| 摘要 |
A method for releasing a stuck drill string in the borehole of an underground formation employing an non-aqueous drilling fluid, the illustrative method including contacting the stuck drill string with a non-emulsion based, homogeneous additive composition effective in reducing the annular pressure exerted by the drilling fluid or mud cake against the stuck drill string and releasing the stuck drill string, the additive composition formulated to include a mutual solvent and a viscosifying agent. In one illustrative embodiment the mutual solvent is a C2 to C22 glycol or a C2 to C22 glycol ether or mixtures or combinations of these and similar compounds known to one of skill in the art. Alternatively and preferably, the mutual solvent may be selected from the group consisting of: diethylene glycol, propoxy propanol, butyl cellosolve, butyl carbitol and mixtures or combinations of these and similar compounds known to one of skill in the art. A further illustrative embodiment includes a solid weighting agent, preferably the solid weighting agent is selected from the group galena, hematite, magnetite, iron oxides, illmenite, barite, siderite, celestite, dolomite, calcite, and mixtures or combinations of these and similar compounds known to one of skill in the art.
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