Unsealing of deposit

UNSEALING OF DEPOSIT (EN: deposit opening, deposit stripping; DE: Aufschluß des Lagers; FR: decoupage du gisement; ES: destape de yacimiento; RU: вскрытие месторождения) is the conducting of the mine workings (trenches, underground mine shafts, drilled boreholes, and others), which are opening the access from the surface to the depositions of the useful minerals within the Earth's bowels. Depending on the method for the development, which is being adopted, they distinguish the open-pit mine type, underground mine type, and borehole type unsealing of the deposit.

The open-pit mine type unsealing of the deposit is performed with the help of the capital trenches and half-trenches (inclined and steep), and of the cutting trenches (horizontal), less often using the underground mine workings (ore passes, adits, mine shafts, and inclined tunnels). In the individual cases, they perform the trenchless unsealing of the deposit (with the help of the tower excavators and cable cranes, and also with the help of the suction dredgers). The trenches are used for the unsealing of the deposits within the flat terrain, while the half-trenches are used within the hilly terrain. Depending on the position of the unsealing mine working relatively to the contour of the open-pit mine field, on the quantity of the serviced horizons, on the purpose and stationarity, they perform the unsealing using the capital trenches (half-trenches) with the external or internal embedment, individual, grouped or shared, single or paired, stationary or sliding.

(Figure # 1, b) The unsealing of the open-pit mine field, using the internal trenches

The unsealing of the deposit using the external trenches (see the Figure # 1, a) and half-trenches, which are situated outside the contour of the open-pit mine field, is limited to two or three horizons, because the quantity of the mining-construction works for the conducting of these trenches is added to the quantity of the mining works, which are performed within the open-pit mine field. The works for the conducting of the internal trenches (see the Figure # 1, b), which are situated inside the open-pit mine field, constitute the part of the total quantity of the mining works; the expenditures for the mining-construction works are decreased. However, their usage complicates the route, and leads to the certain increasing of the expenditures for the transportation of the mining mass during the process of the operation of the open-pit mine.

(Figure # 1, a) The unsealing of the open-pit mine field, using the external trenches

The unsealing of the deposit using the individual trenches, when each bench is unsealed using the independent trench, is used in case of the high productive capacity of the open-pit mine, as a rule, at the horizontal and flat depositions of the useful minerals. Such unsealing simplifies the transport approaches, distributes the freight flows, and assists to the decreasing of the expenditures for the transportation of the rock. The disadvantage of this method for the unsealing of the deposit is the significant quantity of the mining-capital works. In case of the unsealing of the deposit using the shared trenches (see the Figure # 1, v) or half-trenches, the freight-transport communication of all the stopes with the places for the reception of the mining mass on the surface is performed through one trench. The major advantage of this type of the unsealing of the deposit is the relatively small quantity of the work for the conducting of the mine working for the unsealing (in comparison with the unsealing of the deposit using the individual trenches), especially in case of the great depth of the zone, which is being unsealed, and in case of the significant quantity of the horizons, which are being unsealed; the disadvantage is the increasing of the complexity of the scheme for the transport communications, and the associated increasing of the operating expenditures for the transport.(Figure # 1, g) The unsealing of the open-pit mine field, using the grouped trenches(Figure # 1, v) The unsealing of the open-pit mine field, using the shared trenches

The unsealing of the deposit using the grouped trenches (see the Figure # 1, g) is performed in case of the necessity for the separation of the freight flows. In this case, each trench services the group of the horizons. The unsealing of the deposit using this method is most effective in case of the existence of the zones of the open-pit mine field, which are different according to their natural properties; according to the advantages and disadvantages, this method holds the intermediate place between the unsealing of the deposit using the individual and shared trenches. In case of the unsealing of the deposit using the paired trenches (see the Figure # 1, d) for the creation of the streaming movement of the transport, they unseal the group of the benches or all the benches, using the two (unlike the unsealing of the deposit using the single trenches, within which the movement of the transport is performed along both directions) trenches of the external or internal emplacement. In this case, the empty and loaded transport is divided for the directions, and there is performed the streaming delivery of this transport for the loading.

(Figure # 1, d) The unsealing of the open-pit mine field, using the paired trenches(Figure # 1, e) The unsealing of the open-pit mine field, using the steep trenchThey categorize as stationary the trenches, which are positioned outside the contour of the open-pit mine, or on the non-working edge of the open-pit mine. The sliding trenches, which are often used for the unsealing of the deposit with the steep depositions, are positioned within the working zone of the open-pit mine, and, with the advancement of the mining works, they move towards the limiting contour of the open-pit mine. Here, during the mining of the corresponding horizon, these trenches transition into the continuation of the stationary trench. The unsealing of the horizons using the sliding trenches is most widespread in case of the automotive transport; this unsealing is performed with the minimal expenditures of the time.

Depending on the configuration of the open-pit mine field in terms of the projection onto the horizontal plane, on its depth, on the productive capacity, and on the type of the transport, which is being used, the route, which is unsealing the open-pit mine field of the mine workings, may be simple (does not change its direction on the edge of the open-pit mine), and may be complicated, namely, of the dead-end type (the change of the direction for the movement of the transport is performed at the dead-end places), of the loop type (the change of the direction for the movement of the mostly automotive transport is performed using the loop turns at the places), of the spiral type (passes along all the edges of the open-pit mine in the form of the spiral, which is entwining the contour of the deposition), or combined (the combination of the spiral route with the route of the dead-end type or of the loop type). The route of the unsealing mine workings in terms of the profile comprises the inclined places, which are connecting the horizons; the points of the junction of the working horizons to the route; the conjugating curves. In terms of the projection onto the horizontal plane, the elements of the route are the roundings, dead ends, stations, and passing places. The inclination of the inclined places of the route is determined according to the parameters of the transport, which is being used, the necessary throughput ability of the trench, the mode and organization of the movement of the transport units, and so on.

The junction of the working horizons to the route of the unsealing mine working is performed at the horizontal places, and also at the places with the governing or softened (less than governing) upward inclination. Using the points of the junction, the entire route is usually divided into the road segments. The parameters (the quantity of the paths or lanes for the movement, the inclination, the structure of the basis) of the most freight-intensive road segment (of the so-called limiting road segment) are adopted as the source parameters for the determination of the parameters for the capital trench.

Using the steep trenches (see the Figure # 1, e), which are being situated on the edge, which does not work permanently or temporarily, there is performed the unsealing of the deep horizons within the open-pit mine fields in case of the combined transport. The depth of the emplacement of the trenches is determined according to the place of the situation of the place for the transloading from the stope transport onto the lifting transport. (Figure # 2) The unsealing of the open-pit mine field with the usage of the ore chutes

They also use the steep trenches (ore chutes) for the unsealing of the deposits with the oblique mountainous relief of the surface (see the Figure # 2).

In this case, the trenches are situated outside the open-pit mine field, and are purposed for the descent (gravitational transportation) of the mining mass. The route of the ore chute, while taking into account the acceptable angle of the inclination of the basis, is chosen according to the condition of the minimal distance between the open-pit mine and the place for the reception of the freight. In case of the small inclinations and low intensity of the freight flow, there is constructed the accumulating bunker within the bottom part of the ore chute, while in case of the significant inclinations and high intensity of the freight flow, there are constructed the accumulating places.

During the unsealing of the deposit, the cutting trenches and half-trenches are conducted with the purpose of the preparation of the horizon for the operation. In the general case, the place for the emplacement of the cutting trench is determined on the basis of the analysis of the regime of the mining works. At the horizontal tabular depositions, they penetrate the cutting trenches, while taking into account the direction and speed of the advancing of the front of the works. At the flat and tabular depositions, they situate these trenches at the side of the footwall of the deposition, near the boundaries of the outcrop of the layer under the alluvia; during the unsealing of the inclined and steep tabular depositions with the small and medium thickness, they situate these trenches through the contact of the layer at the side of the hanging wall of the deposition, while at the thick depositions, they situate these trenches through the useful minerals near the contact of the footwal l of the deposition.

The mutual coordination of the places for the emplacements of the cutting and capital trenches during the unsealing of the deposit is performed, while taking into account the specificity, which is inherent to each of these mine workings. In case of the parallel advancing of the front of the works, large length of the cutting trench, and placement of the rocks of the overburden into the goaf space, they often unseal the horizontal deposits using the external paired capital trenches; under the same conditions, in case of the short front of the works (for the decreasing of the expenditures for the mining-capital works), they unseal such deposits using the external shared capital trench for the wheeled transport, and using the internal trench for the conveyor transport. At the same time, for the simplification of the configuration of the route within the projection onto the horizontal plane, they strive as possible to situate the external trenches at the right angle to the cutting tre nch. Analogously, there are unsealed the flat deposits. In case of the significant length of the open-pit mine field, for the transportation of the useful minerals, they perform the central emplacement of the capital trench, while for the transportation of the overburden rocks, they perform the flanked emplacement of the capital trench. In case of the fan-shaped advancing of the front of the works (the transportation of the overburden rocks into the goaf space using the railway transport), they perform the unsealing of the deposit using the external capital trench with the viaduct for the transportation of the overburden rocks. The unsealing of the inclined and steep tabular deposits is usually performed using the system of the external capital trenches and internal tranches. They unseal the steep ore depositions, as a rule, using the internal trenches, while taking into account the effectiveness of the mining of the deposit using the stages according to the depth. In this case, the duration of the service of the capital tranches is limited by the time of the mining of each stage. In case of the unsealing of the ore deposits, the place of the situation of the cutting trenches is determined by the situation of the route within the contours, which are corresponding to the current stage of the development. In case of the spiral-shaped route (is used most often) the cutting trench at each horizon is situated along the limiting contour, with the fan-shaped advancing of the front of the works at each horizon, which is being unsealed, around the place of the junction of the internal capital trench with the cutting trench.(Figure # 3) The unsealing of the open-pit mine field, using the trench-canal

In case of the hydraulic mechanization, the usage of the means for the unsealing of the deposit exerts the significant influence onto the character of the unsealing of the deposit using the open-pit mine. In this case, they conduct the mine workings, which are not only opening the access to the depositions of the useful minerals, but which are also creating the water area for the work of the floating dredgers, or which are ensuring the usage of the equipment for the suction of the earth. Depending on the type of the unsealing mine workings, in case of the usage of the floating dredgers, they distinguish the following methods for the unsealing of the deposit: using the pioneer pit, using the trench-canal, using the water flooding of the surface of the deposit, and using the method without any trench. In case of the unsealing of the deposit using the pioneer pit (the most distributed method for the unsealing of the deposits), the mine working is being penetrated mostly in the form of the sector within the limits of the open-pit mine field, and, after the digging, is filled with the ground waters. The depth of the initial pit relatively to the level of the ground waters is determined depending on the water-performance of the dredger for the suction of the earth. The volume of the pit is usually several thousands cubic metres. The unsealing of the deposit using the trenc h-canal, which is conducted along the contour of the deposit, is performed, as a rule, in case of the situation of the water source (river, lake) near the deposit (see the Figure # 3).

The width of the mine working at the bottom exceeds the 1/5 of the length of the dredger by 10 metres, while the depth of the water within the canal exceeds the depth of the draught of the dredger by 0.6-1 metres. In case of the unsealing of the deposit using the water flooding of the surface of the deposit, which is performed in case of its situation higher than the level of the waters within the water source, they perform the lifting of the water using the dams, other special built structures, and pumps. In the latter case, they preliminarily embank the space, which is filled with the water, using the special dams. The dimensions of this place must ensure the normal conditions for the butterfly-shaped sweeping using the suction dredger with the angle of the rotation of at least 60 degrees, and also must ensure the placement of at least three segments of the floating slurry pipeline.(Figure # 4, b) The unsealing of the mine field: the stratigraphic suites of the layers(Figure # 4, a) The schemes for the unsealing of the mine fields

The unsealing of the deposit without any trenches is used for the development of the deposits, which are situated within the limits of the water area of the water source (for example, within the channel of the river). Depending on the quantity of the horizons, which are being unsealed, the unsealing of the deposit is possible using the individual, grouped, and shared pits, and trenches-canals. These unsealing mine workings may be of the internal and external emplacement. The unsealing of one horizon may be performed using several pits, within each of which there works the dredger for the suction of the earth. In case of the unsealing of the deposit without any trenches, with the transportation of the slurry using the free gravitational flow, they conduct only the ditches for the reception of the slurry, which further transition into the troughs. The underground mine workings, where is situated the equipment for the hydraulic transportation, are used for the unsealing of the highland deposits and deeply embedded deposits.

In case of the unsealing of the underground mine field using the underground mine, they distinguish the unsealing using the vertical (see the Figure # 4) and inclined (see the Figure # 5) underground mine shafts.

They also perform the unsealing of the deposit using the combined method (see the Figure # 6), in case of which there are used together the mine workings of one and another type within the limits of one underground mine field.

In case of the complicated relief of the surface, at the mountains or on the very rough terrain, as a rule, they perform the unsealing of the deposit using the adits (see the Figure # 7), or they use the combined method (the adits in combination with the vertical or inclined underground mine shafts).

The most universal and distributed method for the unsealing of the deposit is using the vertical mine shafts, which may transverse the rocks and layers (depositions) of the useful minerals, or which may be located within their soil (within the footwall). They usually penetrate the inclined mine shafts (see the "Mining-capital works" article) through the layer, and less often through the country rocks; they penetrate the adits both through the layer, and through the rock within the footwall or hanging wall, along the strike, or across the strike of the layer (of the ore body). They construct the mine shafts at once throughout the complete depth, or to the determined horizon, with the subsequent deepening (see the "Mining-penetration works" article). In association with this fact, they distinguish the unsealing of the deposit with one or several transport horizons. In case of the unsealing of the deposit using the inclined mine shafts, there are practically possible only the multi-horizon methods, while in case of the usage of the adits, there are possible the single-horizon methods, and the combined methods.

They situate the major mine shaft for the issuance of the useful minerals from the underground mine in such manner, that this mine shaft would divide the underground mine field both along the dip, and along the strike, into the two approximately equal parts. The auxiliary vertical mine shafts (one or several), which are constructed for the creation of at least two individual exits onto the surface, for the issuance of the rock, for the descent (ascent) of the people, materials, and so on, may have the central, central-shifted, flanking, combined, and sectional situation in relation to the main mine shaft. In the first case, the auxiliary mine shaft is situated near to the main mine shaft. In case of the central-shifted situation, they penetrate the auxiliary mine shaft near the upper boundary of the underground mine field, while in case of the flanking situation, they penetrate the auxiliary mine shaft also near the upper boundary at the flanks; in case of the combined situation, besides the two (less often three) mine shafts, within the centre of the underground mine field, within each panel (within each panel group), they construct the additional ventilation mine shafts or exploratory pits near the upper boundary of the mine field.

In case of the sectional scheme, the main and auxiliary mine shafts are located at the centre of one of the blocks of the underground mine field, while within other blocks, they construct their own central or central-shifted mine shafts for the ventilation, which are allowing to ensure the direct-flow airing of the underground mine workings. The central mine shafts perform all the transport functions, and serve for the delivery of the fresh air into the underground mine (except the mine shaft with the skip hoist for the issuance of the useful minerals at the underground coal mines). They use the ventilation mine shafts for the diversion of the outgoing stream of the air from the underground mine and so on. At the deposits, which are represented by the stratigraphic suite of the layers or ore bodies, which are embedded together, they perform the unsealing of the deposit independently in relation to the individual layers of these layers, using the capital mine workings, or using the complexes of various types of these mine workings. In the latter case, the unsealing of the deposit is performed using the vertical mine shafts, and using the capital, level-wise, and horizon-wise crosscuts, adits, vertical mine shafts, and so on.

The single-horizon scheme for the unsealing of the stratigraphic suite with the flat layers using the vertical mine shafts and capital crosscut is used in case of the angle of the dip of the layers of 8-18 degrees, with the sizes of the underground mine field along the dip of at most 2.5 kilometres. This scheme is distinguished with the relatively large quantity of the inclined capital mine workings, which decreases the effectiveness of the production because of the usage of the little-performance rope haulage, and also because of the significant leakage of the air, which emerges during the movement of this air through the inclined mine workings along the opposite directions.

The multi-horizon unsealing of the flat layers using the vertical mine shafts and horizon-wise crosscuts is performed in case of the angles of the dip of the layers of 8-18 degrees, with the sizes of the underground mine field along the dip from 2.5 to 4 kilometres and more. This scheme requires the sequential deepening of the mine shafts, and the penetration of several parallel crosscuts (at one or several horizons). If the upper boundary of the underground mine field is located comparatively near to the Earth's surface, then, for the airing of the mine workings, they penetrate the exploratory pits within each panel of the first horizon, or they construct one flanking mine shaft near to the boundaries of the adjacent panels, and they construct the ventilation crosscut.(Figure # 5, a) The unsealing of the underground mine field, using the inclined mine shafts, which have been penetrated through the deposition of the useful mineral

In case of the division of the underground mine field into the blocks, the unsealing of the deposit of the stratigraphic suites of the gas-bearing layers is performed using two or three mine shafts within the middle part of the central block, from which they conduct into both sides one or two haulage drifts of the field type, which are connected among them, in their turn, using the crosscuts, which are constructed within each block. Within the immediate vicinity of the crosscuts within the block, they penetrate the air-delivering mine shaft for the block, while near the upper boundary of the block (within its middle part, or at the flanks), they penetrate the air-issuing mine shafts. Such method for the unsealing of the deposit ensures the separate airing for the mine workings within the blocks, creates within the limits of these blocks the conditions for the concentration of the freight flows, and for the complete conversion of the transport into the transport of the conveyor typ e. The useful minerals are delivered within the heavy-freight minecarts using the electric locomotives of the heavy type through the lateral crosscuts and main drift to the mine shafts.

They unseal the very flat and horizontal layers using the vertical mine shafts, with the simultaneous penetration of the crosscuts, inclined winzes, and slopes through the rock, and with the division of the underground mine field into the blocks; they unseal the steep layers using the vertical mine shafts with the crosscuts within the levels. In case of this method for the unsealing of the deposit, the transportation of the useful minerals is performed within the minecarts from the clearing stopes through the horizontal mine workings to the hoppers near the mine shaft, and then onto the surface using the skip hoist. In this case, they air the mine workings, as a rule, according to the central scheme of the return flow type, and less often according to the diagonal scheme with the usage of the flanking mine shafts for the ventilation.

(Figure # 5, b) The unsealing of the underground mine field, using the inclined mine shafts, which have been penetrated through the rocks within the hanging wall

At the working underground mines, the unsealing of the new horizons is performed using the method of the penetration (deepening) of the mine shafts, slopes, crosscuts, winzes, and mine workings of the pit bottoms. In this case, according to the type of the mine working, which is used for the issuance of the rock of the new horizon, and according to the quantity of the horizons, which are being unsealed simultaneously, there are distinguished three major groups of the unsealing: using the slopes, using the deepening of the mine shafts, which have been penetrated earlier (see the Figure # 8), or using the penetration of the new mine shafts to the horizon, which is being prepared, or to the level below this horizon, and using the dual levels.

In the series of the cases, they perform the unsealing of the steeply dipping ore bodies, using the vertical mine shafts with the horizons for the concentration. According to this scheme, per each 2-4 levels, they construct one major horizon for the concentration, and 1-3 intermediate horizons (see the Figure # 9).

On the horizon for the concentration, there is constructed the entire complex of the mine workings of the pit bottom, with the crushing installation and crosscuts, while on the intermediate horizons, there are constructed only the auxiliary crosscuts for the delivery of the air, and for the delivery of the people and materials. The ore is delivered through the crosscuts of the intermediate horizon only to the capital ore pass, which has been penetrated into the horizon for the concentration within the region of the ore body.

(Figure # 5, v) The unsealing of the underground mine field, using the inclined mine shafts, which have been penetrated through the rocks of the hanging wall and footwall

At the greater depths, they unseal the ore depositions according to the two-stage scheme, in case of which they penetrate the vertical mine shafts to the depth of 1500-1800 metres, and yet deeper they construct the concealed vertical or inclined mine shafts (see the Figure # 10).

They perform the unsealing of several isolated ore bodies within the place with the relatively small area together according to the grouped scheme, in case of which they bypass the useful minerals from the upper levels of the individual ore bodies to the unified horizon for the concentration, and they deliver these useful minerals to the shared mine shaft for the lifting of the ore. Within the mountainous terrain, they often perform the unsealing of the ore bodies using the trenches within the highland part, which is processed later using the open-pit mine, and, in case of the underground development, also using the adits, mine shafts, and capital ore passes. They unseal the ore body below the adit horizon, using the concealed mine shafts. The adit horizon is the major transport horizon; they penetrate the auxiliary mine shafts for the ventilation, and for the descent-ascent of the people and loads.

The major peculiarity of the unsealing of the deposit in case of the underground hydraulic extraction includes the significant decreasing of the volume of the unsealing (and preparatory) mine workings, because the usage of the hydraulic transport and hidraulic lifting imposes the limitations onto the cross-section of the mine workings only according to the norms of the ventilation. They unseal the underground mine fields of the underground hydraulic mines, using the inclined mine shafts, which have been penetrated through the coal layers (as a rule, the shallow horizons), using the vertical mine shafts with the crosscuts and without them, and using together the inclined and vertical mine shafts.

(Figure # 5, g) The unsealing of the underground mine field, using the inclined mine shafts, which have been penetrated in combination with the crosscuts and inclined mine working

The unsealing of the deposit of the stratigraphic suite with the flat and inclined layers at the hydraulic mine is performed using the vertical mine shafts without the capital crosscuts. On each layer, which is being unsealed, there is performed the cross-cutting of the mine workings near the mine shaft (the receiving places for the auxiliary lift). On the lower layer of the group of the layers, there is constructed near the mine shaft the station for the hydraulic lifting. This method for the unsealing of the deposit, which has been specified, may be combined with the scheme, which includes the conducting of the crosscuts. Such combination of the methods for the unsealing of the deposit is used, when there is embedded within the limits of the underground mine field the group of the inclined layers along with the groups of the adjacent layers. The stratigraphic suites of the inclined layers may be unsealed using the central-dual mine shafts with the crosscuts of the block type. Th ey penetrate the mine shafts to the lower layer, where is constructed the pit bottom. The conduct two drifts of the field type from this pit bottom, and at the certain distance from these drifts, they conduct the crosscuts of the block type with the increased inclination (0.08) for the hydraulic transport. For the ventilation, near the upper boundary of the underground mine field, there are penetrated the crosscut for the ventilation, and the exploratory pit for the ventilation. In case of this scheme for the unsealing of the deposit (and for the preparation), there is simplified the transportation of the hydraulic mixture and auxiliary materials; there are decreased the total expenditures for the maintenance, because the mine workings with the prolonged duration of the service, which are conducted, are of the field type.

The unsealing of the deposit of the stratigraphic suite with the steep layers is also performed using the central-dual vertical mine shafts with the crosscuts of the block type. The layers are unsealed simultaneously. They penetrate the mine shafts within the rocks of the footwall. From the crosscuts of the level type towards the underground mine field along the strike, they conduct the grouped drifts for the accumulation on the lower horizon, and the grouped drifts for the haulage on the middle horizon. In case of the average length of the wing of the underground mine field of 2000-2500 metres, with the inclination of the grouped drifts for the accumulation of 0.05, the height of the level near the mine shaft amounts to 110-135 metres. The sizes of the underground mine field along the dip are determined according to the condition for the ensuring of 15-25 years for the duration of the service of the horizon.(Figure # 6, b) The scheme for the combined unsealing of the underground mine field(Figure # 6, a) The scheme for the combined unsealing of the underground mine field

The borehole type unsealing of the deposit includes the drilling and lining, the equipment of the bottomhole and mouth of the borehole, the equipping and mastering of the drilled boreholes for the subsequent extraction of the useful minerals. They use this unsealing at the reservoirs of the petroleum, of the natural gas, of the underground waters, and also of the solid useful minerals, which are subjected to the thermal (for example, gasification), chemical (leaching, dissolution), hydraulic, and hydromechanical (the hydraulic extraction of the borehole type) impact.

The situation and quantity of the boreholes at the deposit is determined according to the conditions of the most complete extraction of the useful minerals from the layer, and of the level of the capital expenditures for the development of the deposit. As a rule, they unseal the productive layers of the petroleum and gas reservoirs, using the boreholes throughout their entire thickness, with the subsequent lining using the casing string and insulation (using the plugging fluid) of all the petroleum, gas, and water-saturated layers, which have been unsealed. Later, they perform the secondary unsealing of the layers with the useful minerals, using the bullet-shaped, shaped-charge, or hydraulic sand-blasting perforators. They also unseal the reservoirs of the petroleum, using the multi-bottomhole boreholes.

(Figure # 7, a) The unsealing of the underground mine field, using the adits(Figure # 7, b) The unsealing of the underground mine field, using the aditsThe choice of the method for the unsealing of the layers of the useful minerals depends on the magnitude of the layer pressure. They unseal the layers with the abnormally high pressures, with the usage of the heavy drilling fluids with the high density; they unseal the layers with the pressures, which are near to the hydrostatic pressure, with the usage of the normal drilling fluids; and they unseal the layers with the pressures, which are less than the hydrostatic pressure, with the usage of the lightweight drilling fluids (aerated, on the hydrocarbon basis, foams), or with the usage of the blowing using the gaseous agents. They equip the mouth of the boreholes, which are being drilled, with the blowout preventer devices, for the prevention and elimination of the manifestations of the petroleum, gas, and water.

In case of the borehole type unsealing of the deposit of the solid useful minerals, they unseal the layers throughout the entire thickness, with the extraction of the core within their roof, productive part, and sole. Later, they deepen the borehole within the underlying rocks, for the placement of the extracting equipment (for example, in case of the borehole type hydraulic extraction of the useful minerals). They fixate the borehole using the casing string to the roof of the deposition (of the layer). They do not fixate using the casing string the layers of the useful minerals within the stable rocks, but they fixate the layers of the useful minerals, which are represented by the rocks, which are broken easily, using the mineral or polymeric plugging materials, and they also use various filters, which are limiting the inflow of the particles of the rock from the layer into the borehole. They lower the filters into the borehole, namely, they include these filters into the structure of the casing string, or they deposit these filters into the annulus (the gravel filters); they also use the combinations of these filters.

(Figure # 8) The scheme for the unsealing of the underground mine field, using the deepening of the mine shafts(Figure # 7, v) The unsealing of the underground mine field, using the aditsAfter the perforation of the casing string (or after the installation of the filter), and after the lowering of the pumping-compressor pipes into the borehole, they equip the mouth of the borehole with the special fittings, and they perform the works for the invocation of the inflow of the layer fluids. At the layers with the abnormally high pressures, they perform the invocation of the inflow within the boreholes, using the method of the replacement of the dense drilling fluid with the less dense drilling fluid or with the water. In case of the layer pressures, which are near to the hydrostatic pressure or are lesser than this pressure, they master the borehole, using the decreasing of the bottomhole pressure on the account of the aeration of the drilling fluid, on the account of the lowering of the level of the liquid within the borehole using the compressor method, and also with the help of the piston (swab) or bailer.

The adopted method for the unsealing of the deposit, in combination with the preparation and systems for the development, with the productive capacity and sizes of the open-pit mine (underground mine) field, and with the equipping and mastering of the drilled boreholes, must ensure the high technical level and reliability of the work of the enterprise, the possibility of the constructive adaptation of the network of the mine workings to the changing conditions of the construction, production, and environment, and also the possibility of the rapid performance of the works for the preparation of the new horizons, for the technical re-equipment, and for the reconstruction of the mining enterprise.

(Figure # 9) The unsealing of the steep ore deposition(Figure # 10) The scheme for the two-stage unsealing