Circulating valve for wells

Abstract

A circulating (kill) valve for hot, high pressure wells includes a valve assembly to be positioned in an open-ended tubular-shaped side-pocket housing of a mandrel connected into a well tubing string. The valve assembly includes an open-ended cylindrical valve body provided with an interior sealing seat and spaced-apart side openings. A valve element is arranged within the valve body and is urged by unbalanced pressures to the open or closed position depending on the direction of the pressure imbalance. In the closed position a sealing surface on the exterior of the valve element engages and seals with the lower interior sealing seat of the valve body. A ported access to the inner well string pressure permits that pressure to urge the valve element to the closed position. Such pressure may be overcome by pressure imbalance when fluid pressure exterior of the tubing string forces the valve element upwardly from its seat. A wiper seal is arranged on the interior of the valve body and engages the outer surface of the valve element. A ported access to inner tube pressure urges the valve element to the closed position which may be overcome by pressure imbalance when exterior pressure forces the valve element from its seat.

Dependencies are inferred from the claim text.