发现与地质认识  

Discovery and geological knowledge of the large deep coal-formed Qingyang Gas Field, Ordos Basin, NW China

作　　者：付金华[1,2] 魏新善[2,3] 罗顺社[4] 左智峰[5] 周虎[2,3] 刘宝宪[2,3] 孔庆芬[2,3] 战沙[2,3] 南珺祥[2,3] FU Jinhua;WEI Xinshan;LUO Shunshe;ZUO Zhifeng;ZHOU Hu;LIU Baoxian;KONG Qingfen;ZHAN Sha;NAN Junxiang(PetroChina Changqing Oilfield Company,Xi’an 710018,China;National Engineering Laboratory of Low Permeability Oil and Gas Field Exploration and Development,Xi’an 710018,China;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi’an 710018,China;Hubei Cooperative Innovation Center of Unconventional Oil and Gas(Yangtze University),Wuhan 430100,China;Exploration Department,PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]中国石油长庆油田公司,西安710018 [2]低渗透油气田勘探开发国家工程实验室,西安710018 [3]中国石油长庆油田公司勘探开发研究院,西安710018 [4]非常规油气湖北省协同创新中心(长江大学),武汉430100 [5]中国石油长庆油田公司勘探事业部,西安710018

出　　处：《石油勘探与开发》2019年第6期1047-1061,共15页Petroleum Exploration and Development

基　　金：国家重点基础研究发展计划(973项目)“淡水湖盆细粒沉积与富有机质页岩形成机理”(2014CB239003);国家科技重大专项“大型油气田及煤层气开发”(2016ZX05050,2017ZX05001002)

摘　　要：鄂尔多斯盆地西南部陇东地区经历了50年油气勘探,发现了庆阳深层煤成气大气田。通过野外地质露头、岩心观察,普通、铸体以及阴极薄片鉴定,Ro等地球化学指标、碳同位素组成、电子显微镜等配套测试分析,开展了伊陕斜坡不同埋深气藏的成烃、成储和成藏特征对比研究。庆阳深层气藏平均埋深超过4200 m,含气层位为下二叠统山西组山1段,其具有低孔、低渗、低压和低丰度“四低”特征。高热演化薄层煤源岩生烃可以形成大气田,深埋藏、高热演化晚成岩阶段仍可发育溶孔、粒间孔、晶间孔组合的优质砂岩储集层,裂缝提高了储集层渗流能力。天然气干燥系数高和负碳同位素组成系列是深层煤成气典型的地球化学特征。创新了勘探开发一体化方法,形成了“骨架直井解剖砂体、水平井集中开发”庆阳气田的经济有效开发模式。庆阳大气田的发现与成功勘探,为盆地西南部形成千亿立方米规模天然气田提供了地质依据和技术支撑,这对中国广泛分布的深层高热演化煤成气勘探也具有重要指导意义。After 50 years of oil and gas exploration in Longdong area of southwest Ordos Basin,NW China,a deep coal-formed gas field was discovered for the first time in Qingyang area.Through observation of field outcrops and core,analysis of common,cast and cathode thin sections,Ro and other geochemistry indexes,carbon isotope,electron microscope and other supporting tests and analyses,the hydrocarbon generation,reserves formation and reservoir formation characteristics of gas reservoirs at different buried depths in Yishaan slope were examined and compared.The deep gas reservoir has an average buried depth of more than 4200 m,and the main gas-bearing formation is the Member 1 of Lower Permian Shanxi Formation,which is characterized by low porosity,low permeability,low pressure and low abundance.It is believed that hydrocarbon generation in thin seam coal source rocks with high thermal evolution can form large gas fields,high-quality sandstone reservoirs with dissolved pores,intergranular pores and intercrystalline pores can still develop in late diagenetic stage under deep burial depth and high thermal evolution,and fractures improve the permeability of reservoirs.High drying coefficient of natural gas and negative carbon isotope series are typical geochemical characteristics of deep coal-formed gas.The integrated exploration and development method has been innovated,and the economic and effective development mode of gas fields of“dissecting sand body by framework vertical wells,centralized development by horizontal wells”has been formed.The discovery and successful exploration of the large gas field has provided geological basis and technical support for the construction of natural gas fields of 100 billion cubic meter scale in the southwest of the basin,and has important guidance for exploration of coal-derived gas with deep buried depth and high thermal evolution widely distributed in China.

关 键 词：鄂尔多斯盆地 上古生界 下二叠统 煤成气 深层 高热演化 庆阳大气田 

分 类 号：TE122.2[石油与天然气工程—油气勘探]