RU2320874C2 - Method for pit protection against underground water inflow - Google Patents

Abstract

FIELD: mining and pit protection against underground water inflow in the case of open-pit kimberlite pipe and other mineral deposits development in subpermafrost horizon.

SUBSTANCE: method involves discharging water initially contained in deposit section to be developed and precipitation water from said deposit section; drilling injection wells around kimberlite pipe perimeter and from pit bottom; performing explosions in wells surrounding kimberlite pipe perimeter and carrying-out hydraulic fracturing from wells drilled from pit bottom to create jointed subvertical and subhorizontal rock fissured zones, which have uniform fissures; supplying plugging materials therein and creating joined solid watertight diaphragms shaped as integral cups.

EFFECT: possibility to create watertight diaphragm, which protects deposit section to be developed against underground water ingress.

Description

The invention relates to mining, in particular for protecting quarries from the influx of groundwater during open pit mining of kimberlite pipes and other mineral deposits in the permafrost (aquifer) horizon.

There is a method of protecting quarries in these conditions, including drainage - pumping or drainage of groundwater entering the quarry with their direction through a system of pipes with pumps into open reservoirs or underground aquifers of deep occurrence [1]. Prototype.

The disadvantages of this method are:

the need to create a complex system of outlet pipes with pumps and wells for pumping water entering the quarry into deeper reservoir horizons directly below the field being developed or lifting water upwards with its subsequent transportation through pipes for discharge into open reservoirs, if possible for environmental reasons, or injections into deeper reservoir horizons at a distance from the field;

the need, often, to move huge volumes of water, measured in hundreds of thousands of cubic meters.

The technical task is to create a continuous waterproof curtain, protecting the developed part of the field from further groundwater inflows, and drainage of underground and rainwater originally contained in it.

A method is proposed for protecting a part of a kimberlite pipe or other mineral deposits developed in the permafrost horizon from an underground water influx, including the drainage of initially contained, including those coming from sediments, in the part of the water field planned for development, which consists in drilling injection wells along the perimeter of the kimberlite pipe and from the bottom of the quarry, explosions in the wells along the perimeter of the kimberlite pipe and hydraulic fractures from wells drilled from the bottom to the open-pit mine create jointed subvertical and subhorizontal zones of high-fracture rocks that are homogeneous by this feature, supply grouting materials to them under pressure and create interlocking continuous waterproof anti-filtering curtains that form a single unit in the form of a glass.

Introduced into the claims is such an essential feature that previously injection wells are drilled along the perimeter of the quarry, subsequently by explosions in them, it is possible to create a subvertical annular zone of highly fractured rocks, uniform in this feature.

Introduced into the claims is such an essential feature that previously injection wells are drilled from the bottom of the quarry, it subsequently allows fracturing to create a subhorizontal zone of rocks of high fracture, uniform in this feature.

Introduced into the claims is such an essential feature that plugging materials are fed under pressure into pressure-fractured zones of high fractured rocks through injection wells and, after hardening, receive joined subvertical and subhorizontal continuous monolithic waterproof antifiltration curtains.

The method is as follows. On the perimeter of the kimberlite pipe, injection wells are drilled from the bottom of the quarry to the design depth, by explosions in the first and hydraulic fractures in the second, they create subvertical and subhorizontal zones of rocks of high fracture, uniform in this sign, joined and hydraulically connected. Then, through the injection wells, grouting materials are supplied into them under pressure, after hardening of which a continuous, monolithic waterproof antifiltration curtain in the form of a cup is formed, inside which the worked out part of the field is located. It is preferable to use plugging materials that are not susceptible to the damaging effects of aggressive groundwater and whose volume during solidification increases, which contributes to a better filling of the pore space. The distance between the wells along the perimeter of the kimberlite pipe is chosen so that during explosions in two neighboring wells, a homogeneous zone of fractured rocks is created between them. To create a subhorizontal zone of rocks that is homogeneous in degree of fracture, it is possible to carry out a series of hydraulic fractures, introduce liquid explosives into this zone and burst them. The degree of homogeneity of the fractured zone prior to injection of the solution can be estimated using geophysical studies in wells, in particular, by measuring successively the resistance between the electrodes in two neighboring wells, which will be filled with water under the considered conditions. In areas with high resistance and, consequently, a relatively lower degree of rock destruction, explosions should be repeated to increase their fracturing. The presence of a hydraulic connection between the subhorizontal and subvertical zones of highly fractured rocks can be established by known methods: by feeding solutions with various indicators — salts, dyes, radioactive isotopes — into the well at the bottom of the quarry and controlling their entry into the wells along the perimeter of the quarry. The waters that were initially contained in the rock volume isolated by the anti-filter curtains and entering the quarry with precipitation are removed by known methods of drainage and / or drainage.

The advantage of the proposed method is to create a reliable antifiltration curtain in the form of a glass that isolates the mined part of the field from the influx of groundwater.

Information sources

1. Mountain Encyclopedia, Volume 1. - M .: Publishing House. "Soviet Encyclopedia", 1984. p.407.

Claims (1)

A method of protecting a part of a kimberlite pipe or other mineral deposits developed in the permafrost horizon from an underground water influx, including the drainage of initially contained and including those coming with sediments, in a part of the water field planned for development, characterized in that injection wells are drilled along the perimeter of the kimberlite pipe and from the bottom of the pit, explosions in the wells along the perimeter of the kimberlite pipe and hydraulic fractures from the wells drilled from the bottom of the pit, create ostykovannye subvertical and high sub-horizontal fracture rocks zone homogeneous on this basis is supplied to them under pressure grouting materials and create watertight mating solid curtain, forming one piece cup-shaped.