摘要 |
There is disclosed a device and a method for controlling the flow of fluid from a well bore. The device comprises a fluid control valve placed in the choke line of a well and has a shaped helical or spiral duct formed in one embodiment by a tapered screw-like plug engaging a hollow sleeve. In another embodiment, the plug is cylindrical and screw-like threads are formed in the hollow sleeve. The valve increases the degree of control over well bore pressure and flow rate as the well bore pressure fluctuates. The valve responds automatically to changes in the well bore pressure and is controlled by a control system including a hydraulic circuit and controls which visually indicate the position of the screw-like plug with respect to the hollow sleeve. The movement of the plug is controlled by the control system and the net pressure exerted on the plug by the fluid flowing through the control valve from the well bore.
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