METHOD FOR EXTRACTING EXTRA-VISCOUS OIL AND/OR BITUMEN FROM DEPOSITS WITH SMALL FORMATION THICKNESSES (OPTIONS) Russian patent published in 2022 - IPC E21B43/24 E21B43/22 E21B43/27 E21B33/138 C09K8/592 C09K8/74 C09K8/42 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry. Methods for extracting extra-viscous oil and/or bitumen from a reservoir with small formation thicknesses include drilling a well in a productive formation, placing a tubing string in the well, pumping solvent and steam into the well, holding to distribute heat in the formation, withdrawing liquid with a pump. In the claimed methods, the injectivity of the steam-cyclic well and the water-producing interval are preliminarily determined, steam is injected until a steam chamber is formed. With an injectivity from 50 t/day to 300 t/day and the absence of a water-producing interval, the solvent and steam are jointly injected, the solvent is injected in a volume from 10% to 30% of the daily steam injection, then a technological exposure is carried out for at least 21 days, then the liquid is withdrawn by the pump. With an injectivity from 50 t/day to 300 t/day and the presence of at least one water-producing interval, a heat-resistant water-insulating composition is pumped into the steam-cyclic well in the following ratio of components, wt.%: polyacrylamide 0.3-0.7; guar 0.3-0.7; chromium acetate 0.05-0.06; zinc oxide or magnesium oxide 0.05-0.06; formaldehyde 0.2-0.3; water - the rest, in the amount of 0.036 m³ of the water-insulating composition per 1 m of the length of the open water-producing interval in the wellbore, the heat-resistant water-insulating composition is forced into the formation with the process liquid, and the process is held for gelation for at least 24 hours, further, the solvent and steam are jointly injected, the solvent is injected in a volume of 10% to 30% of the daily steam injection, then a technological exposure is carried out for at least 21 days, then the liquid is withdrawn by a pump. With an injectivity of less than 50 t/day and the absence of a water-producing interval, a 12% aqueous solution of inhibited hydrochloric acid is pumped into a steam-cyclic well in a volume of 0.05-0.075 m³ per 1 m of the length of the open wellbore, a 12% aqueous solution of inhibited hydrochloric acid is forced through into the reservoir with water, a technological soak is performed for a response for a duration of 4 hours, the steam cycle well is washed with aerated liquid or swabbed to a neutral pH value of the liquid being carried out, then jointly inject the solvent and steam, the solvent is injected in a volume of 10% to 30% of the daily steam injection, then, a technological holding is carried out for a duration of at least 21 days, then the liquid is withdrawn by a pump. As a solvent, toluene or an industrial solvent, or a mixture thereof in a volume ratio (1-4):1, is used.

EFFECT: increasing the efficiency of extracting extra-viscous oil and/or bitumen from a reservoir with small reservoir thicknesses by increasing the coverage of steam exposure to the reservoir and increasing the steam chamber.

3 cl, 1 tbl, 3 ex