| 摘要 |
In well cleaning, a cleaning fluid mixture is circulated in the well, cleaning off and removing dirt and particles of polluting matter that adhere to the interior surface of the borehole wall. Used, dirtied cleaning fluid mixture is considered to be special waste requiring aftertreatment/ disposal. The invention suggests the use of an unstable cleaning fluid mixture, that is an invert emulsion based on base oil, containing soap and a water based activating fluid, which emulsion retains its mixed nature during the well cleaning in order to ensure a good cleaning result but, in the used, dirtied condition, allows not permanently miscible phases such as oil and water to separate following a certain period of rest, e.g. a few days, in a tank or other suitable vessel - as a result of its inherent tendency to decompose - with the lighter oil phase floating on top in a reusable, non-dirty condition, and with the underlying water phase after this period of rest containing all the dirt, soap, activating agent etc. and alone constituting the special waste - in an amount less than approximately 40 volume percent of the total cleaning fluid mixture.
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