| 摘要 |
<p>A full opening subsurface control valve for use in subsurface closure of a well annulus. The valve includes a body with a sleeve reciprocably disposed in the valve body. The body is releasably attached to an upper tool string portion, and the sleeve is attached to a lower tool string portion. An actuator arm, mounted on the body and stationary with respect thereto, engages a ball valve element. When the body and sleeve are in a relatively converged position, the ball valve element is in a closed position. When the body and sleeve are in a relatively extended position, the ball valve is in an open position, such that the ball valve element, body and sleeve define a substantially unobstructed flow passage through the valve. A spring is utilized for relatively biasing the body and sleeve toward the converged position. The weight of the lower tool string portion overcomes the spring force such that the valve is maintained in an open position as it is longitudinally positioned in the well bore. A pressure balancing piston is provided for balancing forces exerted by test pressurization of the valve so that undesired opening of the valve is prevented.</p> |
