DEVELOPMENT METHOD OF ULTRAVISCOUS OIL DEPOSIT Russian patent published in 2014 - IPC E21B43/24 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: development method of ultraviscous oil deposit includes construction of double-mouth upper injector and lower producer with horizontal sections, which are equipped with strainers having stacked openings. The strainer of the injector horizontal section is divided into two heating areas. Inside the strainer, opposite each heating area, liners with holes are installed, which are run in at ends of pipe strings from mouths of the injector. The liners are fixed rigidly to the respective pipe strings with possibility of hermetic closing or opening of the openings in the injector horizontal section. At the surface inner space of the pipe strings inside the injector are bundled by a pipeline with valves, while tubing-casing annulus of the injector is bundled by suction and discharges pipelines equipped with valves and a steam-generating plant. The pumping unit is bundled by hydraulic lines to tubing-casing annulus of the injector. At closed openings of the strainer at the injector horizontal unit heating of the cross-borehole stratum area is made, viscosity of ultraviscous oil is reduced in the stratum by closed circulation of heat carrier through tubing-casing annulus and inner space of the upper and lower double-mouth wells by the steam-generating plant without injection of the heat carrier to the stratum and heated ultraviscous oil is extracted from the producer. In process of closed circulation of the heat carrier through the injector, when temperature in the extraction area of the producer rises up to the value corresponding to viscosity of ultraviscous oil in the stratum sufficient for its solving by a hydrocarbon solvent the steam-generating plant is switched off and circulation of the heat carrier is stopped. Openings in the strainer of the injector horizontal section are opened by means of their matching to the holes in the liners. Hydrocarbon solvent is pumped by the pumping unit through tubing-casing annulus and strainer to the stratum thus forming a chamber with the solvent in the stratum where heated ultraviscous oil is liquefied. At that heated and liquefied ultraviscous oil is being extracted from the producer. As heated and liquefied ultraviscous oil is extracted, in result of stoppage of steam circulation temperature decreases and viscosity of oil increases in the extraction area up to the value corresponding to viscosity of ultraviscous oil in the stratum insufficient for its solving by hydrocarbon solvent. Thereafter the pumping unit is switched off and openings are closed in the upper double-mount injector by means of their disconnection with liners holes. The steam-generating plant is switched on and circulation of the heat carrier is resumed in the upper double-mouth injector. Further the process is repeated.

EFFECT: excluding water flooding of the stratum and water cut of the extracted oil, potential use of the method at bitumen deposits with thickness of layers up to 5-7 m, even development of the deposit, increasing oil recovery factor.

5 dwg