| 摘要 |
<p>A method of clearing well casing or tubing from a target region of an oil/gas well borehole involves employing chemical agents 9 that consume, weaken or melt the well casing/tubing. The chemical 9 may be thermite. The well casing may be cleared to expose the rock formation within which the well borehole is formed so that the rock formation can be accessed from within the well casing/tubing. In other aspects of the method of removal of inner tubing structures is used to facilitate the unimpaired deployment of repair tools down the well borehole. The tubing may be weakened by perforating prior to clearing. In another aspect a region of tubing may be subject to a rapid temperature change to embrittle or weaken the tubing prior to applying a physical or environment stress to the tubing before it is cleared.</p> |
