Patent RU-2686768-C1 (RU)
Inventor: AMERKHANOV MARAT INKILAPOVICH
IPC: E21B49/00
Filed: 2018-08-01
Granted: 2019-04-30
Abstract: FIELD: oil and gas industry. 
     SUBSTANCE: group of inventions relates to oil industry. Method for development of super-viscous oil and / or bitumen deposit in compacted and clogged collectors involves use of a pair of horizontal injection and production wells, horizontal sections of which are arranged parallel to each other in vertical plane of treated formation, lowering of tubing string or coiled tubing of a coiled tubing combined installation, which allow simultaneous pumping of heat carrier and product extraction, pumping of heat carrier, heating of treated formation with creation of steam chamber, extraction of products through production well and control of process parameters of formation. Prior to lowering of tubing string or coiled tubing intake capacity of horizontal injection well and coefficients of clayiness and carbonate in bed of treated formation are determined. Range is selected with injectivity from 0.1 to 10 m 3 /day per 100 m of horizontal well barrel and clay factor from 0.05 to 0.95 unit fraction. Length and volume of the selected interval are determined. At length of allocated interval, equal to length of horizontal part of injection well, tubing string or coiled tubing is lowered above 3–5 m from bottom of horizontal injection well, acid composition is pumped through the tubing string or coiled tubing into the horizontal injection well. If the carbonate coefficient is from 0 to 0.049 unit fraction, acid composition contains, wt. fraction: 24 % inhibited hydrochloric acid 0.33–0.50; 70 % hydrofluoric acid 0.04–0.07; water – balance. At value of carbonate coefficient from 0.05 to 0.95 unit fraction, acid composition contains, wt. fraction: 24 % inhibited hydrochloric acid 0.33–0.50; water – balance. Volume of acid composition is determined depending on volume of allocated interval. Acid composition is pressurized with 5 % by weight aqueous solution of potassium chloride in volume of tubing string or coiled tubing. Column of process tubing string or coiled tubing is lifted to vertical part of well, horizontal injection well is closed for reaction till 4–5 h. Tubing string or coiled tubing is lowered above 3–5 m from the bottomhole and horizontal injection well is washed with aerated liquid in volume of not less than pumped acid composition to neutral pH value of the carried fluid pH. Then heat carrier is pumped and product is withdrawn. If the length of the allocated interval is less than the length of the horizontal part of the injection well, the tubing string or coiled tubing is installed in the middle of the selected interval; the above operations are performed starting from pumping of the acid composition before its injection. Then, the tubing string or coiled tubing is moved to the middle of the next selected interval and the above operations are repeated. Treatment is started with the selected interval closest to the working face. 
     EFFECT: increased coverage of the treated formation by thermal action, reduced time for heating of the treated formation, reduced power consumption for implementation of the method, increased coefficient of oil recovery. 
     2 cl, 4 dwg, 1 tbl, 2 ex