METHOD OF INJECTION WELL OPERATION WITH SINGLE-LIFT MULTI-PACKER ASSEMBLY Russian patent published in 2018 - IPC E21B43/14 E21B33/122 E21B47/06 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: method includes running in the assembly to the well, setting packers and their leak testing, dual injection of working fluid to production formations. The assembly is mounted. Axial packer is used as the lower packer and thrust plate packers are used as the upper packers. If instruments are available in the assembly, the cable is connected to the instruments and fixed on the assembly outer surface. The assembly is run in and its hydraulic leak testing is performed. The plug is removed by means of wire-line technique. The assembly is run to the well to a required depth on the tubing string with diameter smaller than the operating string by 1.6 to 2.9 times. The tubing string is run by measuring the length and gaging the inner cross-section of the tubing string. If the cable is available, it is simultaneously fixed at outer surface and the cable is run in together with the tubing string. The packers are positioned, fitting of the assembly is made to the preset interval by adjustable tubes, chuck is mounted, hydraulic leak testing is performed for the tubing string. The packers are installed. The packers are pressurized, and pressure controllers or well gauges are installed with pipe unions of given diameters in well chambers. During the operation, revision, manipulation or replacement of pipe unions of pressure controllers to the other diameter of pipe unions or installation of plugs is carried on regular basis. The revision, manipulation or replacement of unions is performed when the change of fluid pumping through isolated objects or prevention of boiling, sticking, filling of flow controllers is required. When injectivity of injection well of formations is reduced or additional oil production from reacting production wells is reduced, acid treatment is carried out in required interval of formations without extraction of single-lift multi-packer assembly. For this, investigation of flow rate and/or thermometry is carried out by cable or wire-line technique in interval of flow controllers and/or well chambers and/or formations. According to investigation result, the object for acid treatment is selected. By means of cable or wire-line technique, flow controllers are extracted from all well chambers in front of intervals of formations, the plugs are installed instead of flow controllers into well chambers in the interval of objects or formations where acid treatment is not necessary. Well chambers are left open in the interval of objects or formations where it is necessary to increase the injectivity. A flexible pipe with packing or furnace with 38 mm diameter is run by coiled tubing, flushing to the shoe of multi-packer assembly and/or treatment with use of paraffin solvents in volume from 3 to 15 m³ with expectation of reaction and/or with circulation for 3 hours of tubing string is carried out. Injectivity of formation or object is determined by injecting 3-6 m³ of fluid. Acid treatment of formation or object is carried out at 0.5-3 m³ rate per 1 meter of formation or object width. If necessary, acid residues are washed out and/or injected. Injectivity of formation or object is determined by injecting 3-6 m³ of fluid. Previously installed plugs are removed by cable or wire-line technique, and unions of 1-9.5 mm in diameter are installed or not installed on all well chambers in the interval of formations or objects. The well is used for injection for a certain time. The well is investigated by flow rate and/or thermometry in the interval of flow controllers and/or well chambers and/or formations. In accordance with the obtained investigation results, the required well remains in operation. In case of mismatch of obtained investigation results, the replacement of flow controllers and/or unions in well chambers and investigation of the well is repeated until required result is obtained.

EFFECT: higher operation efficiency of wells with single-lift multi-packer assembly.

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