The results of pilot oriented hydraulic re-fracturing of two wells in the oil fields in the South of Perm region are presented. Generally the idea of oriented hydraulic re-fracturing is to create a system of perforations or lateral radial boreholes in a reservoir oriented perpendicular to the initial fracture and in a vertical plane. The distance between boreholes is determined based on geomechanical calculations. The technology of calculations comes down to the determination of the distance between small lateral boreholes depending on the existing geomechanical conditions and the in-situ stress which will allow the interaction of the boreholes and the subsequent creation of a fracture between them. Also the distance between two fracture systems created using lateral boreholes is determined to allow the propagation of the main fracture through the whole section. In connection with this the thorough study of reservoir geomechanical properties, in-situ stress near the considered wells and the initial hydraulic fracturing results was carried out before performing the oriented re-fracturing treatment. The stress field around the well should have a relatively small anisotropy (ratio more than 0.8 and meet the requirements for the vertical fracture formation). The azimuth of the initial fracture must be clearly known. Additional (highly desirable) condition is that the minimum initial fracture opening width should be no less than 10 mm near the wellbore.
The results of full-wave acoustic logging confirm that during some stages the fracture propagated in the predetermined direction.
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