VALVE DEVICE FOR REGULATION OF WELL OPERATION Russian patent published in 1997 - IPC

FIELD: oil and gas industry. SUBSTANCE: valve device has hollow body with upper passages such as longitudinal slots and lower passages. Also provided are isolating members in the form of bellows or pistons with one of them being installed in upper part of body and creating hermetic chamber with it, and other being installed in lower part of body to create hermetic chamber. Both isolating members are rigidly connected with locking member located between rods. Diameters of isolating members are equal to or larger than diameter of locking member. With locking member in extreme upper position, area of bore opening of upper passages is less than through cross-sectional area of lower passages in body. Sealing units are installed between upper and lower passages. Throttling clearance is provided between locking member and body for equalization of pressure of medium. Lower hermetic chamber can be filled with medium which is sensible to temperature that is with medium which substantially changes its volume with temperature change. Chambers can be hydraulically interconnected through passages in rod and locking member. Device functions reliably and efficiently irrespective of changing temperature, pressure differential or flow rate of well medium. EFFECT: high efficiency. 4 cl, 3 dwg