PROCESS OF TEMPORARY INSULATION OF INTERVAL OF ACTIVE POOL Russian patent published in 2002 - IPC

FIELD: oil and gas production. SUBSTANCE: process is related to temporary insulation of intervals of active pools, to killing of wells with abnormally low formation pressure for repair of wells, for isolation of lost circulation zones while wells are drilled. Technical result of invention consists in creation of temporary insulation with preservation of collector properties in critical area of formation during well servicing and general overhaul of wells for time period required for improvement of technological parameters of insulation material and reduced cost for realization of process. Process of temporary insulation of interval of active pool includes formation of viscoelastic packer by injection of polymer solution and cross-linking solution into critical area of formation with its subsequent destruction and well completion. Polyacrylamide is employed as polymer material, it is injected into formation simultaneously with cross-linking solution and stabilizer with following proportion of components, mas.%: polyacrylamide, 0.1-5.0; cross-linking solution, 0.05- 10.0; stabilizer, 0.1-5.0; water, the balance. Packer is destroyed by pumping aqueous solution of peroxide compound into critical area of formation. Soluble trivalent salts of chromium, for instance, Cr₂(SO₄)₃, Cr(C₂H₃0₂)₃, CrCl₃ can be used in the capacity of cross- linking solution, ammonium chloride can be employed as stabilizer and Na₂CO₃•H₂O₃- is peroxide of sodium carbonate, (NH₄)₂O₂S₈ is ammonium persulfate, H₂O₂ is hydrogen peroxide, (NH₄)₂CO₃•H₂O₃ is carbamide monoperoxide can find use as aqueous solution of peroxide compound. EFFECT: improved technological parameters of insulation material, reduced cost of realization of process. 3 tbl