摘要
中国先后在鄂尔多斯盆地东缘、沁水盆地、滇东黔西等地区进行了深部煤层气的开发试验,虽然在提高单井产量和提升现有低产低效井产能方面取得了新进展、新突破,但尚未形成系统的、能够有效指导深层煤层气勘探开发实践的理论和技术。为此,基于鄂尔多斯盆地延川南深部煤层气田多年来的勘探开发实践,针对提高煤层气单井产量和提升现有低产低效井产能的难题,通过强化煤岩特性、裂缝延伸、气体解吸—渗流机理等基础研究的再认识,开展了大量现场储层改造攻关试验。研究结果表明:①该区煤岩天然割理裂隙发育、水平应力差异系数小,缝网足够复杂,造成强滤失,导致支撑短,井下揭示支撑主缝不足30 m,常规压裂方式难以形成长距离有效支撑裂缝是导致该区深部煤层低产、低效的根本原因;②创新提出“有效支撑”理念,即极大限度地延长高效导流通道沟通煤岩裂缝,实现主裂缝充分延伸铺砂、次级裂缝有效充填达到“远支撑”目的;③开展了“远距离运移、高效率推进、大规模铺砂”等先导工艺试验,优化形成了以“大排量、大液量、大砂量”为关键参数的有效支撑压裂技术,并在该区实现规模化应用,实施开发井33口,建成产能1.44×10^(8)m^(3),其中定向井单井稳定日产气量超过1×10^(4) m^(3),水平井单井稳定日产气量(2.5~6.0)×10^(4) m^(3),实现了深部煤层气高效开发重大突破。结论认为,“有效支撑”理念及压裂技术的工业化应用,将充分释放我国深部煤层气30×10^(12) m^(3)的煤层气资源,进一步推动天然气结构优化调整,助力我国能源结构改善。
In China,development tests of deep coalbed methane(CBM)have been successively carried out in the eastern margin of the Ordos Basin,the Qinshui Basin and the eastern Yunnan and western Guizhou area,and new progresses and new breakthroughs have been made in the improvement of single-well production rate and productivity of low-production and low-efficiency wells,but systematical theories and technologies that can effectively guide practical exploration and development of deep CBM have not been formed yet.In order to solve the difficulties in improving single-well CBM production rate and productivity of existing low-production and low-efficiency wells,this paper carries out a great number of field reservoir stimulation researches and tests by recognizing the basic researches of coal rock characteristics,fracture propagation and gas desorption-seepage mechanism,based on the practical exploration and development of deep CBM in South Yanchuan Gas Field of the Ordos Basin.And the following research results are obtained.First,in this area,natural cleats and fissures in coal rocks are well developed,the horizontal stress difference coefficient is small,complex fracture network leads to huge loss,which induces short propping.Downhole situations show that the main supporting fractures are less than 30 m.The basic reason for low production and low efficiency of deep coal seams in this area is that conventional fracturing can hardly form long-distance effective supporting fractures.Second,the concept of"effective support"is put forward innovatively,which means to extend the efficient conducting channels to the uttermost to connect coal fractures,so as to realize the sufficient extension and sanding of primary fractures and the effective filling of secondary fractures and achieve the goal of"far support".Third,pilot technological tests of long-distance migration,high-efficiency advancement and large-scale sanding are carried out,and the effective support fracturing technology with the key parameters of large displacement,large
作者
姚红生
陈贞龙
何希鹏
王运海
蒋永平
YAO Hongsheng;CHEN Zhenlong;HE Xipeng;WANG Yunhai;JIANG Yongping(Sinopec East China Oil&Gas Company,Nanjing,Jiangsu 210000,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2022年第6期97-106,共10页
Natural Gas Industry
基金
中国石化科技项目“延川南深层煤层气稳产技术研究”(编号:P19019-4)
“低压煤系气藏地质工程一体化高效开发技术”(编号:P20074-1)
“中国石化煤层气勘探战略选区研究”(编号:P21086-5)。
关键词
深部煤层气
延川南
有效支撑
压裂技术
远支撑
储层改造
高效开发
产能建设
创新实践
Deep CBM
South Yanchuan
,Effective support
Fracturing technology
Far support
Reservoir stimulation
Efficient development
Productivity construction
Innovative practice
