METHOD FOR DEVELOPMENT OF STICKY OIL AND BITUMEN ACCUMULATION Russian patent published in 2014 - IPC E21B43/24 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: method for development of sticky oil or bitumen accumulation includes drilling and infrastructure development of at least one pair of horizontal wells for steam gravity drainage with borehole location of the injection well parallel in vertical plane over the producing well borehole, steam injection to the injection well and product recovery from the producing well. Configuration of wells corresponds to the formation shape: ascending at the formation start, horizontal in the central part and descending at the formation end. Ascending and descending angles of the producing well is equal to the formation pitch angle and ascending and descending angles of the injection well is 1-2.2 times more than the formation pitch angle. Minimum distance from perforated holes of the producing well to oil-water contact is taken equal to 2 m, minimum distance between boreholes of the producing and horizontal wells is equal to 3 m, maximum distance between horizontal sections of the boreholes of the producing and injection wells is equal to 10 m. Distribution of shot density and ascending and descending sections shall be determined as per the formula: n_x=n₀+L_x/A, where n_x is a number of perforation holes at ascending and descending sections at distance X from the beginning of the perforated borehole; n₀ - minimum shot density at the section with minimum distance between the producing and injection wells in the perforated parts of boreholes; L_x - length of ascending and descending sections of the perforated borehole at distance X from its beginning; A=30-60 m. When drilling and infrastructure development is completed the bottom-hole zone is heated up within 1-6 months by steam injection into producing and injection wells under pressure of 1-2 MPa or by downhole heaters, thereafter injection well is started up with permanent steam intake of 75-95 m³/day while in the producing well recovery is started with bottom-hole pressure of 0.25-0.35 MPa.

EFFECT: increasing oil recovery factor for the productive stratum and reducing water flowing rate of the producing wells at development of sticky oil or bitumen accumulation of massive or structural lithological types.

1 ex, 2 dwg