METHOD FOR INTENSIFYING BOREHOLE OPERATION BY DRILLING SIDE HOLES Russian patent published in 2021 - IPC E21B7/04 E21B43/16 E21B43/25 

FIELD: drilling.

SUBSTANCE: invention relates to the field of drilling side holes of petroleum and gas boreholes. The method for intensifying borehole operation by drilling side holes includes drilling the main horizontal and additional side holes, acidising the additional side holes. The main horizontal hole is drilled at a distance to the oil-water contact (OWC) of no less than 4 m. Before the additional side holes are drilled, a retrospective analysis of changes in the dynamics of formation pressures, water cut of the yield, oil production rates of a horizontal open borehole is conducted. A hydrodynamic model is constructed. The least mined area with a current oil saturation of at least 46% with current residual reserves of at least 10 thousand t. unevenly distributed over the area due to an uneven borehole grid is selected. A section of the main horizontal side hole with the greatest curvature in the horizontal plane is selected. The distance to the OWC in said section is determined. The first additional horizontal side hole is drilled at an angle of 3° relative to the main horizontal side hole in the direction of curvature. Retraction to least 30 m from the beginning of the first additional horizontal side hole towards the beginning of the main horizontal side hole is conducted. The section of the main horizontal side hole in this area with the greatest curvature in the horizontal plane and the distance to the OWC in this section are determined, and the second additional side hole is drilled at an angle of 3° relative to the main horizontal side hole in the direction of the curvature. The described operations for drilling additional side hole are repeated. The length of the additional side hole is selected depending on the distance to the OWC: at a distance to the OWC from 4 to 10 m, an additional side hole with a length of 28 m to 80 m is drilled, at a distance to the OWC from 10.1 to 12 m, an additional side hole with a length of 80.1 up to 96 m is drilled, at a distance to the OWC of 12.1 m and more, an additional shaft with a length of 96.1 m and more is drilled. Following the drilled additional side holes, the rock is subjected to water jet cutting with an acid composition with a specific consumption of the acid composition per running meter of the processing interval of at least 0.08 m³/m in the dynamic mode at a working pressure of no less than 20 MPa. The acid composition is then squeezed with a process fluid.

EFFECT: intensification of borehole operation is ensured by drilling side holes, petroleum recovery is increased, and additional development of the reserves of the section of the borehole is ensured.

1 cl, 1 dwg