METHOD FOR CHEMICALLY FIXING PROPPANT IN HYDRAULIC FRACTURING OF GAS WELLS Russian patent published in 2023 - IPC E21B43/267 E21B43/22 

FIELD: oil and gas field.

SUBSTANCE: method for chemically propping proppant in a hydraulic fracture of a hydraulic fracturing formation of gas wells includes hydraulic fracturing in the well using a polymer gel for hydraulic fracturing, fixing the hydraulic fracture with a proppant, and treating the proppant. Before treatment, the proppant is pumped into the hydraulic fracture through the tubing with a breaking composition Polypron, including a non-concentrated solution of acid HCI or HCOOH, an enzyme or an oxidizing agent selected from the group: ammonium or potassium persulfate, magnesium peroxide, sodium percarbonate, to destroy the polymer hydraulic fracturing gel. A flushing composition PolyRIR-NF-AS (NFAS) is pumped into the hydraulic fracture, including a mixture of orthoxylene and isopropyl alcohol, the well is closed for reaction, the injection is carried out with an inert gas (nitrogen) followed by nitrogen purge until the gas injection pressure stabilizes at the level of reservoir pressure. The adhesive composition PolyRIR-NF-A, including a solution of aminosilane in orthoxylene, is pumped into the hydraulic fracture through the tubing, in the volume of the free pore space of the hydraulic fracture packing, nitrogen is squeezed, followed by nitrogen purging until the gas injection pressure stabilizes at the level of reservoir pressure. The proppant treatment is carried out in two stages. At the first stage, flexible tubing is lowered – coiled tubing equipped with a spray nozzle to the depth of the beginning of treatment - to the lower boundary of the perforation interval or the level of the lower boundary of the hydraulic fracture, through the coiled tubing, the fastening composition Polyskrep-reagent-1 is fed into the spray nozzle, including a mixture of a solution of organosilicon resins – polymethyl-, polymethylphenyl-, polyethylphenyl- and polyphenylsiloxane resins modified with polyesters in a solvent orthoxylene with a hardener aminosilane, and simultaneously in the tubing, in the annulus of the tubing and coiled tubing, nitrogen is pumped. In the process of injection by means of coiled tubing, the nozzle is moved from bottom to top and from top to bottom within the treated interval to form a gas-liquid mixture in the bottomhole zone purged with nitrogen. At the second stage, the reinforcing composition Poliskrep-reagent-2, which includes a mixture of epoxy resin with aromatic polyamines diluted with orthoxylene is fed through the coiled tubing into the spray nozzle, and nitrogen is pumped simultaneously into the tubing, into the annulus of the tubing and coiled tubing. In the process of injection by means of coiled tubing, the nozzle is moved from bottom to top and from top to bottom within the treated interval to form a gas-liquid mixture in the bottomhole zone, it is purged with nitrogen, the coiled tubing is lifted and dismantled, and well development is started.

EFFECT: preventing proppant runaway from the fracture, increasing the efficiency of gas wells in a wide range of process conditions, reducing water flow along the hydraulic fracturing fracture, increasing the overhaul period and increasing the operational reliability of gas wells with hydraulic fracturing.

1 cl, 1 tbl