RU2005139750A - METHOD FOR INSULATING A FLUID-CONTAINING LAYER AND A DEVICE FOR ITS IMPLEMENTATION - Google Patents

Claims (2)

1. A method of isolating a fluid-containing formation, including the creation of a disk-shaped cavity in the rock and the subsequent filling of the disk-shaped cavity with cement slurry, characterized in that in the interval of the rocks of the tires lying over the formation in close proximity to it, create a technological window, the height of which is determined depending from the vertical axial load on the installed fluid-resistant screen, the adhesion of the cement stone with the rock and the extended diameter of the well according to the formula

where K is the safety factor; H - the height of the installed screen;

where P ₁ , P ₂ - pressure acting on the sole and roof of the screen, kg / cm ² ; F _cp - averaged cross-sectional area of the well, cm ² F _cp = π Rcp ² , where R _cp is the average radius of the well, cm, axial shear load is determined from the expression

where δ is the amount of adhesion of the screen material to the rock, kg / cm ² ; D _cp is the average diameter of the cross section of the well, cm, the height of the installed screen is calculated by the formula (1), while completely destroying the body of the casing string, the diameter of the wellbore in this interval is less than the diameter of the formation zone during drilling of horizontal and vertical macro- and microcracks, erode the rock and create at least 2-3 caverns, the diameter of which is 1.5-5.0 times larger than the zone of formation of macro- and microcracks through 1.0-5.0 m in height of the technological window, fill the wellbore and disk-shaped caverns with a working agent in the form of lightweight about saline or aqueous solution, then the entire volume of the wellbore and disk-shaped caverns under the influence of gravity are filled with cement slurry, while the cement slurry has a density greater than water and lightweight solution, lower the pressure column and with a low flow rate of 0.5-3.0 l / s fill the open wellbore and disk-shaped caverns with cement slurry with overlapping the shoe of the upper part of the casing string by less than 10-20 m and increase the pressure without exceeding 0.8 hydraulic fracturing. 2. The device for implementing the method according to claim 1, comprising a housing, guiding jet nozzles and a valve ball, characterized in that the housing is rigidly fixed to the hollow shaft of the rotor of the downhole motor, which is attached to the pressure pipe string, the guiding jet nozzles are located radially and evenly throughout the circumference of the housing in the upper, middle and lower horizontal planes of its cross section of 3-6 nozzles for each plane; the device is equipped with bypass channels connecting the internal cavity of the device with the guiding jet nozzles, while the jet nozzles are combined into two groups of alternating action, one of the groups is connected to one of the bypass channels, the second to the other bypass channel, nozzles located in the middle horizontal plane, oriented in a strictly horizontal plane, nozzles located in the upper and lower horizontal planes, spaced from each other by 0.15-0.5 m, are installed at an angle of 7-30 ° to the horizontal oskosti, the device is also provided with a slide valve mounted in its upper part an additional ball valve.