煤层气直井排采捞煤粉一体化技术

Technology of integrating drainage, gas production and coaldust bailing for coalbed methane vertical wells

在煤层气井开采过程中,目前用的最多的还是抽油机排采系统,在排采泵方面主要采用常规整筒泵,这种泵所存在的主要问题是煤粉卡泵和煤粉卡固定阀、游动阀,导致系统频繁作业,严重影响了煤层气的开采时率。为了有效解决这个问题,研制出一套排采捞煤粉一体化管柱,该管柱采用新型防煤粉泵和挂篮式沉砂管,使煤层气井的排采、捞砂一体化成为可能。新型防煤粉泵采用了高支固定阀和大直径游动阀的长柱塞结构,不仅可以有效防止煤粉卡固定阀、游动阀,还能有效防止煤粉进入泵筒造成卡泵;排采过程中沉积下来的煤粉进入挂篮式沉砂管中,待到检泵时连同沉积在沉砂管中的煤粉一同起出,取消了捞煤粉环节,节约成本。现场应用表明,煤层气直井排采捞煤粉一体化管柱适应现场需求,延长了检泵周期,具有良好的推广前景。

During extraction of coalbed methane well, the most used method is pumping unit discharge and extraction system. The conventional mono-barrel pump is usually used as the discharge and extraction pump;the main problem of this pump is that pump is stuck by coal dust with standing valve and traveling valve are also stuck by coal dust, leading to frequent operation of the system and severely affecting the production efifciency of coalbed methane. In order to effectively solve this problem, a set of string integrating dis-charge, extraction and bailing of coal dust has been developed, which uses new coal dust-proof pump and basket settling pipe, making it possible to integrate discharge, extraction and sand bailing in coalbed methane wells. The new coaldust-proof pump utilizes long plunger structure with highly standing valve and large-diameter travelling valve, which cannot only effectively prevent coaldust from sticking the standing valve and travelling valve, but also effectively prevent coaldust from entering pump barrel and causing stuck pump. The coaldust deposited during discharge and extraction goes into the basket sand setting pipe, which will be removed together with coaldust deposited in the sand setting pipe during pump inspection, diminishing the work of bailing coaldust and saving the cost. Field applica-tion shows that the pipe string integrating coalbed methane discharge, extraction and coaldust bailing by vertical well can meet the site requirement, extend the pump inspection cycle and has good promotion prospect.