煤层气井产气量控制因素分析

结合沁水盆地东北部和顺区块煤层气井排采经验，分别从地质因素（构造位置、陷落柱、断层等）、工程因素（水力压裂的缝高控制、裂缝半长等）和排采因素（排液速度、套压控制、停电停抽等）三个方面探讨了该区块煤层气井产气量的控制因素。研究发现：该区块煤层气井产气量受构造位置的影响较大，与陡坡带的距离和煤层含气量呈现明显的相关性；区块高构造部位水力压裂易出现压开含水层及井间压窜现象；见气时套压的控制与产气量具有一定规律，套压小于0.5 MPa 开井产气，效果最差，套压0.51.0 MPa 开井产气，效果次之，套压大于1.0 MPa 开井产气，效果最好。

Controlling Factor Analysis of Gas Production Rate in Coal Bed Gas Well

With consideration of experience of discharge water and gas production in coal bed gas wells,Heshun block in northeastern Qinshui Basin,we study controlling factors of gas production rate in coal bed gas well in this block from following aspects:geologicalfactors(structurallocation,swallowpillarandfaultetc.),engineeringfactors(controllingoffractureheight of hydraulic fracturing,half length of fracture and etc.)and discharge water and gas production factors(rate of delivery,casing pressure controlling,power off and stop production and etc.).The conclusions can be drawn:first,gas production in coal bed gas well is controlled by structural location to large extent.Second,distance between well and actic region and gas content in coal bed are correlative apparently.Third,hydraulic fracturing in higher structural location is easily subjected to fracturing pay zone and communication between wells.Fourth,when gas break through,controlling of casing pressure and gas production rate have some rules.When casing pressure is less than 0.5MPa,the effect is worst;when casing pressure is between 0.5 MPa1.0MPa,theeffectbetter;whencasingpressureisgreaterthan1.0MPa,theeffectisthebest.Accordingtotheresearchresults,strategies and advice are put forward to guide future work on the block,which we hope to contribute to future exploration and development of coal bed gas.