METHOD FOR ISOLATING WATER INFLOWS IN GAS WELLS WITH A SUB-HORIZONTAL WELLBORE END Russian patent published in 2023 - IPC E21B33/138 

FIELD: isolating water inflows in gas wells with a sub-horizontal wellbore end.

SUBSTANCE: method includes lowering pumping and compression pipes (PCP), equipped with a hydraulic installation assembly into the well to the bottom of the treated formation interval. Blind and filling bridge plugs are installed in the well. A lower in-situ insulating bulkhead is formed by pumping a gel-forming water-insulating composition into the inter-packer zone and forcing it into the formation with a displacement fluid. The PCP is removed from the well and the filling bridge plug is drilled out. The PCP is lowered, equipped with a hydraulic installation assembly, to the roof of the treated formation interval. Blind and filling bridge plugs are installed in the well and an upper in-situ insulating bridge is formed by pumping a gel-forming water-insulating composition into the inter-packer zone and forcing it into the formation with a displacement fluid. The depth of the formed in-situ insulating bridges is equal to at least 2-3 well radii. The PCP is removed from the well and the blind and filling bridge plugs are drilled. The PCP is lowered, equipped with a hydraulic installation assembly, to the roof of the treated formation interval. A filling bridge plug is installed in the well and a gel-forming water-insulating composition is pumped into the inter-packer zone in a volume equal to 0.5 of the pore volume of the treated formation interval, it is pressed through and left for a while. The PCP is lifted, the hydraulic installation assembly is removed from the filling bridge plug, a portion of the gel-forming water-insulating composition is pumped into the tubing, it is forced to the bottom hole with a displacement fluid until the gel-forming water-insulating composition reaches the hydraulic installation arrangement. The injection is stopped, the annular space is closed and the hydraulic installation assembly is installed in the filling bridge plug. Then, the gel-forming water-insulating composition is injected into the inter-packer zone. It is pressed into the formation with a displacement fluid and left for a while until complete settling down of the structure. The PCP is removed from the well and the remaining bridge plugs are drilled out.

EFFECT: increase of efficiency of isolation of water inflows with the maximum possible preservation of the porosity and permeability properties of the borehole zone of a production facility and an increase in the overhaul period of the well.

1 cl, 4 dwg