METHOD FOR LIQUIDATION OF HYDRATE AND GAS HYDRATE PLUGS IN OIL AND GAS WELLS Russian patent published in 2021 - IPC E21B37/06 C09K8/52 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, in particular to methods of destruction of hydrate, gas hydrate, hydrate hydrocarbon and ice deposits in the form of solid plugs. The method includes dissolving a divalent metal halide, a polyhydric alcohol and a betaine selected from the group consisting of erucylamidopropyl betaine or oleylamidopropyl betaine in water, supplying the solution to the annular or tubular space and destruction of gas hydrate deposits. The iodide of zinc, nickel, tin, manganese, magnesium, calcium, barium, iron; the chloride of barium, calcium, manganese, nickel, tin, copper, iron; the bromide of barium, calcium, magnesium, manganese, nickel, tin, copper, iron can be used as a bivalent metal halide in an amount of 20-75% by weight, the rest is water. The solution is stirred at a speed of 40-800 rpm for 20-60 minutes, while cooling to a temperature of 20-40°C. A polyhydric alcohol selected from the group consisting of methanediol or propylene glycol, or butanediol, or isobutylene glycol, or low molecular weight polyethylene glycol with a molecular weight of 200 to 1000 units or polyglycol of the brand "Glykoil-1" is added in the amount of 1.5-6% of the mass. Betaine is also added in an amount of 1.0% of the mass up to 6.0% of the mass. After that the solution is stirred at a speed of 20-600 rpm. Further, the composition of the micellar structure with a viscosity of 50-1200 Pa·s, a density of 1.1 kg / m³ to 2.4 kg / m³, a freezing point from minus 5 ° C to minus 45°C is fed into the annular or tubular space of an oil well, with a ratio of 1 m³ of composition per 4-8 m³ of gas hydrate plug, passing through layers of oil, saline formation water and process fluid in the well to the surface of the gas hydrate plug, destroying it within 2-15 hours, with constant pressure control.

EFFECT: speed increases and the time of destruction of hydrate and gas hydrate deposits decreases with a controlled process of destruction of a solid plug.

1 cl, 1 tbl,1 dwg