摘要
煤层气、煤系页岩气和煤系致密气在国内外多个盆地中同时赋存,分别实现了勘探开发,但是多层/多种非常规天然气同井筒开发仍未系统实施。实现多气协同开发,将大幅提高地下资源可动用率和开发经济效益。本文系统总结国内外典型盆地煤系气生烃演化、气藏赋存、储层物性和产出机理方面的进展和认识,以期为非常规天然气多气合采提供理论和方法借鉴。主要进展包括:①煤系生烃超压或微裂缝沟通是气体运移、聚集的必要条件;②煤系含气系统呈现箱式封存、连续运聚、动态转化、定向聚散的特点;③岩层组合、应力场、温度场、含气性等静态地质参数决定可采性,单层/多层相渗、储层压力、供液能力等动态参数决定产出效果;④物理实验和数值分析可模拟理想地质条件下的合采干扰因素,储层压力和渗透率是影响排水期和气水同产期渗流的主要因素;⑤合理的排水采气工艺和科学控制采气速度,可适当避免或控制层间和井筒内的干扰。后续研究的核心是“地质+工程”甜点区优选,需要解决的关键问题包括:①叠置多类型气藏在地质演化过程的动态运聚过程,优势储层的形成与界定准则;②煤系内复杂的气水分布关系和流体压力系统,如何保证增产改造措施的有效性和科学监测;③多层合采排采控制制度及产能预测方法。在具体工作中查明“煤系沉积—储层演化—生烃运聚—气水赋存”的动态耦合过程,围绕“开发地质选区—钻完井与储层保护—增产改造—合采制度及产能预测”进行攻关。根据不同地区煤系非常规天然气的共生特点,选择合适的技术实现同井筒合采,有助于提高经济效益和资源动用率。
Coalbed methane,shale gas and tight gas within coal measures exist simultaneously in many basins worldwide,with the successful exploration and development of specific gas respectively.However,the multi-layer/multi-unconventional natural gas development in the same wellbore has not yet been systematically implemented.The realization of multi gas collaborative development will greatly improve the availability of underground resources and economic benefits.This paper systematically summarizes the development and understanding of hydrocarbon generation evolution,gas reservoir occurrence,reservoir physical properties and production mechanism of coal bearing gas occurrence in typical basins in order to provide theoretical and methodological reference for unconventional gas multi gas co-production.The main progresses include①the overpressure or micro-fissure during hydrocarbon generation of coal measures is the necessary condition for gas diffusion and migration continuously to adjacent layers;②coal bearing gas system presents the characteristics of box sealing,continuous migration and accumulation,dynamic transformation and directional accumulation and dispersion;③static geological parameters such as strata combination,stress field,temperature field and gas bearing property determine the recoverability,and dynamic parameters such as single/multi-layer phase permeability,reservoir pressure and liquid supply capacity determine the production performance;④physical experiment and numerical analysis can simulate the interference factors of combined mining under ideal geological conditions,and reservoir pressure and permeability are the main factors affecting the seepage in drainage period and gas water production period;and⑤a reasonable drainage gas production process and scientific control of gas production speed can properly avoid or control the interference between layers and in the wellbore.The key in co-production research is“geology+engineering”dessert area selection.The key problems needed to be solved
作者
李勇
王延斌
孟尚志
吴翔
陶传奇
许卫凯
LI Yong;WANG Yanbin;MENG Shangzhi;WU Xiang;TAO Chuanqi;XU Weikai(School of Geoscience and Surveying,China University of Mining and Technology,Beijing 100083,China;China United Coalbed Methane Ltd.,Beijing 100011,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第4期1406-1418,共13页
Journal of China Coal Society
基金
国家自然科学基金资助项目(41702171,U1910205)
国家科技重大专项资助项目(2016ZX05066)。
关键词
煤系气
煤系三气
合采
产层组合
共采兼容性
鄂尔多斯盆地
coal measure gas
“three gases”in coal measures
co-production
production layers combination
co-production compatibility
Ordos Basin
