煤层应力敏感效应的现场试验  

Field test of stress-sensitive effect in coalbed

作　　者：王梦璐 高亮 杨晓儒 张晓文 阮东 刘慧 卢德唐[1] WANG Menglu;GAO Liang;YANG Xiaoru;ZHANG Xiaowen;RUAN Dong;LIU Hui;LU Detang(School of Engineering Science,University of Science and Technology of China,Hefei 230026,Anhui,China;Well Testing Company,Xibu Drilling Engineering Company Limited,CNPC,Kelamayi 834000,Xinjiang,China;Exploration Department,Xinjiang Oilfield Company,Petrochina,Kelamayi 834000,Xinjiang,China)

机构地区：[1]中国科学技术大学工程科学学院,安徽合肥230026 [2]中国石油西部钻探工程有限公司试油公司,新疆克拉玛依834000 [3]中国石油股份有限公司新疆油田公司勘探事业部,新疆克拉玛依834000

出　　处：《实验力学》2021年第6期713-724,共12页Journal of Experimental Mechanics

基　　金：国家科技重大专项(编号:2017ZX05009005-002)。

摘　　要：排水采气是煤层气开采有别于常规天然气开发的主要特征之一。现场实际生产中的快排、慢排、憋压生产等多方面因素都会导致渗透率及裂缝形态发生变化,从而产生应力敏感效应。为研究煤层的应力敏感机制,提出多级压力测试方法,分阶段优选出排采试验制度,对某区块一口井进行现场压力恢复试井施工。采用地面电缆直读及远程无线传输方式,实现了对井底压力的实时监测,通过压力数据反演分析了煤层气储层的应力敏感性以及不同因素对储层渗透率、裂缝参数的影响。结果表明,该区块内煤层气储层具有一定的应力敏感特性。在生产过程中,地层压力、生产时间、排水速率对渗透率都有一定的影响。此外,裂缝半长也随着开采时间有所变化,与地层压力存在指数关系。在煤层气的开发过程中,制定合理的排采工作制度能够减轻应力对渗透率的伤害,节约生产成本,提高气井的采收率。Drainage gas recovery is one of the main characteristics of coalbed methane exploitation,which is different from conventional natural gas exploitation.Many factors such as faster removal,slower removal and pressure containment production in field production will lead to changes in permeability and fracture morphology,resulting in stress-sensitive effects.In order to study the stress-sensitive mechanism of the coalbed,the multi-stage pressure test method is put forward,and the drainage system is optimized in stages.One well in an example block is subjected to on-site pressure build-up test.The ground cable direct reading and remote wireless transmission methods are adopted to realize the real-time monitoring of bottom hole pressure.The stress sensitivity of coalbed methane reservoirs and the influence of different factors on permeability and fracture parameters are analyzed through the pressure data inversion.The results show that the coalbed methane reservoir in this block has stress sensitivity.During the production period,the formation pressure,the production time and the drainage rate all have influence on permeability.In addition,the fracture half-length also varies with the production time and displays an exponential relationship with the formation pressure.In the development of coalbed methane,a reasonable drainage and production system can reduce the damage to permeability caused by stress,save production cost and enhance the recovery of gas wells.

关 键 词：煤层气 应力敏感 测试优化设计 数据远程传输 压力数据反演 

分 类 号：TE373[石油与天然气工程—油气田开发工程]