METHOD FOR PREPARATION OF HYDROCARBON PHASE OF WASTE INVERT-EMULSION DRILLING MUD AS BASE FOR PREPARATION OF PROCESS FLUIDS USED IN DRILLING AND DEVELOPMENT OF WELLS Russian patent published in 2019 - IPC C09K8/35 C09K3/32 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to drilling of oil and gas wells, in particular, to non-waste technology of well drilling. Method of preparation of hydrocarbon phase of spent invert-emulsion drilling mud for its further use as a base for preparation of process liquids used in drilling and development of wells, includes introduction into spent invert-emulsion drilling solution of non-ionic surfactant solution in organic solvent and additives, mixing of the mixture after introduction of each substance for at least 0.5 hours, holding mixture and separation in the subsequent hydrocarbon phase. Additives used are industrial water and a demulsifier based on block copolymers of ethylene and propylene oxide. Non-ionic surfactant solution in the organic solvent used is a surfactant with a hydrophilic-lipophilic balance of not less than 12, which is dissolved in concentration of 20 vol. % in an organic solvent. Said substances are introduced in the following sequence: process water, said surfactant solution and said demulsifier. After said mixing, obtained mixture is held without stirring for at least 24 hours. Said additives and solution of said surfactant are taken in the following ratio per 100 volume parts spent invert-emulsion drilling mud, fractions volume: process water 5–10; said solution of a nonionic surfactant in organic solvent 1.0–3.0; said demulsifier is 0.5–1.5.

EFFECT: technical result is possibility of extraction of high-quality hydrocarbon phase, suitable for repeated use, with simultaneous simplification of process of extraction of hydrocarbon phase from spent invert-emulsion drilling mud due to elimination of necessity to use special equipment - centrifuge, reduction of power costs.

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