PROCEDURE FOR DIRECTIONAL HYDRAULIC BREAKDOWN OF FORMATION IN TWO HORIZONTAL BORES OF WELL Russian patent published in 2010 - IPC E21B43/26 

FIELD: oil and gas production.

SUBSTANCE: invention can be implemented at development of oil deposits, particularly at deposits with producers of low collecting filtration and capacitance properties by means of hydraulic breakdown of formation - HBF. The procedure consists in drilling two horizontal bores from a vertical borehole, in their perforation, and in pumping breakdown fluid and a sand carrier into both horizontal bores. According to the invention horizontal bores are arranged parallel in one vertical plane or horizontal bores can be unparallel with an angle between them. Projection of an upper horizontal bore of the well onto horizontal plane passes through axis of a lower horizontal bore of the well perpendicular to axis of a vertical bore of the well. Further, a casing string is lowered into each horizontal bore; annular space between the casing string and rock is cemented in both horizontal bores of the well. The horizontal bores of the well are perforated by means of a slit perforator per one round-trip operation in each horizontal bore of the well directed azimuthally in a direction from one horizontal bore to another in one vertical plane. This plane passes parallel to axis of the vertical well and perpendicular to axis of the lower horizontal bore of the well. Fluid of hydraulic breakdown and sand carrier are thereafter pumped into each horizontal bore. Opening-out working fluid on hydrocarbon base is used for hydraulic-mechanical slit perforation.

EFFECT: raised efficiency of directional HBF and minimised amount of round-trip operations at secondary formation opening-out before HBF.

3 cl, 3 dwg