抽油机井自控式套管气回收装置

为了有效收集低套压抽油机井的套管气,研制了一种自控式套管气回收装置。该装置排液缸连接生产阀门,气缸通过进气管连接套管阀,两缸活塞通过连杆连接,利用抽油机井上下冲程时井口压力变化实现气缸强制吸入套管气。上冲程时排液缸压力上升,活塞右行,气缸容积增大,压力降低,完成套管气吸入;下冲程时井口压力下降,在集油管线压力下使气缸活塞左行,气缸内套管气进入排液管,如此往复循环,整个工作过程不需要额外动力,可以将套压低至0.1 MPa的油井套管气有效回收。现场应用22口井,平均日回收天然气1 352 m3,有效提高了天然气资源利用率。

Autocontrol casing gas recovery unit for pumping wells

In order to effectively gather the casing gas from pumping wells with low casing pressure, an autocontol casing gas recovery unit has been developed. The drainage cylinder of this unit is connected to the production valve and the air cylinder is connected with casing valve through the inlet tube. The two-cylinder piston is connected through the connecting rod so that the air cylinder draws in casing gas forcibly by changes of wellhead pressure during up-down stroking in pumping wells. At up stroke, the pressure in drainage cylinder increases, the cylinder piston moves to the right, so the capacity becomes larger, pressure decreases and the casing gas is drawn in. At down stroke, the wellhead pressure decreases and air cylinder piston moves to the left under the pressure gathering pipeline, so the casing gas in air cylinder flows into the drainage pipe. This cycle repeats and the no additional power is needed in the entire working process, so the casing gas in oil wells where casing pressure is reduced to 0.1 MPa can be recovered effectively. This unit has been used in 22 wells and daily gas recovery rate is 1 352 m3 in average, which has effectively increased the utilization rate of natural gas resource.