METHOD OF OPERATION OF HYDROCARBONS RESERVOIR Russian patent published in 2015 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: under the method at the initial stage subhorizontal wells are drilled with vertical, two inclined sections of the well bore at angles 30-40 degrees and 45-60 degrees, respectively, from vertical, and with horizontal section of the well bore. At that the vertical section is drilled till shoe of the conductor covering the permafrost. The first inclined section at angle 30-40 degrees is drilled to input to the productive formation, and is cased by the production string. The second inclined section at angle 45-60 degrees from vertical cased by the filter-liner is drilled through the productive formation to elevation by 20 m above the initial gas- or oil-water contact. The horizontal section with length 150-450 m is drilled through the productive formation parallel to the gas- or oil-water contact. In the horizontal bore the well filter with holes is installed. In the internal cavity of the production string the tubing string is installed to the shoe of the well filer. During operation initially gas or oil is extracted through holes of the well filter using the tubing string. With the formation pressure decreasing, and water cone of the formation water movement to the horizontal section of the well bore, and closing by it 50-80% of holes of the well filter the tubing string is lifted to the roof of the productive formation, and perforation through this string in gas or oil environment of the liner-filter is performed. Perforation is performed in interval from the productive formation roof to the head of the well filter considering location of the lower perforation holes by 10 m above the current gas- or oil-water contact. Then the horizontal section of the well bore is liquidated, for example, by means of pumping in of the cement slurry via the flexible pipe lowered in the internal cavity of thee tubing string, or by closing of the well bore by the bridge plug. Then operation of the hydrocarbons formation at the final stages is performed by gas or oil extraction through the perforation holes of the liner-filter via the tubing string.

EFFECT: increased duration of gas or oil production from the watered out wells, and increased oil and gas recovery factor of the formation with minimum expenses.

5 dwg, 3 ex