| 摘要 |
<p>A tool for use in a testing string disposed in a well bore. The tool comprises a tubular housing defining a longitudinal tool bore; a valve disposed in the housing including a sleeve valve for controlling communication between the tool bore and the exterior of the housing, and a tool bore closure valve. A device is also provided to selectively open and close either the sleeve valve or the tool bore closure valve while the other remains inoperative in response to sequential changes in pressure proximate the tool in the well bore.</p> |
