METHOD OF CONSTRUCTION OF HORIZONTAL WELL Russian patent published in 2015 - IPC E21B7/04 E21B43/25 E21B33/14 

FIELD: mining.

SUBSTANCE: in the process of construction of horizontal well, the deviated hole is drilled through the rocks, descending of the upper casing pipe, cementing the borehole annulus behind the upper casing pipe, drilling the horizontal shaft from the upper casing pipe to the lower oil reservoir, descending of the lower casing pipe with a partial placement of the latter in the lower part of the upper casing pipe, cementing the borehole annulus behind the lower casing pipe, perforation of the horizontal shaft, descending to the upper casing pipe of flow string with a packer with mounting of the packer and the shoe of the flow string in the upper casing pipe over the lower casing pipe, and performing the hydraulic fracturing in the horizontal shaft. As a part of the upper casing pipe in the interval of the upper producing layer the well casing of increased thickness are used, where the packer is placed. During the hydraulic fracturing of the lower oil reservoir the pressure is created over the packer, which is allowed on the upper casing pipe. Then the simultaneous release of pressure above and below the packer is carried out, perforating of the upper casing pipe is carried out in the interval of the upper oil reservoir, and development of the well. The height of the cement sheath between the packer top and the lower oil reservoir is determined from the ratio: $$L\ge \frac{P_{HFL}-P_{OP}}{2},$$ where P_HFL is pressure of hydraulic fracturing of the layer, MPa; P_OP is pressure in the over-packer space in the process of hydraulic fracturing of the layer, MPa; L is the height of the cement sheath between the packer top and the lower oil reservoir, m; 2 is the reliability coefficient of the cement sheath, MPa/m.

EFFECT: elimination of flows in the hydraulic fracturing crack, crushing the production casing above the place of the packer mounting, and reduction of water cut of the excavated product.

1 dwg, 1 ex