METHOD FOR DEVELOPING SUPER-VISCOUS OIL DEPOSITS AT A LATE STAGE Russian patent published in 2023 - IPC E21B43/24 E21B7/04 E21B47/09 E21B49/08 

FIELD: oil production industry.

SUBSTANCE: method for developing a highly viscous oil deposit involves constructing the pairs of horizontal wells - a production well and an injection well located above it, equipped with liner filters in the horizontal parts of the wells, heating the deposit by pumping steam as a heat transfer agent into both wells of each pair with heating of the productive formation and creating a steam chamber, subsequent pumping of steam through injection wells and selection of products due to steam-gravity drainage through production wells. After the extraction of the design recoverable reserves of super-viscous oil in one of the pairs of wells, the injection of steam into the injection well and the withdrawal of liquid from the production well of the specified pair are stopped. In the specified production well, the current interval of propagation of the steam chamber is determined, flaw detection and microcavernometry are carried out, the condition of the production string is assessed, and the location of the coupling pipe connections in the specified production well is determined. A kickoff interval is selected for a new horizontal wellbore 2-3 m below the current interval of steam chamber propagation and at a distance of at least 2 m below the coupling joint of the production string pipes. A whipstock is lowered into the cooled specified production well with the bevel directed towards the placement of a new horizontal wellbore of the specified production well. A window is cut out in the casing of the specified production well, through which a new horizontal trunk is drilled, which is placed parallel and at a distance of 30-70 m from the main horizontal trunk of the specified production well. A new horizontal trunk of the specified production well is equipped with a liner filter. Next, steam is pumped into both horizontal shafts of the specified production well at an intensity of 90 tons/day for one month. After this, steam injection into the horizontal shafts of the specified production well is stopped and left for thermocapillary impregnation for 14 days. Next, an electric centrifugal pump is lowered into the new horizontal wellbore of the specified production well and it starts to extract liquid. When the temperature of the produced fluid drops to 30°C or less, the selection of liquid from the new horizontal wellbore of the specified production well is stopped and the injection of steam at an intensity of 90 tons/day is resumed for one month into both shafts of the specified production well and subsequent thermocapillary impregnation for 14 days. The measures are repeated until a hydrodynamic connection is obtained between the injection well of the specified pair and the new horizontal wellbore of the production well of the specified pair - until the temperature of the withdrawn fluid is restored to 30°C and above and establishing such a temperature in a constant mode and again launching a new horizontal trunk of the specified production well for liquid extraction.

EFFECT: increase in the efficiency of liquid selection, reduction in the likelihood of gas and vapour manifestations and the risk of complications and accidents.

1 cl, 3 ex