RU2340774C2 - Method of hydraulic borehole mining of minerals - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to mining and can be employed at development of deposits of minerals in form of an edge seam overlapped with mass of rocks of basic sediments by means of borehole hydraulic mining. The method of hydraulic borehole mining incorporates opening out a rock mass overlaying a producing horizon with a vertical borehole; then a successive boring of several producing inclined wells is performed out of this borehole in several directions along the pitch at a hanging wall, then up and down washing out of the horizon of deposits is carried out from producing wells, and as a hydraulic borehole device goes up, a case column is taken out; before termination of borehole washing out a required safety massif of rock is left at the upper portion of the borehole.

EFFECT: increased efficiency of hydraulic borehole mining of minerals and increased output owing to extension of development zone.

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Description

The invention relates to mining and can be used in the development of minerals in the form of steeply falling reservoir, overlapped by the thickness of the rocks in the form of sedimentary deposits by the method of downhole hydraulic production.

The well-known "Method of testing powerful underground formations" (USSR AS, No. 1318689, 06.23.87 BI No. 23), designed to extract samples from steep and inclined mineral formations. A powerful inclined formation is opened by two production wells - a formation inclined by the dip at the hanging side, to the lower test line and vertical, also to the lower test line, and they are faulted. A hydraulic monitor is placed in an inclined well, and a pulp-lifting column is placed in a vertical well.

The disadvantages of this method are:

- the need to drill two wells at great depths;

- unreliability of the process of well shutdown due to their curvature and small diameters.

Closest to the claimed technical solution is the "Method of downhole hydraulic mining and device for its implementation" (RU No. 2256796, publication date 2005.07.20).

The method includes opening a productive formation with a production deviated well, casing a well with a pipe string, installing a well projectile with concentrically arranged pipe columns, a hydraulic elevator and a hydraulic nozzle. Hydro-monitor erosion of the formation and lifting of the resulting hydraulic mixture of rocks with a hydraulic elevator to the surface are performed. The productive formation is opened by a production inclined well and cased by moving the external pipe string along the axis of the well and simultaneously rotating the internal pipe string, while the nozzle is introduced into the external pipe string, and when the productive layer is eroded, it is removed from the external pipe string downhole projectile.

The main disadvantages of this method are:

- the need for drilling inclined wells of a large volume of covering mineral deposits, which may have a complex structure and contain more than one aquifer;

- no measures are provided to prevent deformation of the earth's surface during drilling operations;

- the constant rotation of the inner column, which leads to its rapid wear.

A device is known for implementing this method (RU No. 2256796, publication date 2005.07.20), made in the form of a borehole projectile, including concentrically arranged pipe columns, the external of which is a casing of the well, and the internal one is equipped with a tip with a hydraulic elevator, a hydraulic nozzle and a sealing element and a head in the form of a two-pass swivel for supplying and dispensing pulp, while the sealing element is mounted on the tip above the nozzle and is made in the form of a cylindrical height stupid.

The disadvantages of this device are:

- the installation of a hydraulic nozzle with a gap inside the outer string of pipes when drilling wells leads to the formation of an annular jet, resulting in increased water consumption, requiring an additional source of water supply;

- the implementation of a downhole projectile with the possibility of constant rotation of the inner pipe string while drilling the well leads to its increased wear;

- lack of centering devices on the inner pipe string that are necessary in deviated wells, which leads to runout and accelerated wear of the inner pipe string.

The objective of the proposed technical solution is to create a method of downhole hydraulic mining of minerals for the development of steeply dipping deposits occurring among stable enclosing rocks, overlain by the thickness of sedimentary formations, which reduces material costs, allows to ensure the safety of drilling operations, and also to expand the development zone and thereby increase production minerals, as well as the creation of a device for implementing the above method.

The problem is solved due to the fact that a method of downhole hydraulic mining of minerals is proposed, which includes opening a productive formation by a production deviated well, casing a pipe string, installing a hydraulic production projectile and hydraulic elevator in the well, hydraulic monitor erosion of the formation and lifting the resulting hydraulic mixture of rocks with a hydraulic elevator to the surface and differs from the closest technical solution in that:

- in the thickness of the rocks covering the reservoir, construct a vertical well before opening, which speeds up the process of opening the reservoir and reduces material costs;

- from a vertical well, several production inclined wells are drilled sequentially in different directions by the dip of the formation at the hanging side, which allows to expand the development zone and thereby increase the volume of mining;

- from production deviated wells carry out erosion of the mineral layer from the bottom up, which allows you to create the necessary safety pillar from deformation of the earth's surface in the upper part of the deviated well;

- as the hydro-production shell rises, casing pipes are removed from the production deviated well, which also reduces material costs in mining.

The problem is solved by using a device for downhole hydraulic mining of minerals, including a hydraulic production shell with hydraulic monitors installed on the inner pipe string, and a hydraulic elevator for generating the resulting hydraulic mixture using an external pipe string. Moreover, according to the proposed device, the hydraulic monitors are connected through communication with two bushings sitting on the inner pipe string and able to rotate on it, one of them is movable along the longitudinal axis of the pipe string, and the second is stationary, the hydraulic monitors are hydraulically connected to the pipe string through the stationary sleeve, and the movable sleeve is connected to a spring device that regulates the position of the hydromonitors in the well, and nozzles are mounted in the hydromonitors, using one they erode the reservoir, via other to create a torque around the jetting hole axis.

This device allows you to:

- abandon the rotation of the inner pipe string during the erosion of minerals and the centering elements of the inner pipe string, which significantly reduces the material costs of mining;

- the pressure of the fluid supplied to the hydraulic monitors to regulate the number of revolutions of the hydraulic monitors, which expands the production area.

The proposed technical solution is illustrated by drawings, which depict:

figure 1 - stage of construction of a vertical well;

figure 2 is a stage of the construction of a production deviated well from a vertical parallel to the angle of incidence of steeply falling productive formation of minerals;

figure 3 is an intermediate stage of the method for downhole hydraulic mining at the stage of erosion of the reservoir;

figure 4 - the final stage of erosion of the reservoir;

figure 5 - diagram of the implementation of hydraulic mining during the construction of several (in this figure, three) production deviated wells from one vertical well;

figure 6 is a longitudinal section of a hydro-production projectile located in the production deviated well at the time of erosion of the reservoir;

in Fig.7 is a section of a hydraulic monitor according to aa in Fig.6.

Figures 1-5 show mineral 1 in the form of a steeply falling reservoir, covering the stratum of rocks 2, represented mainly by sedimentary deposits, stable rocks 3 and underlying rocks 4, as well as soils 5.

In the soil 5 and in the overburden 2, a vertical well 6 is constructed before the mineral 1 is opened. From a vertical well 6 using a deflecting tool (not shown) by a hydraulic production tool 7 using a bit 8 with an inertial expander 9, a production inclined well 10 is drilled. in practice, several similar wells can be constructed from one vertical well 6 (three such wells are shown in FIG. 5: 10, 11, 12) in different directions along the dip of the reservoir at the hanging side. The descent of the hydro-mining projectile 7 is carried out on the inner pipe string 13 while casing the inclined well 10 with the outer pipe string 14, and a hydraulic elevator (not shown) is lowered. Hydromonitors 15 hydro-mining projectile 7 erode mineral 1.

To do this, washing fluid is supplied through the inner pipe string 13 under pressure, which is supplied through the channels 23 to the hollow connections 21 to the hydromonitors 15 and flows out through the nozzles 28 and 29. When the fluid flows out of the nozzles 28, minerals are washed out, and when it flows out of the nozzles 29 there is a torque on the hydraulic monitors 15 around the longitudinal axis of the inclined well 10, which ensures the occurrence of centrifugal forces on the hydraulic monitors and causes their divergence to the sides of the longitudinal axis of the inclined well 10, i.e. ultimately, the diameter of the erosion of the well increases and thereby expands the zone of hydraulic production of mineral 1. The position of the hydromonitors 15 in the vertical well 6 is regulated by a spring device 2 and depends on the pressure of the supplied flushing fluid. In the process, the hydraulic projectile 7, the inner pipe string 13 may remain stationary.

Mineral 1 is washed out sequentially from the bottom up (arrow B in Fig. 3, this figure shows an intermediate stage 16) until the final stage 17, 18 and 19 (in Figs. 4 and 5) are obtained with the mineral pillar 20 being left behind 1 to ensure the safety of work.

A device for implementing the proposed method is shown in figures 6 and 7. It includes a hydraulic elevator (not shown), an internal 13 and an external 14 pipe string, a hydraulic mining projectile 7 mounted on an internal pipe string 13, a bit 8 with an inertial expander 9 is mounted at the end of this column The hydro-mining projectile 7 contains hydraulic monitors 15, which are connected through connections 21 and 24 to two bushings 22 and 25 sitting on the inner pipe string 13 and able to rotate on it, one of them 25 is movable along the longitudinal axis of the pipe string 13, and in torah 22 - stationary, the hydraulic monitors 15 are hydraulically connected through the stationary sleeve 22 to the inner pipe string 13, and the movable sleeve 25 is connected to a spring device 27 that controls the position of the hydraulic monitors 15 in the inclined well 10, and nozzles 28 and 29 are mounted in the hydraulic monitors 15 using the nozzles 28 erode the reservoir, and when the fluid flows out of the nozzles 29, torque appears on the hydromonitors 15 around the axis of the deviated well 10.

Thus, the proposed method of downhole hydraulic production and a device for its implementation provide a solution to the problem of increasing the efficiency of mining by reducing material costs, as well as increasing production as a result of the expansion of the development zone.

The present invention may find application in the development of deposits of KMA and other regions.

Claims (1)

A method of downhole hydraulic mining of a mineral, including opening a productive formation by a production deviated well, casing a pipe string, installing a hydraulic production projectile and hydraulic elevator in the well, jet washing out the formation, and raising the resulting hydraulic mixture of rocks with a hydraulic elevator to the surface, characterized in that in the thickness of the rocks covering the reservoir construct a vertical well before opening it; sequentially drill several production inclined wells from a vertical well zhin in different directions on drop formation at the trailing side, and are carried erosion formation minerals from the bottom up and at least a lifting gidrodobychnogo projectile casing pipe is extracted, well before the end of the erosion in the upper left portion of the wellbore rock pillar necessary security.

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