RU2273730C1 - Water production method - Google Patents

Abstract

FIELD: water production from boreholes.

SUBSTANCE: method involves drilling production and injection borehole systems; penetrating borehole by perforation thereof; applying vibroacoustic pressure oscillations to formation, wherein the pressure oscillations are excited by acoustic borehole tools lowered in boreholes; producing water from boreholes. Injection borehole pipes are not perforated and are filled with working liquid. Acoustic oscillations are initially applied to production boreholes so that pressure in production boreholes preliminarily filled with fracturing liquid should be at least 2 times greater than formation breakdown pressure. Acoustic borehole device is located within perforation area. After crack opening water is lifted from production boreholes. During water lifting acoustic pressure oscillations are applied to formation through injection boreholes.

EFFECT: provision of water production in dry territories, increased economy and efficiency.

Description

The invention relates to the mining industry and can be used to intensify groundwater inflows from flooded areas saturated with water from porous deep underground formations and its production from boreholes.

In the mining industry, to intensify the influx of liquid minerals, the hydraulic fracturing method is widely used to create cracks in the near-wellbore zone of the formation (patent RU N2183739, IPC E 21 V 43/26, publ. 2002.06.20), which consists in using a powder PGD pressure generator placed into the perforation region of the casing filled with a fracturing fluid. After the powder charge is blown up, a high-pressure hydrodynamic pulse forms a system of cracks in the formation that are wedged by a proppant in the form of a calibrated proplant, and the cracks do not have the ability to close together, thereby increasing the productivity of the formation.

Such a technology requires a large expenditure of energy, a significant consumption of powder charges and chemicals.

The known method (patent RU No. 2203412, E 21 B 43/26, publ. 2003.04.27) create a water hammer using a pump plunger that pumps pressure in the tubing and its discharge when the plunger exits to its highest position. Pressure pulses propagate in a closed well completely filled with liquid, and the productive underlying interval is isolated by a cementing bridge. Impulses of pressure greater than the rock fracture pressure lead to the formation and propagation of cracks that are wedged by debris.

The disadvantage of this method is the high energy costs, the occurrence of large shock loads, the need for special injection materials for wedging cracks. In addition, such methods cannot be used to extract water from boreholes in arid or desert regions of the globe.

Known as a prototype is a method of processing a bottomhole formation zone, as well as water wells (patent RU 2191896, ЕВВ 43/25, publ. 2002.10.27). The method includes vibrating the bottom hole of the formation using a hydrodynamic oscillation generator, reducing the bottom hole pressure below the formation with simultaneous vibrating and increasing the pressure in the absence of pressure, changing the pressure cyclically, and in the pressure increasing cycles, hydrodynamic testing of the bottom hole of the well, and in pressure reduction cycles, the treatment mode is adjusted and judged on the advisability of terminating the processing weave.

The disadvantages of this method are similar to the disadvantages of the above analogues and are in high energy and other costs.

The objective of the proposed method is to eliminate the above disadvantages, ensuring the collection and production of water in arid areas, increasing the efficiency and effectiveness of the method.

The task with the achievement of the specified technical result is achieved due to the fact that in the method of water production, including drilling a system of production and injection wells, opening production wells by perforation, microwave exposure to the formation by acoustic pressure fluctuations excited by acoustic borehole devices immersed in the wells, and continuous the rise of water from production wells, while the pipes of injection wells are not opened by perforation and fill them with a working fluid, but acoustic pressure fluctuations are carried out first in production wells, while creating a pressure exceeding the formation fracture pressure by at least 2 times, pre-filling it with a fracture fluid, and the acoustic downhole device is placed in the perforation zone, and after opening the cracks, water rise from the production wells begin , during which the impact on the reservoir by acoustic pressure fluctuations is carried out through injection wells.

To increase the volumes and velocities of water movement in porous saturated massifs, the possibility of obtaining dilatancy (volume change due to plastic, irreversible deformation of the geomaterial, the generation of micro wells and microcracks) of the skeleton of the rock matrix is used. The downhole acoustic device (patent RU No. 2191258) works in the zone of plastic deformation, creating a pressure that is 2 times or more the fracture pressure, which is determined by the geological structure and, for example, for fields in Western Siberia is 26-28 MPa. An essential sign to achieve this goal is the need to create conditions for hydraulic fracturing in each commissioned production well, because this creates conditions for maintaining in a water-containing formation the conditions of dilatancy of the skeleton of the rock matrix and maintaining cracks in the open state. Acoustic impact at a frequency of more than 2 kHz leads to a high deformation rate, which in turn increases the value of the dynamic impact on the rock and is significantly higher than the static strength, which creates certain opportunities to achieve plasticity in the material of the skeleton of the rock matrix.

The indicated values of the increase in effective pressures are associated with the creation and maintenance of significant dilatancy of the skeleton of the rock matrix and the change in the volume of the rock both towards decreasing and increasing (loosening), which is the result of a change in the elasticity of the rock skeleton to plastic deformation values.

The higher the pressure created by acoustic radiation, the more cracks form during hydraulic fracturing. The presence and number of vertical and horizontal cracks, first of all, depends on the depth of the water-saturated formation, as well as on the presence and magnitude of the vertical and horizontal lithostatic pressures of the field. This means that all critical states of the porous matrix are determined by effective stresses. Porosity depends on volumetric deformations and on feather pressure. When the pore volume reaches a critical level, an important change occurs: the compaction of the geomaterial is replaced by its loosening, which can only be explained by the dilatancy process - a change in the volume of the skeleton of the rock matrix, which leads to the formation of filtering flows of the saturating liquid.

The method is as follows.

Production wells are perforated, filled with a fracturing fluid, for example, water, acoustic downhole devices are lowered into them, for example, described in patents RU No. 2140519, RU No. 2191258, and hydraulic fracturing is performed, creating an acoustic pressure of 56 MPa, exceeding the rock fracture pressure of 2 or more than once. The implementation of the hydraulic fracturing process is judged by the drop in the water level in the producing well, then the acoustic downhole devices are removed from the producing wells and lowered into the injection wells filled with the working fluid, applying acoustic pressure to the formation by creating excess pressure, and water is raised from the producing wells using pumps. Any available process water is used as the working fluid and the fracturing fluid.

Thus, the proposed method of water production is a new technology for collecting and extracting water to the surface in the absence of industrial water in vast spaces and territories. Efficiency and effectiveness of the proposed method is obvious.

Claims (1)

A method of producing water from boreholes, including drilling a system of producing and injection wells, opening the production wells by perforation, exposing the formation to acoustic pressure fluctuations excited by acoustic borehole devices submerged into the wells, and continuously raising water from production wells in which the injection well pipes are not open with perforation and fill them with a working fluid, while the impact of acoustic pressure fluctuations is carried out first in production wells, creating At the same time, the pressure exceeding the fracture pressure by at least 2 times, the producing wells are pre-filled with the fracturing fluid and the acoustic borehole devices are placed in the perforation zone, and after the formation of cracks in the formation, water begins to rise from the producing wells, during which the formation is exposed acoustic pressure fluctuations are carried out through injection wells.