METHOD OF DETOXIFYING AND REUSING PRODUCTS OF WELL BOTTOM ZONE ACID TREATMENT Russian patent published in 2005 - IPC

FIELD: oil and gas production.

SUBSTANCE: method comprises separating, in a receiving container, acid treatment products into water-in-oil-type reverse oil emulsion and acid-containing water phase. To the latter phase is added demulsifier, notably "Oksifos" in amount 0.1-1.0%. Resulting mix is agitated at temperature not below 20°C for 5-10 min with reverse-type oil emulsion at ratio 3:1 to form direct-type emulsion oil-in-water. This emulsion is settled to separate into essentially waterless oil phase and acid-containing aqueous solution of Oksifos. Oil phase is pumped out into oil-field pipeline and Oksifos solution is neutralized and simultaneously subjected to flotation removal of contaminants therefrom by way of gradually adding 5% aqueous potassium carbonate solution in amount providing achievement of pH value of Oksifos solution equal to that of local natural surface and underground waters. Thus treated Oksifos solution is used as oil-removing liquid. Further adsorption cleaning of neutral aqueous Oksifos solution is also possible by way of filtering the solution through adsorbent to obtain product that may be used as potassium and phosphorus-containing fertilizer or reused being thrown down onto relief in water-diluted state. Adsorbent is made up of a mixture crushed vegetable- and mineral-origin materials taken at 1:1 ratio, wherein vegetable-origin materials could be, in particular, peat, straw, or wood cuttings and mineral-origin materials are selected from clay, sand, or natural soil. Contaminants isolated in above-defined flotation and adsorption cleaning procedures together with work-out adsorbent are mixed with anhydrous calcium oxide at 1:1 ratio and mixed material is then used to cover process areas or to bank wells.

EFFECT: enabled pumping-out of waterless oil phase into oil-field pipeline and reuse of neutralized water phase.

5 cl, 1 dwg, 4 tbl