METHOD FOR DEVELOPING LAYER OF ULTRA-VISCOUS OIL BY UNIFORM VAPOR-GRAVITY ACTION Russian patent published in 2021 - IPC E21B43/24 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry and can be used in the development of layers of ultra-viscous oil by the method for steam-gravity action. A method for developing an ultra-viscous oil reservoir by uniform steam-gravity action is proposed, including drilling and arrangement of a pair of parallel horizontal wells, where the horizontal shaft of the injection well is placed above the horizontal shaft of the producing well, descent of casing strings into the horizontal wells, cementing of the annulus, perforation, steam injection into the injection well and uniform heating of the steam chamber due to controlled steam injection and changes in the heating zones, taking into account the thermograms obtained during steam injection, selection of products from the production well. In this case, the annular space along the entire length of the horizontal injection well bore through the perforation holes in the casing string is discretely isolated by local placement of heat-resistant plugging material in it, thereby dividing the horizontal injection well bore into intervals of 20-100 m. A flexible steam pipe is lowered into the injection well, the shoe of which is equipped with packers to prevent steam from escaping into the well space behind the packers and beyond the intervals of the trunk, a perforated pipe is placed between the packers to pump steam into the formation. Moreover, the perforated branch pipe is made with a length not exceeding the distance between the intervals of the shaft. The injection of steam into the injection well and the uniformity of the heating of the steam chamber are regulated by moving in the casing along the horizontal trunk of the shoe of the specified steam pipe with a perforated branch pipe at a speed of 0.1-1 m/s and stopping between intervals for the heating time of 6-48 hours.

EFFECT: increased coverage and coefficient of oil recovery of the reservoir due to the uniform heating of the reservoir along a pair of wells through the use of a movable steam line.

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