摘要
我国深部煤层气资源潜力大,占总资源量的62.8%,但实现有效开发面临强非均质性、高地应力、工艺配套难、产能低等诸多挑战。以延川南深部煤层气田为例,依据“沉积控煤、构造控藏、水动力控气、地应力控渗、物性控产”五要素,将关键参数进行叠加,精细划分气田开发地质单元,厘清各开发地质单元关键地质属性、开发制约条件,并制定了差异化的开发对策;形成针对层内阻塞、近井地带结垢、深部煤层难改造、高液量难降压等不同低效主因的治理对策和适用于深部煤层气复杂地质条件下“疏导解堵、扰动增透、有效支撑、提液降压”的增效技术系列。在此基础上,提出了一整套基于“多要素耦合气藏控制单元”的地质工程一体化增效思路和工艺技术:以提高资源动用程度为核心,针对高产区煤粉阻碍渗流通道而造成的气井递减,采取“氮气扰动”形成压力波扰动而解决层内疏通,21口井见气效率90%,单井日增产气量400 m^(3);深部煤层矿化度高易在近井筒地带结垢是导致低产的重要因素,通过实施可控冲击波破裂增透解除堵塞,单井日增产气量达850 m^(3);以实现高应力区资源有效动用为目标,通过“长距离有效支撑、大规模体积改造”以达到深部煤储层有效改造,实现难动储量效益开发,实施16口井全部见效,单井日增产气量1500 m^(3),产气水平提升5~6倍;同时在高产液低效井中持续挖潜,采取提液降压效果初步显现。一体化增效关键技术体系的研发成功,为国内深部煤层气效益开发起到了带动和示范作用。
Deep coalbed methane resources have great potential,accounting for 62.8%of the total resources.However,effective development faces many challenges such as strong heterogeneity,high geostress,difficult process matching and low production capacity.Taking the deep coalbed methane in Southern Yanchuan Block as an example,the key parameters are overlaid and analyzed,the development geological units of the gas field are finely divided according to the five controlling factors of“sedimentation coal-control,tectonic influenced accumulation,hydrodynamic gas-control,geostress seepage-control,physical property production-control”.The key geological attributes and development constraints of each development geological unit are clarified,and the differentiated development countermeasures are formulated.It has formed a series of treatment countermeasures for different main causes of low efficiency,such as blocking in the formation,scaling near the well,difficult transformation of deep coal seam,high fluid volume and difficult pressure reduction,and a series of efficiency increasing technologies suitable for“dredging and plug removal,disturbance and permeability enhancement,effective support,liquid extraction and pressure reduction”under complex geological conditions of deep CBM.On this basis,a set of geological engineering integration and technology based on the geological attribute of“multi element coupling gas reservoir control unit”is proposed.In view of the decline of gas wells caused by coal powder blocking the seepage channel in high-yield area,the“nitrogen disturbance”is adopted to form pressure wave disturbance to solve the problem of inner layer dredging.The water breakthrough efficiency of 21 wells is 90%,and the daily increase of single well is 400 m^(3).It is recognized that the high mineralization degree of deep coal seam is easy to scale in the near wellbore area,resulting in low production.In order to realize the effective utilization of resources in high stress area,the effective transformation of deep coal reservoir is achieved through“long-distance effective support and large-scale volume transformation”.All the 16 wells have achieved good results,and the daily increase of single well is 1500 m^(3),and the gas production level is increased by 5-6 times.Meanwhile,the potential of high-yield and low-efficiency wells is continuously explored,and the effect of fluid lifting and pressure reduction is initially shown.The successful research and development of the key technology system of integrated efficiency enhancement has played a leading and exemplary role in the cost-effective development of deep coalbed methane in China.
作者
陈贞龙
CHEN Zhenlong(East China Oil&Gas Company,SINOPEC,Nanjing 210011,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2021年第2期13-20,共8页
Coal Geology & Exploration
基金
国家自然科学基金重点项目(41530314)
中国石油化工股份有限公司重点科技项目(P20074-1)
中国石油化工股份有限公司科技项目(P19019-4)。
关键词
深部煤层气
延川南
地质工程一体化
多要素耦合
效益开发
低产增效
deep coalbed methane
Southern Yanchuan Block
geological engineering integration
multi-factor coupling
cost-effective development
efficiency enhancement