METHOD OF DECOMPOSING AND RECYCLING SPENT INVERT EMULSION DRILLING MUD Russian patent published in 2010 - IPC C09K8/34 C09K3/32 

FIELD: chemistry.

SUBSTANCE: invention relates to drilling oil and gas wells. The method involves addition of additives per 100 pts. vol of spent drilling mud, in pts. vol: a reagent based on a mixture of high dioxane alcohols 0.5-1.5; coagulant solution - aqueous ammonium sulphate solution with concentration of 100-350 g/l, 0.5-5.0; a solution of a mixture of non-ionic and ionic surface active components in organic aluminium, a solution of a mixture of non-ionic and ionic surface active components in an organic solvent 0.3-1.5. The above mentioned additives are added to the spent drilling mud successively and after addition of each additive, the mixture is stirred for not less than 0.5 hours. Further, the mixture of spent drilling mud and additive is kept for not less than 6 hours, centrifuged and the separated oleophilic phase is taken for recycling. The invention is developed in subclaims.

EFFECT: increased degree of breakdown of spent invert emulsion drilling mud due to reduction of their aggregative stability and increase of volume of the separated oleophilic phase and increased efficiency of the method of recycling the said drilling mud due to possibility of separating quality oleophilic phase i.e. suitable for repeated use when preparing process liquids for various purposes.

4 cl, 1 tbl, 2 ex