防止清蜡热液渗入地层的新型井下阀装置

New downhole valve assembly for preventing paraffin removal hot fluid entering into formation.

防止清蜡热液渗入地层的新型井下阀装置主要由阀门、阀座、活塞、弹簧和连杆等组成。整个装置接在丢手封隔器下端，由井筒中清蜡热液液柱压力自动控制关闭与打开。热洗清蜡开始，当油套管环空液面升到一定高度时，阀门关闭；热洗结束后，当环空液面降到一定高度时，阀门打开。阀通径大，生产时井液阻力小，在保证井中液柱高度小于使阀关闭时的液柱高度时，井下工具或仪器可通过阀下入井中。

The valve assembly herein discussed is mainly composed of valve,valve seat,piston,spring and pull rod.It is attached to the bottom end of a retrievable packer,and opens and closes automatically with the change of the pressure of the hot fluid column in the tubing-casing annulus.It clcoes when the fluid level in the annulus ascends to a certain height at the beginning of hot oiling, and opens when the fluid level descends to a certain level at the end of hot oiling.The valve has large internal diameter,therefore downhole tools and instruments can be tripped into the hole through the valve when it is opened.