RU2579855C1 - Method for elimination of degassing wells - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to controlling ventilation of high-efficiency cleaning of coal faces with system of deposit development by long columns in process scheme "shaft-bed". According to method in degassing wells drilled in coal pillar between parallel workings at development of coal deposits by long columns, set injection and control tubes. One prepares hardening solution or liquid chemical composition with given properties from condition of coal massif continuity and elimination of gas exchange between openings after hardening of said solutions or compositions. Through injection tube degassing wells are filled with said solutions or compositions on side of active workings upslope upward degassing wells in direction to parallel mines, spent working front face. At that, controlled complete at entire cross-section filling of degassing wells hardening solutions or liquid mineral compositions by check tubes and cracks in boards workings that crosses degassing wells in coal pillar.

EFFECT: increase in efficiency of elimination of degassing wells.

2 cl, 3 dwg

Description

The present invention relates to the mining industry, to the ventilation control of high-performance coal treatment slabs with a long-pillar field development system according to a “mine-formation” flow chart.

Appendix No. 24 to the “Instructions for the Degassing of Coal Mines”, approved by order No. 679 of the Federal Service for Ecological, Technological and Nuclear Supervision of December 1, 2011 (hereinafter referred to as the appendix), indicates that it is necessary to pre-seal the wellhead with cement sand mortar for subsequent effective degassing. The composition of the mortar is determined by the ratio of cement / sand = 1. Cement is used grade M500, according to the classification of GOST 31108 CEM I 42.5B. Paragraphs 5–13 of the appendix provide methods for sealing degassing wells with cement mortar. In terms of their technical nature, these paragraphs indicate the methods for performing the plugging of the annular annular space between the casing and the well for various conditions of the angle of inclination of the well (ascending or descending coal well), and the characteristics of the enclosing rocks through which the wells are drilled. The possibility and method of using cement sand mortar with a cement / sand ratio = 1 to fill a degassing well after completion of its operation in order to eliminate the well and restore the integrity of the coal mass in which the well was drilled is not indicated in the appendix.

From the existing level of technology and technology, a whole direction is known for eliminating deviated oil or gas wells by various cement grouts. The solutions are supplied from the surface to the well in various ways and fill the well from bottom to top. Cement grouts are made using various mineral or organic additives that give the grouts the desired properties to perform certain technical tasks in the construction, repair and liquidation of wells (Bulatov A.I., Daniushevsky BC Grouting materials. - M .: Nedra, 1987; Soloviev E.M., Completion of wells. M.: Nedra, 1979).

It should also be noted that in recent years, directions have been actively developing to create various building materials based on cements and dry building mixtures. These materials, due to the introduction of modifying additives (a complex of chemical and mineral additives) into their composition, make it possible, in particular, to build mortars with specified parameters: the start time of setting and the mobility of the mixture. For example, such a group of building materials as composite fine-grained concrete "Concrete Technology". Textbook. Yu.M. Bazhenov - M .: ASV Publishing House, 2002. The strength of materials obtained by adding modifiers and active components to cement sand mixtures, which in turn include super-thin active mineral components, can reach Rmax = 1230 MPa (maximum compressive strength ) with the ratio Cement / Sand = 1 paragraph No. 12.5 Table 12.2. "Concrete technology." Textbook. Yu.M. Bazhenov - M.: Publishing house ASV, 2002.

The technical problem to be solved by the claimed invention is directed to a method of effectively eliminating degassing wells drilled wholly between parallel openings when developing a coal field with long columns, restoring the integrity of the coal mass and eliminating possible gas exchange between parallel openings through the well and associated cracks in the whole without changing the technology of drilling degassing wells.

The problem was solved by filling the well from the side of the existing production with various solutions (cement mortars, cement sand mortars, solutions of liquid mineral compositions) with the specified properties: setting time, mobility, adhesion and others. In this case, degassing wells should be drilled at an angle within the reservoir thickness wholly between the workings, so that the wellhead is as low as possible to the production soil, from where the well will be filled, and the well bottom will be at the roof of the parallel production. The well is filled with solution from bottom to top in the uprising. At the same time, rising along the well, the solution evenly fills the well itself and the cracks associated with it in the coal mass. The set start time for setting the mortar is calculated based on the volume needed to fill the well and the productivity of the equipment used to fill the well with the mortar. After the solution hardens and gains strength, the integrity of the coal mass is restored.

SUMMARY OF THE INVENTION The most efficient from an economic point of view are coal mines producing coal according to the “mine-plast” technological scheme with a long-pillar mining system. Such a technological scheme allows the safe operation of high-performance treatment faces. With this technological scheme, in projects for ventilating the working faces, drilling of degassing wells in the whole of coal is provided between two parallel drifts for pumping the gas-air mixture while passing the treatment front of the lava along the pillar in which the wells are drilled. Wells are drilled of a certain diameter, for example, from 200 mm to 500 mm, and with a certain step, for example, from 5 m to 50 m. The gas-air mixture is pumped out from the worked-out lava space through wells through a degassing pipeline by pumping stations to the day surface of the mine. After the treatment front leaves, the degassing wells are disconnected from the degassing pipeline and tightly sealed to prevent gas exchange between the waste space and the existing production. In Fig. Figure 1 shows an example - a control scheme for ventilating a treatment area using degassing wells drilled wholly between workings.

The basis of the invention is the task of effectively eliminating wells after pumping out the air-gas mixture from the waste space to restore the integrity of the coal mass in its entirety between the workings.

To solve this problem, it is proposed to drill degassing wells at an angle within the reservoir thickness wholly between the workings, so that the well inclination ensures the maximum possible bottom hole position to the production roof, along which the lava treatment front will pass, and the wellhead is as low as possible to the production soil where the drilling comes from. After completion of the work on pumping out the gas-air mixture, the wells are filled with a solution (cement, cement, sand, liquid mineral composition) from bottom to top according to the uprising from the side of the wellhead, which is in the working hole. The solutions have the specified properties: setting time, mobility, adhesion to the rocks, and retain these properties until completion of the filling of the well. Since filling wells with solutions is possible using various equipment, additives are added to the solutions that allow them to be fed as efficiently as possible to the wells for each specific equipment. When the solution is fed into the wells, they evenly, from the bottom up, fill the well and the cracks associated with it, due to its mobility and adhesion properties. After filling the well for a certain time, hardening of the solutions occurs with a simultaneous increase in the specified strength. As a result, the integrity of the coal mass in the place where the well is drilled is restored.

In fig. 2 shows a layout of a degassing well prior to the start of a production face advance.

Well 1 is drilled from drift C to drift B at an angle that is technologically possible to provide with a drilling rig from the conditions: the lowest possible location of the wellhead to the drift soil C; drilling cutter drilling at roof level in drift B.

In fig. 3 shows a well filled with a solution from the side of an existing mine.

The proposed method allows you to effectively eliminate degassing wells, restore the integrity of the coal mass with solutions with specified properties (cement, cement sand or liquid mineral compositions). With this method, in principle, the technology for drilling degassing wells as a whole between parallel workings does not change, and, accordingly, the worked out effective control schemes for ventilating high-performance treatment faces do not change. Also, this method allows you to use a large list of building materials used in surface construction, introducing special additives into them for supplying solutions to liquidated wells prepared on the basis of these materials, using equipment approved for use in underground coal mines.

The proposed method was used to eliminate degassing wells No. 331, 332, 333, 334, 335, 336 at one of the coal enterprises in the Yerunakovsky coal mine of Kuzbass. The enterprise was built and operates according to the “mine-plast” technological scheme with a long-pillar development system along strike. To eliminate air drainage between two parallel operated openings through a pillar of coal within the boundaries of the geological disturbance zone, a technical solution was proposed to fill inclined degassing wells No. 331, 332, 333, 334, 335, 336 with solutions (cement, cement sand and liquid mineral composition) to a length of 17.5 along the strike of each well from the side of the wellhead.

The wells were filled: No. 331, 332 - with cement sand mortar (based on the dry mix SUTSPSUSH TU 5745-002-50576573-2014); No. 333, 334 - cement mortar (based on cement cement PTC I-50); No. 335, 336 - with the non-combustible lining liquid mineral composition TU 5772-004-50576573-2014, using the PNT-1 pump unit. Injection and control (composite) plastic tubes with a diameter of 30 mm were installed and sealed in the well. Dry mixtures based on cement, cement and sand were closed with water, mixed in a mixer of the PNT-1 pump unit (a liquid two-component composition was simply poured and mixed in a mixer). Then the solutions were supplied via an injection tube 3 meters long into each well under a pressure of up to 15 bar, while some of the solutions flowed out through cracks in the production side. The full (over the entire cross-section) filling of the well was checked to a length of 17.5 m using a composite tube with a total length of 21.5 m.

After the work was done to fill the wells with solutions for their liquidation, the air drainage stopped.

Literature

1. “Instructions for the degassing of coal mines”, approved by order No. 679 of the Federal Service for Ecological, Technological and Nuclear Supervision of December 1, 2011.

2. Bulatov A.I., Danyushevsky B.C. Grouting materials. - M .: Nedra, 1987.

3. Soloviev EM Well completion. M .: Nedra, 1979.

4. Concrete technology. Textbook. Yu.M. Bazhenov - M.: Publishing house ASV, 2002.

Claims (2)

1. A method for the elimination of degassing wells, characterized in that injection and control tubes are installed in the degassing wells drilled in the whole coal between parallel workings during the development of coal deposits with long columns, hardening solutions or liquid mineral compositions are prepared with the specified properties from the condition of restoring the integrity of the array coal and eliminate gas exchange between workings after the solidification of these solutions or compositions, through injection tubes The wells are filled with the mentioned solutions or compositions from the side of the working openings from the bottom upwards along the uprising of the degassing wells in the direction of the parallel workings worked out by the lava front, while the complete filling of the degassing wells over the entire cross section with hardening solutions or liquid mineral compositions through control tubes and cracks is controlled on the sides of openings crossing degassing wells in the whole of coal. 2. The method according to p. 1, characterized in that as hardening solutions use cement mortars or cement sand mortars.

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