RU2478793C1 - Method of protection against logging of deep mines and pits with rising multibranch drainage wells - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method includes erection of vertical rising wells onto a drained water-bearing horizon, besides, from each rising well in a point located by 30-50 m below the water-bearing horizon soil, an additional side shaft is cut with a rounding (curve) radius of around 50 m. The side shaft is tunnelled after it reaches drained rocks in direction of the next rising well to the point of exit of the next additional shaft into drained rocks. It makes it possible to create a closed drainage contour and to practically eliminate ingress of underground waters into a protected mine or pit.

EFFECT: reduced ingress of underground waters to minimum permissible values.

2 dwg

Description

The invention relates to mining, and in particular to the development of waterlogged deep-seated mineral deposits.

From the modern technical level, a surface (shaftless) method of draining mines and mines is known, which consists in drilling beyond the outer boundary of the drained ore field of the barrage circuit of deep water-reducing wells equipped with borehole submersible pumps [Bolotskikh NS, Kuzkin B.C., Ponomarenko Yu.V. and other Handbook on drainage of rocks. M .: Nedra, 1984].

This well-known method of draining deposits is characterized by a number of significant drawbacks, which are most pronounced when draining deep mines and mines. The main disadvantages of this method include:

1) the need for drilling deep water-reducing wells;

2) the complexity of the design of the wells crossing the stratified layer of cover sediments containing several aquifers;

3) the need to equip the well with submersible pumps and the simultaneous operation of a large number of wells, which reduces the operational reliability of the drainage system;

4) the complexity of the energy supply of water-reducing wells;

5) the susceptibility of wells to damage or destruction when moving mining vehicles;

6) the need to leave a column of water in the water-reducing wells to create normal operating conditions (cooling) of the pumps, which does not allow achieving the required maximum reduction in groundwater level;

7) the possibility of penetration from the surface through the mouth of the wells of various contaminants into the drainage water and into intersected aquifers;

8) the need to drill wells when posting quarry sides;

9) a discrete arrangement of water-reducing wells, which leads to a breakthrough of groundwater between the wells and watering of mine workings, etc.

Currently, there is a better method for protecting mining from groundwater inflows, which has become widespread, is a closer analogue to the claimed method and is therefore adopted as a prototype. This method is a system (linear or contour) of rising drainage wells constructed from underground mining [Ponomarenko Yu.V., Volkov Yu.I., Kuzkin B.C. and others. The theoretical justification and advantages of the use of systems of rising drainage wells in waterlogged facilities. Materials of the 7th international symposium "Development of mineral resources and underground construction in difficult hydrogeological conditions." Belgorod, VIOGEM, 2003].

The method of draining deposits using systems of rising drainage wells is devoid of almost all the shortcomings of the surface drainage method, except for one associated with a discrete arrangement of drainage devices, and therefore allows groundwater to slip between the rising wells.

The objective of the claimed invention is to theoretically exclude the breakthrough of groundwater in the mine workings, and to practically minimize the flow of water to the mining site.

Technical results that can be obtained using the proposed method of protection against flooding of mines and mines are:

- in creating a diagram of the overlapping arrangement of drainage wells with the aim of completely crossing (blocking) the flow of groundwater moving to the mine workings, which will allow to build a closed drainage circuit system;

- in reducing the breakthrough of groundwater to the minimum acceptable values.

The solution of this problem and the achievement of the above results became possible due to the fact that in the known method of draining (prototype) deposits using systems of rising drainage wells from each of the main rising wells pass an additional lateral drainage trunk (right or left). Since the radius of curvature of the lateral shafts can vary from 30 to 50 m, the lateral wells must be laid in the water-resistant rocks underlying the drained aquifer at elevations that are 30-50 m below the flooded soil so that the horizontal branches of the lateral wells located near the soil of the aquifer, as shown in figure 1.

The curvature of the side wells during their drilling is achieved using the downhole motor and deflecting devices: a turbine diverter of the OTC type, diverter R-1, etc. [Kalinin AG, Levitsky A.Z. Technology for drilling exploratory wells for liquid and gaseous minerals. M .: Nedra, 1988].

The transition to the drilling of additional sidetracks is carried out using a downhole motor delivered to the bottom through a working casing string on drill pipes.

At the same time as the sidetracks are drilled by the downhole motor, a flexible (synthetic) filter is stretched by the downhole motor, the inner diameter of which exceeds the diameter of the downhole motor by 4 inches. In this case, drilling is performed with a destructive tool (tip), the drilling diameter of which is greater than the outer diameter of the filter by 4 inches.

The authors propose that the drainage system be constructed using only left or right additional side trunks by sinking. In this case, the lateral shafts from each main well pass to points B, C, D, in which the additional shafts exit from the underlying formation into a drained aquifer (Fig. 1).

The method of draining the aquifer, which is the main source of irrigation of mining, is as follows. At the beginning, from the underground mining 1, the main rising drainage wells are constructed, for example, 2, 3 and 4, revealing the drained horizon to the depth set by the project. Packers 5 are installed at the soil of the aquifer in each main well, temporarily blocking water inflows through the main wells 2, 3, and 4. From points A, sidetracks 6, 7, and 8 are drilled from the main wells, which respectively open the drained horizon to point B, C and D. Sidetracks, respectively, extend to the indicated points (B, C and D), which is necessary to create a closed drainage circuit and minimize the breakthrough of groundwater.

The most difficult task is to build wells in loose, irrigated and unstable rocks. In these cases, in order to ensure the stability of the walls of the wells, hypane drilling fluids are used [Bashkatov D.N. et al. Handbook of water well drilling. M .: Nedra, 1979].

After completion of the sidetracking of the additional well, the drilling tool is disconnected and used to close the well at the bottom to prevent fine earth entering the filter string. The downhole motor is removed along the wellbore, secured by a filter pipe. At the final stage, when commissioning the constructed drainage system, the installed packers 5 are removed.

The practical applicability of the claimed invention is shown in the following example. The side of the designed quarry in the KMA basin is considered as a drained object.

Six aquifers are widespread on the area of the field being developed (Fig. 2): in alluvial sands, found only in the river valley, in Neogene clay sands, sporodically distributed, Devonian and ore-crystalline horizons, mainly associated with rock formations. The main sources of waterlogging on the sides of the quarry are the Melo-Marl and Alb-Cenomanian aquifers. But the greatest difficulties in ensuring the stability of the sides are associated with the flooded sands of the Alb-Cenomanian horizon, the thickness of which sometimes reaches 35-40 m, and the filtration coefficient up to 10 m / day.

When developing a system for draining the Alb-Cenomanian aquifer at the stage of the fuel and energy complex, several alternative options were developed, including the option of draining the sands by rising wells with additional sidetracks constructed from underground mine workings.

According to the indicated option, the rising wells on the Alb-Cenomanian sands are planned to be drilled in a closed circuit with a pitch of 40-50 m, the sidetracks (right) were drilled approximately 40-45 m below the soil of the drained sands (see Fig. 1). At the same time, to create a closed drainage circuit and prevent groundwater from flowing aboard the quarry, lateral horizontal branches of the trunks are provided to extend to the exit points of adjacent side trunks into the Alb-Cenomanian sands.

Drilling of rising wells is planned to be carried out by the UDB-8-01 m drilling rig. Sidetracks are planned to be carried out using downhole motors.

The performed computational calculations and computer simulations showed that with the option of using rising wells without additional sidetracks, the penetration of groundwater into the quarry, for example, in the 8th year of development, will be 2500 m ³ / h with a total inflow of 5650 m ³ / h. According to the version with the use of rising wells with additional lateral shafts, the groundwater penetration into the quarry will not exceed ~ 550 m ³ / h.

Claims (1)

A method of protection against flooding of deep mines and mines with the help of rising multi-hole drainage wells, including the construction of vertical rising wells on a drained aquifer, characterized in that from each rising well at a point located 30-50 m below the soil of the aquifer, an additional a lateral well with a radius of curvature (curvature) of about 50 m, a lateral well pass after it enters the drained rocks in the direction of the next rising well to the exit point of the next additional tion of the barrel in the drained rock that allows you to create a closed drainage path and virtually eliminate leakage of groundwater into the protected mine or mine.

Images