Method for development of series of contiguous coal beds

FIELD: mining.

SUBSTANCE: method consists in identification of a length of active gas release zones, preparation of extraction pillars by tunnelling and strengthening mines in the rock massif, mining of extraction pillars and removal of methane in degassing wells. At the same time the length of active gas release zones is defined by variation of volume deformations of rock massif. At the same time the values of volume deformations of rock massif are produced by numerical methods on the basis of analysis of components of deformation and stress tensors with account of the time factor. The tensor characteristic is gas permeability of rocks under conditions of their natural occurrence. Medium values of rock massif gas permeability are assessed by the given mathematical expression. After determination of length of active gas release zones, with account of produced data, schemes of well drilling, their diameter and number are selected.

EFFECT: increased efficiency of methane removal, higher load at a working face and increased safety of clearing works by gas factor.

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The invention relates to mining, in particular to systems development contiguous vysokogazonosnyh coal seams, and can be used to increase the load on the longwall face and enhance the security of wastewater treatment works on the gas factor.

A known method of degassing of coal-bearing strata (RF patent No. 2103516, E21F 7/00, publ. 27.01.1998). Method of degassing of coal-bearing strata includes the driving of the drainage generation in the roof and the soil of the reservoir prior to the start of preparatory workings on the protected reservoir and the installation of temporary supports in the development. Drainage production are removed from the protected reservoir, not exceeding 8,5 multiple of the width of the drain output. Its soil is placed a perforated pipeline, then obresult production, and the driving of the development workings on the protected reservoir begin after reducing gas magazinemore area to a safe level.

The disadvantage of this method is the low removal efficiency of methane, reducing load on the longwall face and the high risk of treatment works due to the influence of the gas flow.

A known method of degassing of coal-bearing strata (RF patent No. 2382882, E21F 7/00, publ. 27.02.2010). The method includes the driving of the drainage generation in gas-bearing formation-satellite away from the protected reservoir before Prov is Denia development workings on the protected reservoir. Pass it in a plane parallel to the boundaries of the mining of pillars in the area bounded by the lines of the actual angles of faults and angles of displacement, designed from the ground workings of the protected layer. Use it as a degassing pipe, separately ventilated due to the mine of the depression, and the maximum height h between the reservoir-companion and protected by a layer of vertical take less than 40 m. The minimum capacity of the reservoir companion take more than 0.2 m, where m is the capacity of the protected layer.

The disadvantage of this method is the low removal efficiency of methane, reducing load on the longwall face and the high risk of treatment works due to the influence of the gas flow.

There is a method of integrated development of the area of the coal field (RF patent No. 2370649, E21C 41/18, E21B 43/295, publ. 07.04.2008). The way the comprehensive development of the area of the coal field includes: a preliminary degassing reservoir, dissection and preparation of a mine field by conducting network opening and preparing the mine workings with the General bias towards major trunks for the organization gravity drainage, supply of the necessary quantity of air for forced ventilation in one direction, the cutting of coal and transportation of extracted coal to the surface in the same forges the workings. As the dredging of coal part of the mine workings in the waste part of a mine field continue to support until the end of its development. After the extraction of coal in the mine field carry out underground burning of the security pillar, operational losses and substandard coal reserves. After burnout of the coal in the mine field remains gaseous products of underground combustion concentrate on the upper horizon of a mine field by completing just a goaf aqueous solution of reagents. Gaseous products of underground combustion capture on the upper horizon of a mine field and, after extinguishing the hearth underground combustion, carry out pumping productive solution from the sump of the shaft. The pregnant solution is directed to the extraction of valuable and (or) toxic elements, and filling out space aqueous solutions of the reagents and their pumping produce repeatedly if necessary, shift reagent.

The disadvantage of this method is the low removal efficiency of methane, reducing load on the longwall face, and a high risk of treatment works due to the influence of the gas flow.

There is a method of developing a Suite of contiguous vysokogazonosnyh coal seams adopted for the prototype (patent RF №2282030, AS 41/18, E21F 7/00, publ. 20.08.2006). the manual development of the Suite of contiguous vysokogazonosnyh coal seams involves testing one of the first and including the preparation of the mining of pillars by holding and fastening the conveyor and ventilation workings, leaving the coal pillar between the conveyor generation working on the excavation of the post and ventilation development subject to the development of the mining of the pillar, holding the vent sbec between conveyor production working on the excavation of the post and ventilation development subject to the development of the mining of the pillar, the refinement of each extraction column with simultaneous installation of security supports in supported for clearing face on the border with goaf side of the conveyor production and construction in ventilation zboyco from goaf jumper and removing methane gas from the goaf means of ventilation with flow methane-air mixture generated by the leakage of air issued from the stope through the goaf at the expense of mine depression supported in part pipeline generation and podziemie it, and shared the nearest for clearing face ventilation breakthrough into two parts, one of which follows this linkage and further develop ventilation, as outgoing excavation site podviganiem on it, and simultaneously with the removal of methane by means of ventilation shall exercise its removal from the goaf means of degassing by kartirovanija is another part of the flow methane-air mixture, flowing through the worked-out space near the unsupported part of the conveyor generation, degasification wells drilled in undermining the array of ventilation generation towards the goaf, and according to the invention initially determines the length of the active zone of outgassing undermined and narabatyvaem contiguous coal seams, and then as a longwall pillar for clearing face in pipeline development in the areas of active gas undermined and narabatyvaem contiguous coal seams build gas gathering manifold by-turn construction of two transverse ridges, the ends of which extend beyond the contour of the conveyor output, and each of the transverse bridges erected in pipeline development from goaf ahead of the next vent breakthrough after firing clearing face the following ventilation breakthrough with simultaneous superepicawesome ventilation breakthrough inserted between previously constructed adjacent nearest from the stope jumpers, while the nearest of stope jumper gas gathering manifold come from him at a distance equal to not more than the length of the zone of active gassing narabatyvaem contiguous coal the seams, and the other more remote from the stope jumper - respectively at a distance equal to not more than the maximum length of the zone of active gassing narabatyvaem contiguous coal seams, and as podvigina stope remove methane gas from the goaf means of degassing occurs in two stages: the first part of the flow methane-air mixture, which should be worked-out space near the unsupported part of the conveyor output, one's pressing away in the zone of influence of each of the transverse crosspieces gas gathering manifold in the direction of arrangement of the upper layers of the discharge zone undermined contiguous coal seams, due to which there is an abrupt increase in the concentration and flow rate of methane-air mixture specified part of the stream, which then captious by degasification wells and the drilling of these wells in undermining the array of ventilation generation towards the goaf them oriented so that each hive degasification wells were in the zone of influence of the transverse crosspieces gas gathering manifold, further followed by podvigina stope during longwall pillar repeat the cycle of works on construction of the next gas gathering manifold when using the next to swedeneu jumpers the nearest from the stope to the newly formed leap concentration and flow rate of methane-air mixture, with subsequent extraction of the goaf use the degasification wells, after the preparation of regular excavation post in one of the suites are contiguous vysokogazonosnyh coal seams and testing it in the Suite of the first in the area of undermining or nudebody work related contiguous coal seams using traditional development techniques used in the context of low residual natural gas-bearing coal seams.

The disadvantage of this method is the low removal efficiency of methane, reducing load on the longwall face, and a high risk of treatment works due to the influence of the gas flow.

The technical result of this method is the efficiency of removal of methane, the increased load on the longwall face and enhancing the security of wastewater treatment works on the gas factor.

The technical result is achieved in that in the method development Suite contiguous vysokogazonosnyh coal seams, including the determination of the length of the active zone of outgassing, the preparation of the mining of pillars by holding and fastening the conveyor and ventilation openings through the array of rocks, testing, excavation is elbow, destruction of methane degasification wells according to the invention the length of the active zone of the gas is determined by the change in volumetric strain ΔΘ of rock mass using the dependency:

ΔΘ=Θ0i,

where: Θ0volumetric deformation of the rock mass prior to the longwall pillars; Θivolumetric deformation of the rock mass at the i-th stage of a longwall pillars, the strain values Θ0and Θirocks get numerical methods based on the analysis of the components of the tensor of deformations and stresses taking into account the time factor, and the tensor characteristic is the permeability of rocks in the natural conditions of their occurrence, and to estimate the average values of the permeability kcprocks use the expression:

kwith ap=k0with ap+aσwith ap;

where:k0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σcf→0, σcf - the average operating voltage working in the rock mass, kg/cm2;athe empirical factor when determining the length of the active zone of the gas taking into account the received data select circuits drilling, the diameter and number.

The method is intended primarily for testing suites vysokogazonosnyh coal seams modern mechanized complexes. The mining of the coal-bearing strata, usually accompanied by a large discharge of explosives and flammable methane gas, which in the extraction of coal put restrictions on the load on the longwall face, the so-called gas vent barrier. Currently, due to the significant depth of mining is allocated an increasing amount of methane (for example, the average gas mines in Donetsk and Karaganda basins, respectively, 30 and 90 m3/min). To deal with such quantities of methane in the traditional way (dilution of methane and air removal from the mine ventilation air) in many cases is not possible due to the necessity of submission to the mine is extremely large amount of air and exceeding the permissible speed of its movement through the workings in accordance with the requirements of applicable safety Rules in coal mines. The increase in the rate of podvigina La is on the layers with high gazoobilnostju and the expansion of the scope of complexes with hydraulic roof supports require the adoption of more effective measures to reduce gazoobilnosti. Existing methods preliminary degassing of producing reservoirs wells and improving the degassing goaf often do not provide the reduction of gazoobilnosti to an acceptable level, since the largest amount of gas is released in the mined-out area of the seam satellites.

Studies have shown that the length of the active zone of outgassing can be performed using calculation methods that take into account the change of the filtering capacity of the rock mass (including retinue vysokogazonosnyh coal seams) in the process of changing its state of stress (redistribution of stresses in the rock mass). This quantity is the parameter that characterizes the change of the volumetric strain ΔΘ in point of rocks, namely:

ΔΘ=Θ0i,

where: Θ0volumetric deformation of the rock mass prior to the longwall pillars; Θivolumetric deformation of the rock mass at the i-th stage fulfil extraction columns.

The values of the volumetric deformation of a rock mass can be obtained by numerical methods based on the analysis of the components of the tensor of deformations and stresses taking into account the time factor. To estimate the permeability of a rock mass, depending on its mechanical condition of use exp is a provision:

kwith ap=k0with ap+aσwith ap;

where:k0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σcf→0, σcf- the average operating voltage working in the rock mass, kg/cm2;a- an empirical coefficient. Considering the obtained results, select the diagram and place the drilling degasification wells for efficient removal of methane from the Suite vysokogazonosnyh coal seams.

The total porosity of coals on average can reach ~ 12%, but since it usually consists of sorption and filtration volumes, its last component (effective porosity) reaches ~ 3%. These volumes are usually represented pores (cracks) with sizes ranging from 10-6up to 10-1cm, forming a complex system of inter-connected transport channels (cavities). These values meet the condition, when the rock mass containing the retinue vysokogazonosnyh coal seams is unloaded from the mechanical stress state σ cf→0). Preliminary estimates showed that the presence of external loads, responsible geostatistical field ("γ·H") to a depth of ~ 1500 m, insignificant effect on the change of the sorption volume of coal, mostly, ultrapure, and to change their filter porosity.

The study of the variability of the actual mountain-geomechanical parameters of any of the evaluated object can be accomplished by the apparatus of the boundary element method, finite element method, and others.

Developed for numerical experimentation methodology of evaluation of the stress-strain state (SSS) of the rock mass (IHL) provides data on the parameter ΔΘ as a function of coordinates (space). Asking some fixed (for specific moments in time) the position of the front of the treatment works, it is possible to obtain the functional dependence of the desired parameters from time to instantiations in consideration of the deformation of the strata of rocks in terms of specific tasks.

The researches have shown that there is a correlation parameter effective porosity n and the average values of stresses σcfoperating in the rocks. Therefore, in the quasi-elastically-deformable environments obvious and interdependence of the parameters n and Θi.

ΘiK·σ cf,

where: K - parameter (K=3/E·(1-2·Θ·iµ)); E is the modulus of elasticity of structural lithotypes of the rock mass; µ is the Poisson's ratio of the same elements of the array of rocks.

This allows you to define the role of VAT rocks in the change in the effective (filter) porosity, i.e. the permeability of the medium can be expressed as follows:

kwith ap=k0with ap+aσwith ap;

where:k0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σcf→0, σcf- the average operating voltage working in the rock mass, kg/cm2;a- empirical coefficient.

Method development Suite contiguous vysokogazonosnyh coal seams is as follows. Prepare extraction columns by holding and fastening the conveyor and ventilation openings on the rocks. Work excavation posts. Remove methane means of ventilation due to mine depression and degasification wells is m Before you begin preparatory work to determine the length of the active zone of the gas in coal seams by calculation according to the change in volumetric strain ΔΘ array of rocks on the basis of correlation between the reservoir and the filtration characteristics of a rock mass with its mechanical condition with dependencies:

ΔΘ=Θ0i,

where: Θ0volumetric deformation of the rock mass prior to the longwall pillars; Θivolumetric deformation of the rock mass at the i-th stage of a longwall pillars.

Values of volumetric strain Θ0and Θ rocks get numerical methods based on the analysis of the components of the tensor of deformations and stresses taking into account the time factor, and to assess the permeability of the filtering medium, depending on its mechanical condition using the expression:

kwith ap=k0with ap+aσwith ap;

where:k0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σ cf→0, σcf- the average operating voltage working in the rock mass, kg/cm2;a- an empirical coefficient. Taking into account the received data select circuits drilling, the diameter and the number for the effective removal of methane from the Suite vysokogazonosnyh coal seams.

It should be noted that this technique can be used to calculate the filtration characteristics of the zones of the rock mass that experiences only elastic deformation, i.e. zones of caving and fracturing need to use other approaches.

The implementation of how the development of a Suite of contiguous vysokogazonosnyh coal seams is illustrated by example for the formation of the "Fourth" of the Pechora coal basin. Figure 1 shows a mountain-geomechanical model of a rock mass to estimate the stress-strain state of rocks in narabatyvaem layer of the Fourth array of rocks, figure 2 shows the graph of the function kcp=φ(σcfto estimate changes in the permeability of the rock mass, figure 3 shows part of the scheme assessment area parameter "ΔΘ" in narabotano array "n11-n7"that figure 4 shows the zoning variability geomean-gas-dynamic properties narabatyvaem mitoplast "n11-n7", "A", "B", "C", "D", "D", "E", "W", "3", "B" and "A" - active zone is about gassing in the rock mass, figure 5 shows the graph of the function ΔΘ=f(Θi) when values: ΘAo=-62·10-5(meets the conditions nudebody mitoplast "n11-n7"); ΘJSC=-30·10-5- alternatively family ΔΘ=f(Θi), figure 6 shows a variant of the degassing circuit for narabatyvaem mitoplast (n11-n7) (gentle deposition of layer "n11", the descending order of testing columns).

Figure 1 area of nudebody meets the limits of the area (So(square outcrops to the 1st landing of the main roof), SII(area of exposure to the following planting of the main roof), and the time factor is characterized as t→t1, ti≥tn(t is the time factor, characterizing the time elapsed from the beginning of mining lava, t1- time factor, characterizing the time during which peregruzhennoe goaf gaining the maximum area before the collapse, ti- time factor, characterizing the time elapsed from the beginning of mining lava to achieve the calculated area a, B,..., tn- time factor, characterizing the time elapsed from the beginning of mining lava before planting the main roof). On the border of the studied weightless field applied pressure P≈γ=25 MPa. Area studies of the parameters of the stress-strain state of the array: 0≤x≤160 (m)of-1.6≤y≤-83 (m), that is fully "ovative the t narabatyvaem thickness (including the layer of n 7). "1-1" - symmetry axis.

For practical (approximate) estimates of changes in effective porosity in the array can be used a simple approximation of the function n=f(σcp) in the form:

kwith ap=k0with ap+aσwith ap;

where:k0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σcf→0, σcf- the average operating voltage working in the rock mass, kg/cm2;a- empirical coefficient (~ 52·10-4).

It should be borne in mind that the stress values for the conditions σcf>0 in narabotano rocks is limited.

The permeability of rocks in the natural conditions of their occurrence is the tensor characteristics. Understanding the variability of this parameter in a function of the mechanical stresses in the array can be derived by analyzing the average (for a given point of rocks) parameter values, i.e. in the form of kcp=φ(σcf).

The results of the study of gas permeability is verbal formations (IGD, McNeil) showed that for coal grades "To" - "W"k0with ap(when σ→0) is about 60 ąd when the coefficient of variation V≤30% (≈0,06·10-8cm2), and the nature of the functions kcp=φ(σcffor all investigated types of coals can be represented in exponential form.

For estimates of the variability of the permeability of the array "n11-n7", narabatyvaem layer "Fourth", in first approximation, can be used to approximate equation of the form:

kwith ap=k0with ap+aσwith ap;

where: ±σcf- kgf/cm2;k0with ap- ąd (for indicative calculations can be made 60 ąd); 30≤k0with ap≤65,a=104·10-3.

The range of values of kcp=φ(σcfwhen using the above relationship does not exceed 30%. The graph of the function kcp=φ(σcfto assess changes in the gas is resizemode narabatyvaem layer "Fourth" midplate "n 11-n7" are shown in figure 2.

Using methodological approaches above will provide field increments (changes) volumetric deformation in the form:

ΔΘ=Θ0i,

where: ΔΘ is the change in volumetric deformation of a rock mass; Θ0volumetric deformation of the rock mass prior to the longwall pillars; Θivolumetric deformation of the rock mass at the i-th stage of a longwall pillars (these conditions correspond to the schemes: a, B, C, D, e, F, G, C, B, a, figure 4).

Information about the fields ΔΘ allows unambiguously (relatively with fields Θ) to evaluate the geomechanical and gas-dynamic state narabotano strata of rocks. Previously it was an order of this assessment, characterizing the orientation changes of reservoir properties of rocks depending on parameter change ΔΘ. In particular, the growth of value ΔΘ module in the conditions of dense (but if ΘiJSCor stretched zones of rock mass defines the "state" of discharge of the array when ΔΘ<0. Have in mind that the "unperturbed" array (not nakabatay) is initially in a compressed area, i.e. we have the values: ΘJSC=-62·10-5, ΔΘ=0. Other initial values ΘJSCthat meet the new zero value ΔΘ will be the corresponding dependences of Δ is=f(Θ i). For the considered conditions, in particular when ΘJSC=-62·10-5, this dependence is shown in figure 5.

Obviously, the growth of positive values ΔΘ (ΔΘ>0) meet the conditions prigruzki array from state0.

Field analysis ΔΘ showed the following. When the retreat longwall face from the mounting output distance up to 40 m in rocks, soil lava at depths from the first meters to twenty meters or more growth module parameter ΔΘ (assuming ΔΘ<0)that satisfies the conditions of unloading of the rock mass, the last in the square extends to depths from a few metres to twenty (or more) meters, i.e. it can reach the layer "n8" (unloaded a significant part of mitoplast "n11-n8"). Given technological parameters of production this discharge will occur at a distance of ~30 m from the mounting chamber, i.e. after ~10 days from the beginning of primary podvigina stope.

Upon further withdrawal of lava from a split furnace at a distance of 50÷60 m discharge zone reaches a depth of thirty meters ("n11-n8"), extending almost over the entire area of the developed space formed at the point in time up to ~20-25 days. On the time interval (10-25 days) module parameter ΔΘ continues to grow, and to the greatest extent within megaupl the joy "n 11-n10".

Further, up to a distance of about 300 m from the mounting chamber (time range up to ~90 days) traced the growth of /ΔΘ/ width goaf at the highest intensity along the goaf areas adjacent to the excavation drifts (up to 30 m in plan). Taking into account the widely used method of mining pillars (along strike) in descending order, it should be noted that in the present case, the highest value changes of the pore volume in narabotano thicker rocks will take place (in addition to acrostically region) within the lower part of the goaf, counting from the conveyor drift (at distances of ~(0,5÷0,7)Ll). The depth of discharge covers the seam parting "n11-n7" along the roadway, changing to the depths of "n11-n8(n9" in toward the center generated.

At distances from the mounting chamber over ~300 m (up to ~400 m) in narabotano thicker, the effect remains the elastic recovery of volumetric porosity within mitoplast "n11-n8" (to ~30-35 m depth). By the time it meets the range(85÷90)-(110÷120) days.

Next (>400 m) in narabotano the seam parting under the goaf and starts, to the time of departure lava 600÷700 m from the mounting chamber, practically ends with the restoration of IP is one of the pore space of rocks mitoplast "n 11-n7" (/ΔΘ/→0). The exception is calostemma area (up to ~20 m), in which there is a partial unloading of rocks in the seam parting "n11-n9" (/ΔΘ/≠0). With the same distance (~600÷700 m) on the main square goaf restores the pressure on the soil of layer "n11" (~γ·N), and therefore approximately the original (before the "perturbations" of rock to lava) state species of mitoplast "n11-n7"ie /ΔΘ/→0. However, along the moving lava in its soil is unloading rocks: almost "full" to a depth of 10÷15 m ("n11-n10") and partial (up to ~50%) at depths up to ~55 m ("n11-n7"), which is characterized by a rather large, as in the first case ("n11-n10"very sharp increase in modulus /ΔΘ/ of approximately twenty meters zone VP, measured from the plane of the longwall face. The beginning of the period under consideration in the time range corresponds to ~130÷140 days.

Established zoning unloading narabatyvaem layer "n11" the strata of the rocks causes and change their effective porosity. Changes the permeability of the rocks that you must consider when choosing parameters degassing considered mitoplast.

The distribution scheme of the mentioned zones within the goaf extraction column, working on prostran the Yu (in descending order), shown in figure 4.

Changes in the indices (Δn is the change in effective porosity, %; the average values of the permeability kcprocks, %) are given relative to the characteristics of the "unperturbed" treatment notch array, indexed "0th" mark: n0≈1.7 percent;andk0with ap≈34 ąd with a corresponding value of ΘJSC=f(σcf), is equal to ~ (-62·10-5).

For practical (approximate) estimates of changes in effective porosity in the array can be used a simple approximation of the function n=f(σcp) in the form:

n=n0+52·10-4·σcf,

where: ±σcf- kgf/cm2; n0- % (~3%); 1,5≤n≤3,5(%).

It should be borne in mind that the stress values in narabotano IHL limited.

As podvigina lava from mounting the camera at a distance of up to 70÷80 m (i.e. ~20÷25 days from the beginning of sewage extraction) begins unloading mitoplast "n11-n7"accompanied by a growth in Δn and Δkcp: ~1÷2% to ~5÷30% in depths of mitoplast "n11-n9(n8)" (area "a", "B", figure 4).

Further, the distances from 70÷80 m to 120÷150 m from the mounting chamber (zone "B", "C", figure 4) in the rocks of the soil in the area of the Central part of the goaf (and higher uprising place is a) starts decreasing values of Δn and Δk cp: up to ~30% in the rocks of mitoplast "n11-n9" and to ~10% in the seam parting "n9-n7". While doing cleaning work to this point is about 50 days.

In the zone from 120÷150 m to ~180 m below the Central part of the EAP is the process of further reduction of the values of Δn and Δkcpup close to the values of the background (unperturbed) state array. In area "G" (figure 4) in the region adjacent to the conveyor drift in the range of mitoplast "n11-n8"parameter values Δn and Δkcpcharacterized by the values (5÷15%), and in the seam parting "n8-n7" - (2÷8%). In the direction of the longitudinal axis of symmetry of the EAP until the distances from the roadway, the components of ~0,33 Llaccordingly, in the above packages, the parameters Δn and Δkcpchange within: (15÷30%) and (2÷10%).

In zone "D" (figure 4) at a distance of about 200 m from the mounting chamber (180÷200 m - 60÷65 days of doing cleaning work) along the roadway in the rocks of mitoplast "n9-n7" considering the magnitude of change from ~1% to ~(7÷8%) (bottom-up), and in the seam parting "n11-n9""- $(10÷15%). At distances <0,33 Llfrom the roadway (in the direction of the center EAP) changes Δn and Kcfrespectively for the same midplate, will be: (2÷10%) and (15÷25%).

Subsequent changes of reservoir properties of rocks in the zone "E", "W" and "3" have the t pronounced decrease of the values of Δn and Δk cphow in the direction of podvigina lava from the mounting chamber, and in the normal direction. In the first case, considering the seam parting "n11-n7"these changes are from (2÷5%) (at a distance of ~200÷250 m from the mounting production at the time ~70 days from the start of the dredging of the reservoir) to (1÷2%) (at a distance of ~550÷600 m from the Assembly output of approximately 180 days from the start of the dredging of the reservoir). The "lower" values (1÷2%) changes in effective porosity and gas permeability are responsible bundle of rocks mitoplast "n9-n7"and "upper" (2÷5%) - mitoplast "n11-n9(n10)". Normal to the roadway at a distance of ~0,2 Llfrom him, under the goaf is restored approximately "background" features previously narabotano mitoplast. The state in acrostically" the area remains stable and forth (over 350÷400 m) along the goaf up to the area "B"-"A" (figure 4) near the bottom space of the current "present" time of lava.

At a specified distance (>550÷600 m, i.e. at the time ~180÷200 days) in zone "B"-"A" (figure 4) change the parameters Δn and Δkcpremain next stable and inverse considered when departure lava from the mounting chamber (area "A"-"B" in figure 4). From a distance of 60÷70 m from the plane of the lava and continue towards her for the HH are the following changes:

- in the seam parting "n9-n7" the decrease from ~30÷5% to ~2÷1%;

- in the seam parting "n11-n9" the decrease from ~60÷15% to ~5÷2%.

These changes do not apply to colostranova, approximately twenty-meter zone in which conditions the state of rock massif of mitoplast very similar to those in zone "C"above.

Made by "ΔΘ-factor" analysis of the state and variability of the rock mass in the process of nudebody allows to estimate the state of a rock mass narabotano thickness obtained on the basis mainly of the analysis fields εxand εy" in the same zones mitoplast. Using the relationship can be used in the form of a program product for collecting baseline data and developing methodological aspects of building degassing schemes for narabotano layer of the Fourth array of rocks taking into account spatial and temporal variability of its reservoir properties. Possible scheme of drilling degasification wells (conditions for the considered example) is shown in Fig.6.

The application of this method of developing a Suite of contiguous vysokogazonosnyh coal seams provides the following benefits:

- improving the efficiency of removal of methane;

- increase the load on the longwall face on the gas the WMD factor;

- improving the safety of doing cleaning work gas factor;

- reducing the cost of coal.

Method development Suite contiguous vysokogazonosnyh coal seams, including the determination of the length of the active zone of outgassing, the preparation of the mining of pillars by holding and fastening the conveyor and ventilation openings in the rock mass, the development of the mining of pillars, removing methane degasification wells, characterized in that the length of the active zone of the gas is determined by the change in volumetric strain ΔΘ of rock mass using dependencies:
ΔΘ=Θ0i,
where Θ0volumetric deformation of the rock mass prior to the longwall pillars; Θivolumetric deformation of the rock mass at the i-th stage of a longwall pillars,
the strain values Θ0and Θirocks get numerical methods based on the analysis of the components of the tensor of deformations and stresses taking into account the time factor, and the tensor characteristic is the permeability of rocks in the natural conditions of their occurrence, and to estimate the average values of the permeability kcfrocks use the expression:
kwith athe =k0with ap+aσwith ap;
wherek0with ap- average values of gas permeability of a rock mass in the presence of the rock mass conditions σcf→0; σcf- the average operating voltage working in the rock mass, kg/cm2; a is an empirical coefficient,
after determining the length of the active zone of the gas taking into account the received data select circuits drilling, the diameter and number.



 

Same patents:

FIELD: mining.

SUBSTANCE: for realisation of the method, drainage-degassing wells are drilled in zones of higher cracking outside the limits of the prepared mine. Wells are drilled in the bottom-up direction in the close proximity to the profile of the prepared mine. Pumping of gas saturated drainage brines is carried out until the level of the depression curve is set below the horizon of breaking works, and it is maintained at this level for the entire period of mining. Besides, in process of wells drilling the minimum permissible distance to the profile of the prepared mine is accepted as 0.035 m per each running metre of the well.

EFFECT: method makes it possible to increase safety of underground mining works due to reduce amount of arriving fuel gas and natural waters to mines from deep and deposit-adjacent horizons of earth interior.

2 cl, 2 dwg

FIELD: mining.

SUBSTANCE: method to degas coal-bearing series includes construction of a drainage mine along an extraction pillar in the coal-bearing guiding bed at the distance from the mined bed before start of construction of developing entries on the protected bed, using it as a degassing pipeline, which is ventilated separately. At the same time the drainage mine is constructed along the geometrically upper guiding bed in the area limited with fracture lines directed at the side of the protected bed, and it is ventilated due to depression pulled by the fan of local ventilation. Besides, jointly with construction of drainage mains the lower guiding bed is mined, which lies at the distance of not more than S along the normal line from the mined bed, determined by the given mathematical expression. Afterwards the coal bed is mined.

EFFECT: increased extent of methane extraction and reduced duration of degassing.

5 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: after the first treatment of the bed by gas generator each next cycle of its hydro-breakdown is done simultaneously with high-energy impulse action of set amplitude and duration with the help of gas generator that is descended with geo-physical cable into bed interval before the beginning of hydro-breakdown and is switched on at reaching certain parameters of hydro-breakdown - pressure, pumping speed, volume of pumped fluid. Note that each cycle of treatment is finished by sudden pressure drop in the well to hydrostatic one after extraction of geophysical cable and unburned remnants of gas generator to the surface.

EFFECT: increase of permeability and gas recovery of methane-containing outburst-prone coal beds, reduction and uniform distribution of stresses in them, intensification of coal production.

4 dwg

FIELD: mining.

SUBSTANCE: method includes drilling of degassing wells in a processed massif perpendicularly to direction of breaking face movement, performance of hydraulic ruptures of a coal bed from them and subsequent gas pumping. At the same time degassing wells are drilled as through with the lower mine to the upper one, and hydraulic ruptures are carried out by movement of a drilling rod in a reverse direction.

EFFECT: increased area of gas release and reduced time of degassing works.

3 dwg

FIELD: mining.

SUBSTANCE: method includes fluid supply through the well into the bed via delivery pump, fluid hydro-pulse impact on the bed, reduction of fluid well-head pressure to atmospheric pressure with its following discharge from the well. Together with fluid hydro-pulse impact on the bed there accumulated is the hydraulic energy of the stream, created by delivery pump, in hydraulic accumulator with the following supply of accumulated fluid into the well and with regular repeating of modes of fluid discharging from the well and its delivery into the bed. When fluid is pumped into the bed, well-head pressure is increased as quickly as possible and it is maintained via accumulated fluid supply for the time necessary for bed cracks formation. Then well-head pressure is decreased as quickly as possible to atmospheric pressure and fluid is discharged from the well. The sizes and configuration of cracks formed are defined by value and duration of applied pressure.

EFFECT: increase of coal bed degassing efficiency, reduction of labour costs.

FIELD: mining.

SUBSTANCE: method involves drilling of through holes in coal massif from outpost workings parallel to working face; cutting of initiating slots on walls of the above holes, their sealing and formation of coal hydraulic fracturing cracks by supplying the fluid to them. Besides, cutting of the next initiating slot is performed simultaneously with sealing of the previous initiating slot and by formation in it of coal hydraulic fracturing crack. Cutting of initiating slots in each subsequent hole is performed with a shift of cutting pitch relative to initiating slots of each preceding hole.

EFFECT: enlarging the area of uncovering of fractured coal massif.

3 dwg

FIELD: mining.

SUBSTANCE: method involves drilling of degassing holes in the developed massif from lower gate to upper gate, performance of hydraulic fractures from them by moving the drilling rod in backward direction and further gas pumping-out. One hole is drilled perpendicular to working face movement direction, the other one is drilled at an angle to the first hole, which is determined separately for each coal bed, and opposite the working face from lower part of lower gate to upper part of upper gate, the third one - at some angle to the first hole and in the working face movement direction from lower part of upper gate to upper part of lower gate.

EFFECT: enlarging gas emission surface area.

2 dwg

FIELD: mining.

SUBSTANCE: method involves driving in extraction pillar of conveyor, ventilation and intermediate gates, supply of fresh air to the face via ventilation and intermediate gates, drilling of degassing holes at the interval of 20÷25 m as to the bed rise, that is 5÷10 m before ventilation gate, and as to the bed dip with the hole outlet to the board of conveyor gate; drying of the bed by free efflux of formation water through holes to intermediate and conveyor gates. After the bed is dried, cement plugs are installed in the holes entering the board of conveyor gate, interval hydraulic factures of the bed are performed in degassing holes with the distance between hydraulic fracture cracks of 10÷15 m.

EFFECT: intensification of methane filtration rate is provided.

1 dwg

FIELD: mining.

SUBSTANCE: method includes installation of gas discharge pipes along general shaft ventilation lines and suction of methane from an insulated grinding chamber. Large coal blocks are ground in a grinding chamber upon their delivery there from lava. When coal blocks are damaged, the main quantity of methane contained in them is released and accumulated in a gas-accumulating cavity of a grinding chamber. From this cavity methane is sucked along a gas discharge pipeline to the surface for recycling. The grinding chamber is installed outside the borders of movement of a fresh air jet sent to ventilate second working.

EFFECT: higher efficiency of a developed bed by methane.

2 cl, 10 dwg

FIELD: mining.

SUBSTANCE: method consists in guiding the deviated horizontal/vertically horizontal wells from the ground surface with output of their downhole part to horizontal plane, provision the wells with pipe casing, connection to the vacuum pump and methane recovery from unworked coal. On the mine field a series of above-ground wells are guided with output of their horizontal portions into the working and superimposed coal seams. In addition to the above-ground wells, the short isolated from mine weather underground wells are designed and equipped, by means of those the hydraulic connection between above-ground well and underground ones is made with the capability of borehole fluid discharge. In preparation of excavation site for upwall development, the horizontal portion of above-ground well is guided along the axis of excavation site, and in preparation of excavation site for along-strike development - arriswise the lengthwise extended section of degassed reservoir, with minus angle of elevation of horizontal well portion. In the expanded excavation site a counter on-shore well is guided with placing its horizontal portion in the tapped coal seam.

EFFECT: gain in performance of gas drainage from the working and superimposed seams.

4 cl, 2 dwg

FIELD: mining.

SUBSTANCE: method of layer mining of thick flat coal beds includes separation of a bed into layers, separation of layers into mineral columns, mining of layers with long working faces in descending order, leaving a layer-to-layer pack, with arrangement of developing ventilation and travelling roadways of the upper layer, leaving column-to-column pillars. Preparation of the mined layer of the extracted bed is carried out in pair mines, namely, with an area ventilation mine and an unloading mine near the ventilation one, an area conveyor mine and an unloading mine near the conveyor one, and unloading mines are tunnelled without supporting, outstripping the area mines, at the same time the distance between pair mines and the value of bottomholes outstripping of the unloading mines above bottomholes of area mines is determined according to formulas.

EFFECT: increased stability and manufacturability of mines arrangement in a mined layer, reduced losses of minerals when mining lower layers.

2 dwg

FIELD: mining.

SUBSTANCE: method includes development of beds with longwalls along the strike using mechanised complexes. For this purpose during development of each underlying bed a longwall is arranged so that the remaining coal sight pillars near ventilation and conveyor drifts of the overlying bed are above the middle part of the extraction column, and extraction of coal beds is carried out in descending order.

EFFECT: higher safety of development of contiguous beds and lower labour inputs for roof management.

2 dwg

FIELD: mining.

SUBSTANCE: between sub-levels and compensating gates dividing sub-levels into mining blocks there are furnaces with slope parallel to angle of formation of caved ground in mined area relatively to the line of bed course. Ventilation roadway for ventilating the below sub-level is made after mining and forced falling of the roof at above sub-level, note that above the ventilation roadway there maintained is a protective pillar that temporary prevents rock falling. In below sub-level the roof is controlled by stepped bypassing of caved ground from the above sub-level to bottom-hole area of below sub-level, exposed for allowable passage, note that allowable passage of roof exposure in bottom-hole area of below sub-level and corresponding extended distance between the blocks in comparison to the above sub-level is defined by the expression.

EFFECT: invention allows increasing coal production efficiency.

3 cl, 9 dwg

FIELD: mining.

SUBSTANCE: method includes simultaneous coal extraction at upper and lower seams with advancing the broken working at upper seam and coal transportation to skip shaft from all longwall faces of worked-out seams of series. Penetration of vertical transportation blind pits from grouped field haul roadway to conveyor cross-cuts of all longwall faces is done at series travelling side. At series ventilation side there are vertical ventilation blind pits from grouped field ventilation roadway to ventilation cross-cuts of all longwall faces creating pyramid-shaped network of mines connected between themselves from lower to upper seam. The descending air stream from all series longwall faces is directed to ventilation bore through grouped field ventilation roadway made in the roof of upper seam. With the help of bulkheads with holes mounted in pyramid-shape network of mines there provided is a diagonal movement of air streams in the pyramid with exhaust of methane-air mixture from outgoing longwall faces and mines areas and formation of general mine ventilation air stream for extracting methane to the mine surface.

EFFECT: invention allows improving the efficiency of methane-air mixture exhaust from mine.

5 dwg

FIELD: mining.

SUBSTANCE: method consists in mining of the deposit with wells, creation of a cavity, and destruction and change-over of mineral product to hydraulic mixture. Mixture is mixed and hollow rock is deposited at the bottom of the formed cavity; coal-water suspension is pumped out to the surface and transported via pipes to the consumer. In order to destruct mineral product, high methane content of coal beds is used; at that, methane content in the formed cavity is controlled; and when the most explosion hazardous concentration of methane, which is equal to 10%, is achieved in that cavity, explosion is initiated. After mineral product is delivered to the consumer, the whole cycle of works is repeated. In order to prevent methane ignition, its concentration is reduced to explosion hazardous one by releasing methane via wells to the surface to consumers.

EFFECT: invention allows increasing the safety and efficiency of mine works owing to using internal energy of mine rock massif.

FIELD: mining.

SUBSTANCE: underground development method of the Elginsky coal deposit involves separation of the deposit into upper and lower formations, performance of paired tunnels and paired inclined working-outs, use of one branch of inclined working-outs and tunnels for coal transportation from loading points to coal-preparation plant, development of the deposit using an underground method sequentially in downstream order. Paired tunnels are performed on the lowest formation H2 of the northern deposit part to geological breakdown; cross galleries are made after geological breakdown out of tunnels transversely to the formation spread of the south-eastern part; those formations are opened with inclined shafts and worked out with a storeyed development system with coal transportation via inclined winzes and slopes to cross galleries, and then tunnels.

EFFECT: invention allows ensuring the efficiency of development of the south-eastern part of the deposit, complete extraction of coal and possibility of applying that method at any stage of the deposit development.

2 dwg

FIELD: mining.

SUBSTANCE: before the face enters the formation roof, wells are drilled towards each other on the side of extraction gates, in pairs as to formation and parallel to the support line at the distance from the well projection to the bottom of formation to the nearest point of removal chamber, which is equal to 0.7-0.8 of periodic step of convergence of the main roof; they are charged and blasted after the support line, by means of which a support is created on the side of worked-out space for a hanging plate of the main roof throughout the length of face by using the roof rocks fallen during blasting operations. Coal pillar arranged between mechanised support and removal chamber is provided with artificial flexibility and extracted under protection of the plate of the main roof, which is borne against the rocks fallen during the well blasting operations. The specified artificial flexibility is provided for the pillar by drilling from removal chamber of wells at the formation roof towards the face.

EFFECT: considerable improvement of safe operations at entry of the complex into removal chamber in wide range of conditions of coal beds occurrence.

2 cl, 3 dwg

FIELD: mining.

SUBSTANCE: as face advances from special chambers passed above preparatory minings on the side of extraction galleries there drilled opposite each other are wells parallel to formation at the distance from lower plane of the main roof to wells, which is determined by the following formula: Lllr=l3(1+√Kl) / (Kl -1), where Kl - rock loosening coefficient of the main roof at their blasting with loosening; l3 - distance from the main roof to fallen rocks, m; lllr - line of least resistance of blasting cone, m. Then, they are charged and blasted after the support line in the worked-out space. At each explosion there created is support from roof rocks fallen out of funnels throughout the face length, by means of which free falling of main roof, which is torn by explosion, is prevented.

EFFECT: considerable increase in mining of gas-bearing formations by means of mechanised complexes in wide range of coal bed in bedding zone of coal formations.

4 dwg

FIELD: mining.

SUBSTANCE: method includes preparation of a mine field by arrangement of transport and ventilation mines, alternate arrangement of mine chambers from a transport to a ventilation mine with anchor fixation of a roof, suppression of chamber-to-chamber pillars by coal mining with a frontal type combine and transportation of broken coal within the mine chamber. Adjacent chamber-to-chamber pillars are suppressed simultaneously with straight bottoms with a lag of the straight bottom of the chamber-to-chamber pillar arranged at the side of the non-mined coal massif from the straight bottom of the chamber-to-chamber pillar arranged at the side of collapsed rocks, by the value not exceeding 10÷12 m, and formation of a ventilation department by the mined part of the chamber of the ventilation compartment located between straight bottoms of the specified pillars.

EFFECT: higher efficiency of mining due to reduced coal losses by means of total mining of chamber-to-chamber pillars with provision of works safety.

3 cl, 3 dwg

FIELD: mining.

SUBSTANCE: method to manage a hard-to-collapse roof includes drilling of long and short inclined wells from preparatory mines into roof rocks, their charging and explosion with the help of explosives beyond a reinforcement line in a mined space. During each explosion of charges a support is arranged in long wells for a board of hard-to-collapse layers separated from the massif from rocks that fall out of the blasting cone along the entire length of the mining face. When exploding charges in short wells, supports are arranged near mine sections, and using established supports, free collapse of the main roof board portion that breaks off the massif during explosion is prevented, as well as pushing out of gas accumulated in the mined space into the bottomhole space of the long face.

EFFECT: increased safety of gas bearing beds mining.

3 dwg

FIELD: mining industry.

SUBSTANCE: method includes driving of layer transporting and ventilation mines along soil and ceiling of bed, in massive and in extracted space, cutting of cleaning mines in cross-section of bed at angle of 27°, mechanized delivery of coal along bed mines to coal furnaces and vertical dropping of coal to furnaces. Extraction of slanted transverse bed is performed along bed diagonals having direction to horizon at angle of 27°, to provide for free sliding of coal without degradation. Delivery of coal from cleaning mine placed at angle of 60° to layer mine, to back field mine is performed by self-delivery from any place of extraction field along layer mine, field coal-lowering mine and field slanting coal furnace, being at angle of 27° to horizon. Field slanted coal furnaces are placed at distance from one another along 20 m normal. Field coal mines in form of fans of three mines are connected on field slanted coal furnaces at distance of fan start from one another of 60 m with output of mines ends to each layer mine of group of three above-lying slanted-transverse layers for whole diagonal length of extraction field at distance between mines outputs along layer soil of 60 m. Ceiling of cleaning mines may be supported without load, utilizing mechanical traction on the side of ventilation furnaces for pressing moveable support tool to layer ceiling.

EFFECT: higher efficiency.

2 cl, 3 dwg

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