Safety valve for horizontal completions of subterranean wells

摘要

An apparatus and method are provided relating to a safety valve for horizontal completions of subterranean wells. The apparatus is secured onto one end of a continuous length of remedial tubing which is introduceable into the well and concentrically insertable through production tubing which previously has been positioned within the well with the well having a deviated configuration including an entry portion communicating with a curved portion extending downwardly in the well from the entry portion and a generally linear end portion traversable with a production formation. The apparatus comprises a cylindrical housing and means at one end of the housing for securement of the apparatus to remedial tubing. Fluid throttling means are carried within the housing for abatement of velocity of primary fluid flow from the top of the well through the remedial tubing and the housing. Actuating sleeve means are responsive to fluid flow velocity abatement by the throttling means and are movable in a first direction to position a valve head in open position when in the generally linear end portion of the well to permit fluid to flow through the remedial tubing and the apparatus to the production formation in the generally linear end portion of the well, and movable in a second direction to position the valve head in closed position to prevent passage of fluid from the production formation of the generally linear end portion of the well through the apparatus and the remedial tubing to the top of the well. A valve means includes valve head and seat members which are carried by the housing. In a preferred form, the valve head is movable by the sleeve means to the open position and has a primary fluid flow facing surface which is covered by the sleeve when in the open position.