| 摘要 |
<p>Disclosed is a safety and kill valve device useful in tubing above a packer set above a producing formation in a well, operable to shut off tubing flow and open wall flow passages to the well annulus through which heavy formation killing fluid may be pumped into the tubing. A lower ball valve is used to shut off tubing flow and an upper sleeve valve, cooperable with the ball valve, controls flow through the wall flow passage. An operating tube moves downwardly, opening the ball valve and closing the sleeve valve while compressing a spring. The compressed spring furnishes operating force to move the operating tube upwardly, closing the ball valve and opening the sleeve valve. Two embodiments operate automatically in response to higher well annulus pressures. Another embodiment may be controlled through conduit from the surface or operate automatically in response to higher annulus pressures. All embodiments may operate repeatedly without retrieving from a well.</p> |
