1.Engineering Research Center of Coal Bed Methane/Gas Geology, Henan Polytechnic University,Jiaozuo , China;2.Collaborative Innovation Center of Coal Bed Methane and Shale Gas in Central Plains Economic Region, Jiaozuo , China;3.Shanxi Lu’an Mining Group Corporation Limited, Changzhi , China;4.Henan Ark New Energy Company Limited,Jiaozuo , China;5.North China Oilfield Branch, PetroChina Company Limited, Renqiu , China

为了进一步提高低压低渗煤储层裸眼井注入/压降测试参数的可靠性，通过对国内大量的低压低渗煤层气井注入/压降测试工艺现状和理论的分析，认为测试时间的不足是造成低压低渗储层测试结果不可靠的重要原因。通过改变注入/压降测试工艺，合理有效地延长了关井时间，提高了测试结果的可靠性。研究表明：裸眼井存在井眼事故的隐患，测试时间有限，套管井不受测试时间的限制，并且存在多种优点；针对低压低渗煤储层特性，注入时间8~12 h，合理关井时间是注入时间的7~11倍；潞安矿区30多口煤层气参数井的现场应用，验证了套管井大时长注入/压降测试技术测试结果的可靠性。

In order to further improve the parameter reliability of the injection falloff test with the open hole wells in the low pressure and low permeability coal reservoir, with the analysis on the technique present status and theory of the domestic great injection falloff tests in the low pressure and low permeability coalbed methane wells, the paper held that the insufficiency of the test time was the important cause to occur the unreliable test results from the low pressure and low permeability reservoir. With the exchanged technique of the injection falloff test and the rational and effective prolonged well closed time, the reliability of the test results was improved. The study showed that there were potential dangers of the well accidents existed in the open hole wells. The well test time was limited and the casing well was not restricted by the test time. There were many advantages existed. According to the features of the low pressure and low permeability coal reservoir, the injection time was ranging from 8～12 h and the rational well closed time was 7～11 times higher than the injection time. The site application of over 30 coalbed methane parameter wells in Lu’an Mining Area,which showed the technical test result reliability of the extending time injection falloff tests in the casing wells.