井口多功能套管气回收装置的研制与应用

Development and Application of Multi-Function Casing Gas Recovery Device at Wellhead

针对常规定压放气阀冬季冻堵,回压较高流程井组,低压套管气无法有效回收等问题,利用负压及热交换原理,创新设计了一种井口多功能套管气回收装置,解决回压高于套压井组套气无法回收,冬季低温冻堵的现象,提高了井口套气回收量及井口密闭集输水平。利用抽油机下行过程中压力降低的现象,在套管气回收装置前端设计地面管线流体防倒流装置,阻断了地面管线回压与套管气回收装置之间的压力传导,套管气回收装置套气入口端形成负压区,降低了套气回收的压力门槛,有利于套管气的回收,解决高回压井套气回收问题。同时将套管气回收装置活动元件设计在液流中间,最大限度地保证套管气回收装置活动元件与采出液进行热交换,提高了井口多功能套管气回收装置运行温度,解决了冬季低温冻堵的现象。

In view of the problems, for example, freezing and blocking of conventional constant pressure vent valve in winter, well group with high back pressure, and low pressure casing gas cannot be effectively recovered, a multifunctional wellhead casing gas recovery device is innovatively de-signed based on the principle of negative pressure and heat exchange, which solves the problem that the casing gas cannot be recovered when the back pressure is higher than the casing killing group, and the phenomenon of low temperature freezing in winter is solved, and the recovery amount of wellhead casing gas and the level of wellhead closed gathering and transportation are improved. Based on the phenomenon of pressure drop in the process of pumping unit descending, the anti backflow device of surface pipeline fluid is designed in front of casing gas recovery device, which blocks the pressure conduction between the surface pipeline back pressure and the casing gas recovery device. The negative pressure zone is formed at the casing gas inlet end of the casing gas recovery device, which reduces the pressure threshold of casing gas recovery, which is condu-cive to the recovery of casing gas and solves the problem of casing gas in high back pressure wells recycling issues. At the same time, the movable element of the casing gas recovery device is de-signed in the middle of the liquid flow to ensure the heat exchange between the movable element of the casing gas recovery device and the produced liquid to the maximum extent, which improves the operating temperature of the multifunctional casing gas recovery device at the wellhead, and solves the phenomenon of freezing and blocking at low temperature in winter.