Efforts were made to develop effective technologies to break stable water-in-oil emulsions stabilized by solid particles. The paper presents the results of the research studies. Based on the laboratory research, a number of technologies have been developed for breaking of stable water-in-oil emulsions and obtaining of on-spec oil with water cut up to 1 %, iron sulfide content up to 200 mg/dm3, and solids content up to 0.1 %wt. The technology of thermochemical treatment involves circulation of stable water-in-oil emulsion in the process loop, heating, diluting, and adding chemical agents. The technology of acid treatment involves circulation of stable water-in-oil emulsion in the process loop, heating, and adding acid. The technology of stage combined treatment combines the technology of thermochemical treatment at stage one, using diluents and chemical agents, and the technology of acid treatment at stage two, using acid.
The technologies of acid treatment and stage combined treatment were tested at the Tatneft PJSC battery. The test was very successful: more than 90% of oil contained in the feed water-in-oil emulsion was recovered. The economics of the process was also attractive. Commercialization of these technologies will allow the Company to cut down expenses related to emulsion disposal services of outside companies; also the volume of additional on-spec oil will be increased.
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