METHOD OF EXTRACTING HIGH-VISCOUS OIL AND NATURAL BITUMEN FROM THE RESERVOIR Russian patent published in 2018 - IPC E21B43/24 E21B49/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, and in particular to methods for the development of high-viscosity oil or natural bitumen deposits by horizontal wells. Method of extracting high-viscosity oil and natural bitumen from the reservoir includes drilling a well in the formation for cyclic injection of solvent and oil recovery using a pump, prior to the start of injection, preliminary studies and determination of the composition of the core oil are carried out, and on their basis, the composition of the plug and bursting composition is selected, horizontal wells are drilled in the foot zone of the productive formation, directional perforation of the horizontal section of the well along the upper generatrix of the wellbore, injection of the plug composition under pressure, exceeding the hydraulic fracturing pressure, into the well. In this case, the plug composition includes a non-ionic surfactant, the volume ratio of aliphatic, aromatic and surface-active components is (90–80):(≤10):(≤10). Then, a mixture of aliphatic components with an ionic surfactant in the ratio of (≥90):(≤10) is used as bursting composition to reduce the interfacial tension between the injected composition and the steam condensate to improve steam penetration, then steam is pumped to reduce the viscosity of the produced products.

EFFECT: technical result is the creation of a technologically advanced method for extracting high-viscosity oil and natural bitumen from the reservoir, which increases the range of known methods, allowing to select an effective composition using preliminary studies, quickly and accurately control the physicochemical properties of the extracted high-viscosity oil or natural bitumen due to the two-step injection of solvent compositions to prevent the processes of asphaltene-resinous components falling out in the productive formation, and due to the directed perforation of the horizontal wellbore – to achieve the most complete coverage of the productive formation using one well instead of two.

4 cl, 3 dwg