METHOD FOR PRODUCING HIGH-VISCOSITY OIL WITH IN-WELL THERMAL ACTIVATION OF BINARY SOLUTION Russian patent published in 2024 - IPC E21B43/24 C09K8/592 

FIELD: oil and gas industry.

SUBSTANCE: invention is applicable for horizontal or inclined multifunctional wells that combine the functions of production and injection. In the method of producing high-viscosity oil with in-well thermal activation of a binary solution, a well is first equipped, then a binary solution is injected containing, wt.%: ammonium nitrate - 27.8; sodium nitrite - 32.2; the balance is water, which is supplied through the annular gap, bypass pipe and lower column to the end section of the casing pipe. Next, the binary solution through the first opened zone or the second opened zone enters the productive formation and is then pressed with light oil with a density of no more than 0.92 g/cm³. Next, downhole thermal activation of the exothermal chemical reaction of the injected binary solution is started using the method of superheated steam injection, for which superheated steam at a temperature of 310°C is pumped into the well through a perforated injection pipe. After the reaction starts, which is determined by the increase in pressure and temperature on the installed control devices, steam supply is stopped. Next, a chain chemical reaction begins with the release of heat sufficient to form a thermal front throughout the entire treated zone of the formation, an increase in pressure and temperature appears, which are recorded by sensors. Heat is propagated in the porous medium by reaction products, and the thermal front heats up the highly viscous oil in the reservoir. The heated oil-water emulsion with reaction products flows through the first opened zone into the annulus between the lower column and the initial section of the casing, then it enters through a built-in adjustable valve to receive a submersible pump, then it is pumped to the surface through an additional pipe. When the flow rate decreases, pumping is stopped and the binary solution is reinjected into the productive zone of the formation through the lower column to increase oil fluidity, then pumping is carried out and the cycles are repeated.

EFFECT: increased oil recovery, ability to select the time from the start of binary solution injection to the start initiation of an exothermal chain reaction, the ability to delay the onset of chemical exposure to the bottomhole zone without the risk of premature start of the chemical reaction.

1 cl, 3 dwg, 1 tbl, 1 ex