MXPA01005013A - Method and system for accessing subterranean deposits from the surface - Google Patents

Abstract

Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.

Description

METHOD AND SYSTEM FOR ACCESSING UNDERGROUND DEPOSITS FROM THE SURFACE TECHNICAL FIELD OF THE INVENTION The present invention relates generally to the recovery of underground deposits, and more particularly to a method and system for accessing underground deposits from the surface.

BACKGROUND OF THE INVENTION Underground coal deposits contain substantial amounts of trapped methane gas, for many years, there has been a limited production of methane gas from coal deposits. Substantial obstacles, however, have thwarted the more exhaustive development of methane gas deposits in coal seams. The main problem in the production of coal seam methane gas is that although coal seams can extend over large areas up to several thousand acres, the coal seams are very shallow, varying from a few inches to several. meters Thus, although coal seams are often relatively close to the surface, vertical wells drilled in the Coal deposits to obtain methane gas can drain only a very small radius around the coal deposits. In addition, coal deposits are not sensitive to pressure fracture and other frequently used methods to increase methane gas production from rock formations. As a result, once the gas drained from a vertical borehole into a coal seam is easily produced, the additional production is of limited volume. Additionally, coal seams are often associated with groundwater, which must be drained from the coal seam to produce methane. Horizontal drilling patterns have been attempted to extend the amount of coal seams exposed to a gas extraction bore. Such horizontal drilling techniques, however, require the use of a radial borehole, which represents difficulties in removing the water trapped in the coal seam. The most efficient method for pumping water from an underground well, an extraction pump, does not work well on horizontal or radial drilling. An additional problem for the surface production of coal seam gas is the difficulty presented under the sub-balanced borehole conditions caused by the porosity of the seam. coal. During vertical and horizontal surface drilling operations, drilling fluid is used to remove cuts from the borehole to the surface. The drilling fluid exerts a hydrostatic pressure on the formation in which, if it exceeds the hydrostatic pressure of the formation, it can result in a loss of drilling fluid towards formation. This results in the entry of drilling fluids into the formation, which tends to clog pores, create cracks and fractures that are more necessary to produce gas. As a result of these difficulties in the surface production of methane gas from coal deposits, the methane gas that must be removed from the coal seam before mining has been removed from the coal seams through the use of underground methods. Although the use of underground methods allows water to be easily removed from the coal seam and eliminates sub-balanced drilling conditions, they may only have access to a limited amount of the coal seams exposed by current mining operations. Where mining is practiced on long walls, for example, drillers mounted on underground rails are used to drill horizontal holes from a panel that is currently being subjected to mining operations to an adjacent panel that will later be subjected to mining operations. The limitations of underground drills limit the reach of such horizontal holes and thus the area that can be effectively drained. further, the degassing of a next panel during the mining of a previous panel limits the degassing time. As a result, many horizontal holes must be drilled to remove the gas in a limited period of time. In addition, under conditions of high gas content or gas migration through a coal seam, it may be necessary to accelerate or delay mining until the next panel can be adequately degassed. These production delays are added to the expenses associated with the degassing of a coal seam.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides an improved method and system for accessing underground deposits from the surface that eliminate or substantially reduce the disadvantages and problems associated with the above systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a cavity well horizontal. The drainage patterns provide access to a large underground area from the surface while the vertical cavity well allows trapped water, hydrocarbons, and other deposits to be removed and / or efficiently produced. According to one embodiment of the present invention, a method for accessing an underground zone from the surface includes drilling a substantially vertical borehole from the surface to the underground zone. An articulated borehole is drilled from the surface to the underground zone. The articulated borehole is horizontally offset from the borehole substantially vertical on the surface, and intersects the substantially vertical borehole at a junction near the underground zone. A substantially horizontal drain pattern is drilled through the articulated borehole from the junction to the underground zone. According to another aspect of the present invention, the substantially horizontal drainage pattern may comprise an articulated pattern that includes a substantially horizontal diagonal borehole, extending from the substantially vertical borehole defining a first end of a covered area. by the drainage pattern until a distant end of the area. A first substantially horizontal lateral borehole extends in spatial relationship to another of the diagonal boreholes toward the periphery of the area on a first side of the diagonal borehole. A second set of substantially horizontal lateral boreholes extends in spatial relation to another of the diagonal boreholes toward the periphery of the area on a second side opposite the diagonal. According to yet another aspect of the present invention, a method for preparing an underground zone for mining uses substantially vertical and articulated boreholes and the drainage pattern. The water is drained from the underground zone through the drainage pattern to the junction of the substantially vertical borehole. The water is pumped from the junction to the surface through a substantially vertical borehole. The gas is produced from the underground zone through at least one of the substantially vertical and articulated boreholes. After degassing has been completed, the underground zone can also be prepared by pumping water and other additives into the area through the drainage pattern. According to yet another aspect of the present invention, there is provided a device for pump positioning to place exactly one pump at the bottom of the borehole in a borehole of a borehole. The technical advantages of the present invention include providing an improved method and system for accessing underground deposits from the surface. In particular, a horizontal drainage pattern is drilled in a target zone from an articulated surface well to provide access to the area from the surface. The drainage pattern intersected by a vertical cavity well from which trapped water, hydrocarbons and other fluids drained from the area can be removed and / or efficiently produced by an extraction pump unit. As a result, gas, oil and other fluids can be efficiently produced on the surface from a low pressure or low porosity formation. Another technical advantage of the present invention includes providing an improved method and system for drilling low pressure reservoirs. In particular, a pump placed at the bottom of the borehole or a gas lift is used to lighten the hydrostatic pressure exerted by the drilling fluids used to remove cuts during drilling operations. As a result, they can be perforated reservoirs at ultra-low pressures without loss of drilling fluids towards the formation and obturation of the formation. Yet another technical advantage of the present invention includes providing an improved horizontal drainage pattern to access an underground zone. In particular, an articulated structure with a main diagonal and opposite sides is used to maximize access to an underground zone from a single vertical borehole. The length of the sides is maximized near the vertical borehole and decreases toward the end of the main diagonal to provide uniform access to a quadrilateral area of another grid area. This allows the drainage pattern to be aligned with the side wall panels and other subsurface structures for the degassing of a coal seam or other deposit of a mine. Even another technical advantage of the present invention includes providing an improved method and system for preparing a coal seam or other underground deposit for mining operations. In particular, shallow wells are used to degas a coal seam before mining operations. This reduces equipment and activities underground and increases the time provided to degas the vein, which minimizes interruptions due to the high gas content. In addition, water and additives can be pumped into the degassed coal vein before mining operations to minimize the production of dust and other hazardous conditions, to improve the efficiency of the mining process, and to improve the quality of the mining process. product of coal. Even another technical advantage of the present invention includes providing an improved method and system for producing methane gas from a coal seam subjected to mining operations. In particular, the boreholes used to initially degas a coal seam prior to mining operations can be reused to collect gas from vein fill massifs after mining operations. As a result, the costs associated with the collection of gas from fill massifs are minimized to facilitate or make feasible the collection of gas from vein fill massifs previously subjected to mining operations. Still another technical advantage of the present invention includes providing a positioning device for automatically positioning pumps in the bottom of the drilling and other equipment in a cavity. In particular, a rotary cavity positioning device is configured to retract and transport in a borehole and to extend into a cavity in the bottom of the bore for optimal placement of the equipment within the cavity. This allows the equipment at the bottom of the hole to be easily positioned and secured within the cavity. Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like numerals represent similar parts, in which: Figure 1 is a cross-sectional diagram illustrating the formation of a horizontal drainage pattern in an underground zone through the articulated surface well intersecting the vertical cavity well according to an embodiment of the present invention; Figure 2 is a cross-sectional diagram illustrating the formation of a horizontal drainage pattern in an underground zone through the articulated surface well intersecting the vertical cavity well according to an embodiment of the present invention; Figure 3 is a cross-sectional diagram illustrating the production of fluids from a horizontal drainage pattern in an underground zone through a vertical borehole according to an embodiment of the present invention.; Figure 4 is a top plan diagram illustrating an articulated drainage pattern for accessing deposits in an underground zone according to an embodiment of the present invention; Figure 5 is a top plan diagram illustrating an articulated drainage pattern for accessing deposits in an underground zone according to another embodiment of the present invention; Figure 6 is a top plan diagram illustrating a quadrilateral articulated drainage pattern for accessing deposits in an underground zone according to yet another embodiment of the present invention; Figure 7 is a top plan diagram illustrating the alignment of drainage patterns articulated within panels of a coal seam to degas and prepare the coal seam for mining operations in accordance with one embodiment of the present invention; Figure 8 is a flow diagram illustrating a method for preparing a coal seam for mining operations in accordance with an embodiment of the present invention; Figures 9A-C are cross-sectional diagrams illustrating a positioning tool in the well of the cavity according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates a combination of an articulated well and cavity for accessing an underground zone from the surface in accordance with one embodiment of the present invention. In this mode, the underground zone is a coal vein. It will be understood that similar access to other low pressure, low pressure and low porosity underground zones can be accessed using the double well system of the present invention to remove and / or produce water, hydrocarbons and other fluids in the area and to treat minerals in the area before mining operations.

Referring to Figure 1, a substantially vertical borehole 12 extends from the surface 14 to a target coal vein 15. The substantially vertical borehole 12 intersects, penetrates and continues below the coal seam 15. The borehole 15 substantially vertical sounding is coated with a suitable well tubing 16 terminating at or above the level of the coal seam 15. The substantially vertical borehole 12 is recorded during or after drilling to locate the exact vertical depth of the coal seam 15. As a result, the coal seam is not lost in subsequent drilling operations and techniques are used to locate the seam 15 as long as it is not necessary to use the perforation. An elongated diameter cavity 20 is formed in the substantially vertical borehole 12 at the level of the coal seam 15. As described in more detail below, the elongated diameter cavity 20 provides a junction for the intersection of the borehole substantially vertical by the articulated borehole used to form a substantially horizontal drain pattern in the coal seam 15. The elongated diameter well 20 also provides a collection point for drained fluids from the coal seam 15 during production operations .

In one embodiment, the elongated diameter cavity 20 has a radius of approximately 2.4 m (8 feet) and a vertical dimension that equals or exceeds the vertical dimension of the coal seam 15. The elongated diameter cavity 20 is formed using techniques and suitable sub-countersink equipment. A vertical portion of the substantially vertical borehole 12 continues below the elongated diameter cavity 20 to form a reservoir 22 for the cavity 20. An articulated borehole 30 extends from the surface 14 to the elongated diameter bore 20 of the substantially vertical borehole 12. Jointed borehole 30 includes a substantially vertical portion 32, a substantially horizontal portion 34, and a curved or radial portion 36 interconnecting the vertical and horizontal portions 32 and 34. The horizontal portion 34 is substantially in the horizontal plane of the coal seam 15 and intersect the large diameter cavity 20 of the substantially vertical borehole 12. The articulated borehole 30 is deviated a sufficient distance from the substantially vertical borehole 12 in the surface 14 to allow that a large radius curved section 36 and any desired horizontal section 34 is perfor ada before intersecting the elongated diameter cavity 20. To provide the curved portion 36 with a radius of 30m- 45m (100-150 feet), the articulated borehole 30 is deflected a distance of approximately 90 meters (300 feet) from the well substantially vertical probing 12. This spacing minimizes the angle of the curved portion 36 to reduce the friction in the perforation 30 during the drilling operations. As a result, the reach of the articulated drilling chain perforated through the articulated borehole 30 is maximized. The articulated borehole 30 is drilled using the articulated drill string 40 which includes a motor placed at the bottom of the bore and a suitable bit 42. Underground metering tanks are included while drilling (MWD) 44 into the drill string hinged 40 for controlling the orientation and direction of the borehole drilled by the motor and the drill 42. The substantially vertical portion 32 of the jointed bore 30 is not coated with suitable tubing 38. After the elongated diameter cavity has been successfully intersected by the articulated borehole 30, drilling continues through the cavity 20 using the drill string articulated 40 and the appropriate horizontal drilling apparatus to provide a substantially horizontal drainage pattern 50 in the coal seam 15. The substantially horizontal drainage pattern 50 and other such boreholes include slopes, corrugations and other inclinations of the seam. coal 15 or other underground areas. During this operation, gamma-ray recording tools and conventional metering devices may be employed while drilling, to control and direct the orientation of the drill bit to retain the drainage pattern 50 within the confines of the coal seam 15 to provide a substantially uniform coverage of a desired area within the coal seam 15. Additional information regarding the drain pattern is described in greater detail below in relation to Figures 4-7. During the drilling process the drainage pattern 50, the fluid or "drilling mud" is pumped down the articulated drilling chain 40 and circulated out of the drill string 40 in the vicinity of the bit 42, where it is Use to wash the formation and remove training cuts. The cuts are then introduced into the drilling fluid that flows through the ring between the chain of perforation 40 and the walls of the borehole until it reaches the surface 14, where the cuts are removed from the drilling fluid and the fluid is then recirculated. This conventional drilling operation produces a standard drilling fluid column having a vertical height equal to the depth of the borehole 30 and produces a hydrostatic pressure on the borehole corresponding to the depth of the borehole. Because coal seams tend to be porous and fractured, they may be unable to sustain such hydrostatic pressure, even if water is also present in the formation in the coal seam 15. Consequently, if all hydrostatic pressure is allowed to occur. act on the coal vein 15, the result can be the loss of the drilling fluid and the cuts trapped in the formation. Such circumstances are known as an "over-balanced" drilling operation in which the hydrostatic fluid pressure in the borehole exceeds the capacity of the formation to withstand pressure. The loss of drilling fluids in cuts to the formation is not only expensive in terms of the area of the drilling fluids, which should rise, but tends to clog the pores in the coal vein 15, which are necessary to drain the vein of gas and water coal. l To avoid over-bore drilling conditions during the formation of the drainage pattern 50, air compressors 60 are provided to circulate compressed air downward toward the substantially vertical borehole 12 and back up through the borehole 30. The circulated air will mix with the drilling fluids in the ring around the articulated drilling chain 40 and create bubbles through the column of the drilling fluid. This has the effect of lightening the hydrostatic pressure of the drilling fluid and reducing the pressure at the bottom of the drilling sufficiently, so that the drilling conditions do not become overbalanced. The aeration of the drilling fluid reduces the pressure at the bottom of the drilling to approximately 10.55 - 14 kg / cm2 (150-200 pounds per square inch (psi)). As a result, coal seams can be drilled from the low pressure underground areas without substantial loss of drilling fluid and contamination of the area by the drilling fluid. The foam, which can be comprised of air mixed with water, can also be circulated downwards, through the articulated drilling chain 40 together with the drilling mud to aerate the perforation in the ring as the articulated borehole 30 is being drilled and, if desired, when the drainage pattern 50 is drilled. Drainage pattern drilling 50 with the use of an air drilling hammer or an engine at the bottom of the air-operated drilling will also supply compressed air or foam to the drilling fluid. In this case, the compressed air or foam that is used to drive the bit or the motor at the bottom of the bore comes out in the vicinity of the drill bit 42. However, the largest volume of air that can be circulated to down, towards the substantially vertical borehole 12, allows a greater aeration of the drilling fluid than is generally possible by the air supplied through the articulated drilling chain 40. FIGURE 2 illustrates a method and system for drilling the drainage pattern 50 in the coal seam 15 according to another embodiment of the present invention. In this embodiment, the substantially vertical borehole 12, the elongated diameter cavity 20 and the articulated borehole 32 are positioned and formed as described above in relation to FIGURE 1. Referring to FIGURE 2, after the intersection of the elongated diameter cavity 20 by the Jointed borehole 30 a pump 52 is installed in the elongated diameter cavity 20 to pump drilling fluid and cuts the surface 14 through the substantially vertical borehole 12. This eliminates air friction and the fluid returning to above, to the articulated borehole 30 and reduces the pressure at the bottom of the borehole to almost zero. As a result, access can be had to coal seams and other underground areas that have ultra-low pressures below 10.55 kg / cm2 (150 pounds per square inch (psi)) from the surface. Additionally, the risk of combining air and methane in the well is eliminated. FIGURE 3 illustrates the production of fluids from the horizontal drain pattern 50 in the coal seam 15 according to one embodiment of the present invention. In this embodiment, after the substantially vertical and articulated sounding wells 12 and 30, as well as the drainage pattern 50 have been drilled, the articulated drilling chain 40 is removed in the articulated borehole 30 and the borehole articulated is covered. For the multiple articulated structure described below, the articulated well 30 can be sealed in the substantially horizontal portion 34. Otherwise, the articulated well 30 can be left unobstructed.

Referring to FIGURE 3, a pump for the bottom of the perforation 80 is placed in the substantially vertical borehole 12 in the elongated diameter cavity 22. The elongated cavity 20 provides a reservoir for accumulated fluids that allows intermittent pumping without effects adverse effects of a hydrostatic head caused by fluids accumulated in the borehole. The pump at the bottom of the bore 140 is connected to the surface 14 via a line of pipe 82 and can be driven by extraction members 84 extending downwards through the borehole 12 of the pipe. The extraction pumps 84 oscillate by means of a suitable surface mounted apparatus, such as a powered rocker 86 for operating the bottom pump of the drill 80. The bottom pump of the drill 80 is used to remove the water and fine particles of coal trapped from the coal seam 15 via drainage pattern 50. Once the water is removed to the surface, it can be treated for the separation of methane, which can be dissolved in the water and removed the fine particles trapped. After sufficient water has been removed from the coal seam 15, the pure gas from the coal seam can be allowed to flow to the surface 14 through the ring of the substantially vertical borehole 12 around the line of pipe 82 and removed via the pipe attached to the wellhead apparatus. On the surface, the methane is treated, compressed and pumped through a pipe to be used as fuel in a conventional manner. The bottom pump of the bore 80 can be operated continuously or as needed to remove the water drained from the water seam 15 into the elongated diameter cavity 22. FIGS. 4-7 illustrate substantially vertical drainage patterns 50 for access to the coal seam 15 or other underground zone according to one embodiment of the present invention. In this embodiment, the drainage patterns comprise articulated patterns having a central diagonal with sides arranged in a generally symmetrical manner and properly spaced extending from each side of the diagonal. The articulated pattern approximates the pattern of veins in a sheet or the design of a pen having similar, substantially parallel, auxiliary drainage holes arranged in substantially equal and parallel spans or opposite sides of an axis. The articulated drainage pattern with its central perforation and auxiliary drainage perforations arranged in a generally symmetrical and separate manner properly on each side provide a uniform pattern for draining fluids from a coal vein or other underground formation. As described in more detail below, the articulated pattern provides substantially uniform coverage of a square, or quadrilateral, other type or grid area, and can be aligned with longwall mining panels to prepare the coal seam 15 for operations of mining. It will be understood that other suitable drainage patterns may be utilized in accordance with the present invention. Articulated and other suitable drainage patterns drilled from the surface provide access from the surface to underground formations. The drainage pattern can be used to remove and / or insert fluids uniformly or otherwise manipulate an underground reservoir. In applications other than coal, the drainage pattern can be used by initiating burn operations in your "steam blow" for heavy crude oil, and the removal of hydrocarbons from reservoirs of low porosity. FIGURE 4 illustrates an articulated drainage pattern 100 according to one embodiment of the present invention. In this mode, the articulated drainage pattern 100 provides access to an area substantially square 102 of an underground zone. A number of articulated patterns 60 can be used together to provide uniform access to a large underground region. Referring to FIGURE 4, the elongated diameter cavity 20 defines a first corner of the area 102. The articulated pattern 100 includes a substantially vertical main borehole 104 that extends diagonally through the area 102 to a distant corner 106 of the area 120 Preferably, the substantially vertical and articulated boreholes 12 and 30 are positioned over the area 102, so that the diagonal bore 104 is drilled up the slope of the coal vein 15. This will facilitate the collection of water , gas from the area 102. The diagonal perforation 104 is perforated using the articulated drilling chain 40 and extends from the elongated cavity 20 in alignment with the articulated borehole 30. A plurality of drill holes 110 extend from opposite sides. of the diagonal perforation 104 to a periphery 112 of the area 102. The lateral perforations 122 can be mirror images between each other. i on the opposite sides of the diagonal perforation 104 or they may be deviated between if along the diagonal perforation 104. Each of the side perforations 110 includes a curved radius portion 114 that comes from the diagonal perforation 104 and an elongated portion 116 formed after the curved portion 114 has reached a desired orientation. For uniform coverage of the square area 102, pairs of side perforations 110 are substantially uniformly spaced on each side of the diagonal perforation 104 and extend from the diagonal 64 at an angle of approximately 45 degrees. The side perforations 110 support the length, based on the progress from the elongated diameter cavity 20 to facilitate the perforation of the side perforations 110. The articulated drainage pattern 100 using a single diagonal perforation 104 and five pairs of side perforations 110 can drain an area of coal seam approximately 150 acres in size. Where a smaller area is to be drained, or where the coal seam has a different shape, such as a long, narrow shape or due to the topography of the underground surface, alternating articulated drainage patterns can be employed by varying the angle of the side perforations 110 towards the diagonal perforation 104 and the orientation of the perforations lateral 110. Alternatively, lateral perforations 120 may be perforated from only one side of the diagonal perforation 104 to form a half-hinged pattern. The diagonal perforation 104 and the side perforations 110 are formed by drilling through the elongated diameter cavity 20 using the articulated drilling chain 40 and the appropriate horizontal drilling apparatus. During this operation, gamma-ray recording tools and measurement technologies while drilling conventional can be employed to control the direction and orientation of the drill bit to retain the drainage pattern within the confines of the coal seam 15 to maintain the proper spacing and orientation of the diagonal and side perforations 104 and 110. In a particular embodiment, the diagonal perforation 104 is perforated with an inclination at each of the plurality of lateral emergency stop points 108. After the diagonal 104 is completed, the articulated drilling st 40 is returned upward to each successive lateral point 108 from which a side perforation 110 is punched on each side of the diagonal 104. It will be understood that the articulated drainage pattern 100 can be formed from otherwise suitable in accordance with the present invention. FIGURE 5 illustrates an articulated drainage pattern 120 according to another embodiment of the present invention. In this embodiment, the articulated drainage pattern 120 drains a substantially rectangular area 122 of the coal seam 15. The articulated drainage pattern 120 includes a main diagonal perforation 124 and a plurality of side perforations 126 that are formed as described in relation to the diagonal and lateral perforations 104 and 110 of FIGURE 4. For the substantially rectangular area 122, however, the lateral perforations 126 on a first side of the diagonal 124 include a shallow angle, while the side perforations 126 on the opposite diagonal side 124 include a step angle to provide together a uniform coverage of the area 12. FIGURE 6 illustrates an articulated drainage pattern quadrilateral 140 according to another embodiment of the present invention. The quadrilateral drainage pattern 140 includes four discrete articulated drainage patterns 100, each draining a quadrant of a region 142 covered by the articulated drainage pattern 140.

Each of the articulated drainage patterns 100 includes a diagonal drilling well 104 and a plurality of side probing wells 110 extending from the diagonal drill hole 104. In the quadrilateral mode, each of the diagonal and lateral drilling 104 and 110 are drilled from a common articulated borehole 141. This allows narrowing of the separation of the production equipment from the surface, a wider coverage of a drainage pattern reduces equipment and drilling operations. FIGURE 7 illustrates the alignment of articulated drainage patterns 100 with underground structures of a coal seam to degas and prepare the coal seam for mining operations in accordance with one embodiment of the present invention. In this mode, the coal seam 15 is subjected to mining operations using a long wall process. It will be understood that the present invention can be used to degas coal seams for other types of mining operations. Referring to FIGURE 7, the coal panels 150 extend longitudinally from a long wall 152. In accordance with the long-wall mining practices, each panel 150 is subsequently subjected to mining operations from a distant end towards the long wall 152 and it is allowed to dig and fracture the roof of the mine towards the opening after the mining process. Prior to mining operations on the panels 150, articulated drainage patterns 100 are drilled in the panels 150 from the surface to degas the panels 150 after the mining operations. Each of the articulated drainage patterns 100 is aligned with the long wall 152 and the panel 150 and covers portions of one or more panels 150. In this manner, a region of a mine can be degassed from the surface based on structures and underground restrictions. FIGURE 8 is a flow chart illustrating a method for preparing coal seam 15 for mining operations in accordance with one embodiment of the present invention. In this embodiment, the method begins at step 160 in which the areas to be drained and the drainage patterns 50 for the areas are identified. Preferably, the areas are aligned with the grid of a mining plan for the region. The articulated structures 100, 120 and 140 can be used to provide optimized coverage of the region. It will be understood that other suitable patterns can be used to degas the coal seam 15.

Proceeding to step 162, the substantially vertical well 12 is drilled from the surface 14 through the coal seam 15. Next, in step 164, the bottomhole logging equipment is used to accurately identify the location of the coal seam in the substantially vertical well 12. In step 164, the elongated diameter cavity 22 is formed in the substantially vertical borehole 12 in the place of the coal seam 15. As discussed above, the elongated diameter cavity 20 can be formed by sub-countersinking or other conventional shapes. Next, in step 166 the articulated borehole 30 is drilled to intercept the elongated diameter cavity 22. In step 168, the main diagonal bore 104 for the articulated drainage pattern 100 is drilled through the articulated borehole 30 towards the coal seam 15. After the formation of the main diagonal 104, side perforations 110 are drilled for the articulated drainage pattern 100 in step 170. As described above, the side emergency stop points can be formed in the diagonal perforation 104 during its formation to facilitate the perforation of the lateral perforations 110.

In step 172, the articulated borehole 30 is capped. Next, in step 174, the elongated diagonal cavity 22 is cleaned in preparation for installation of the production equipment at the bottom of the bore. The elongated diameter well 22 can be cleaned by pumping compressed air down to the substantially vertical borehole 12 or other suitable techniques. In step 176, the production equipment is installed in the substantially vertical borehole 12. The production equipment includes an extraction pump that extends downward toward the cavity 22 to remove water from the coal seam 15. Water removal will drop the pressure of the coal seam and allow the methane gas to diffuse and be produced upwards through the ring of the substantially vertical borehole 12. Proceeding to step 178, the water that is drained from the pattern of drain 100 towards cavity 22 is pumped to the surface with extraction pumping unit. The water can be pumped continuously or intermittently, as necessary, to remove it from the cavity 22. In step 180, the methane gas diffusing from the coal seam 15 is continuously collected on the surface 14. Next , in decision step 182, it is determined whether the production of gas from coal seam 15 is complete. In one mode, gas production can be completed after the gas collection costs exceed the profits generated by the well. In another mode, the gas can continue to be produced from the well until the remaining level of gas in the coal seam 15 is below the levels required for mining operations. If the gas production is not complete, the branch NO of decision step 182 returns to step 178 and 180 in which water and gas continue to be removed from the coal seam 15. After completion of production, the SI branch of the Decision step 182 leads to step 184 in which the production equipment is removed. Next, decision step 186 is determined if the coal seam 15 is to be prepared additionally for mining operations. If the coal seam 15 is to be -prepared additionally for mining operations, the SI branch of decision step 186 leads to step 188 in which water or other additives can be injected back into the coal seam 15 to rehydrate the coal vein and to reduce the dust to a minimum, to improve the efficiency of mining, and to improve the mined product.

Step 188 and branch No of step 186 lead to step 190 in which the coal seam is subjected to mining operations. The removal of the coal vein causes the mined roof to sink and fracture towards the opening after the mining process. The collapsed roof creates a fill mass gas which can be collected in the passage 192 through the substantially vertical borehole 12. Consequently, no additional drilling operations are required to recover mass gas from a submitted coal seam. to mining operations. Step 192 leads to the end of the process by which a coal seam is efficiently degassed from the surface. The method provides a symbiotic relationship to remove undesirable gas before mining operations and to rehydrate the coal before the mining process. FIGURES 9A through 9C are diagrams illustrating the deployment of a pump in the well cavity 200 according to one embodiment of the present invention. Referring to FIGURE 9A, the well cavity pump 20 comprises a portion of the borehole 202 and a positioning device in the cavity 204. The portion of the borehole 202 comprises an inlet 206 for extracting and transferring the fluid from the well. well contained within the cavity 20 to a surface of the borehole 12. In this embodiment, the positioning device in the cavity 204 is rotatably coupled to the portion of the borehole 202 to provide rotational movement to the positioning device of the well. cavity 204 in relation to the portion of the borehole 202. For example, a bolt, arrow, or other suitable method or device (not shown explicitly) can be used to rotatably couple the positioning device in the cavity 204 to the portion of the borehole 202 to provide rotational movement to the positioning device in the cavity 204 about an axis 208 relative to the portion of the borehole 202. In this way, the positioning device in the cavity 204 can be coupled to the portion of the borehole 202 between an end 210 and an end 212 of the positioning device in the cavity 204, so that both ends 210 and 212 can be manipulated in a rotatable manner in relation to the portion of the well 202. The positioning device in the cavity 204 also comprises a counterbalance portion 214 for control a position of the ends 210 and 212 in relationship to the polling portion 202 in a generally unsupported condition. For example, the positioning device in the cavity 204 is generally raised about the axis 208 relative to the position of the borehole 202. The counterbalance portion 214 is positioned along the positioning device in the cavity 204 between the shaft 208 and end 210, so that a weight or mass of the counterbalance portion 214 counterbalances the positioning device in the cavity 204 during deployment and removal of the pump from the well cavity 200 relative to the vertical borehole 12 and the cavity 20. In operation, the positioning device in the cavity 204 is deployed in the vertical borehole 12 having the end 210 and the counterbalance portion 214 placed in a generally retracted condition, thereby placing the end 210 and the counterbalance portion 214 adjacent to the portion of the borehole 202. As the pump in the well cavity 200 moves downwardly inside the vertical borehole 12 in the direction indicated generally by the arrow 216, a length of the positioning device in the cavity 204 generally prevents the rotational movement of the positioning device of the cavity 204 in relation to the portion of the borehole 202. For example, the mass of the counterbalance portion 214 can cause the counterbalance portion 214 and the end 212 to be generally supported by contact with a vertical wall 218 of the tailored vertical borehole 12 that the well cavity pump 200 moves downwardly into the vertical borehole 12. Referring to FIGURE 9B, as the well cavity pump 200 moves downward into the vertical borehole 12, the counterbalance portion 214 causes the rotational or rotational movement of the positioning device in the cavity 204 relative to the portion of the bore 202 as the positioning device in the cavity 204 passes from the borehole 12 to the cavity 20 For example, when the positioning device in the cavity 204 transits from the vertical borehole to the cavity 20, the counterbalance portion 214 and the end 212 are generally nte not supported by the vertical wall 218 of the vertical borehole 12. When the counterbalance portion 214 and the end 212 are generally not supported, the counterbalance portion 214 automatically causes the rotational movement of the positioning device in the cavity 204 in relation to to the portion of the borehole 202. By example, the counterbalance portion 214 generally causes the end 210 to rotate or extend outwardly relative to the vertical borehole 12 in the direction indicated generally by the arrow 220. Additionally, the end 212 of the positioning device in the cavity 204 extends or rotates outward relative to vertical borehole 12 in the direction indicated generally by arrow 222. The length of positioning device in cavity 204 is configured such that ends 210 and 212 of the device of positioning 204 are generally not supported by a vertical borehole 12 when the positioning device in the cavity 204 transits from the vertical borehole 12 to the cavity 20, thereby allowing the counterbalance portion 214 to cause rotational movement of the end 212 outwardly relative to the portion of the borehole 202 and beyond the annular portion 224 of the header 2 2. In this way in operation, when the positioning device in the cavity 204 transits from the vertical borehole 12 to the cavity 20, the counterbalance portion 214 causes the end 212 to rotate or extend outwards in the indicated direction generally by the arrow 222, so that the continuous downward displacement of the pump of the Well cavity 200 results in contact of end 12 with horizontal wall 226 of cavity 20. Referring to FIGURE 9C, as the downward displacement of the pump from well cavity 200 continues, the end contact 212 with the horizontal wall 226 of the cavity 20 causes additional rotational movement of the positioning device in the cavity 204 relative to the portion of the borehole 202. For example, the contact between the end 212 and the horizontal 226 combined with the Downward displacement of the well cavity pump 200 causes the end 210 to extend or rotate relative to the vertical borehole 12 in the direction indicated generally by the arrow 228 until the counterbalance portion 214 comes into contact with a horizontal wall 230 of the cavity 20. Once the counterbalance portion 214 and the end 212 of the positioning device in the cavity 204 are supported in a manner In general by the horizontal walls 226 and 230 of the cavity 20, the continuous downward displacement of the well cavity pump 200 is substantially prevented, thereby positioning the inlet 206 at a predefined location within the cavity 20. In this way, the inlet 206 can be located in various positions along the portion of the well of probing 202, so that the inlet 206 is placed in a predefined location within the cavity 20 when the positioning device in the cavity 204 bottoms into the cavity 20. Therefore, the entry 2? 'd can be placed exactly within the cavity 20 to substantially prevent drainage of debris or debris or other material placed within the collector or rat hole 22 and to prevent interference of the gas caused by the placement of the inlet 20 in the narrow borehole. Additionally, the inlet 206 may be placed within the cavity 20 to maximize the fluid station of the cavity 20. In reverse operation, the upward displacement of the pump from the well cavity 200 will generally result in the release of contact between the counterbalance portion 214 and the end 212 with the horizontal walls 230 and 226, respectively. When the positioning device of the cavity 204 is generally not supported within the cavity 20, the mass of the positioning device in the cavity 204 positioned between the end 212 and the shaft 208 generally causes the positioning device in the cavity 204 to rotate in opposite directions to the directions indicated generally by arrows 220 and 222 as illustrated in FIGURE 9B. Additionally, the counterbalance portion 214 cooperates with the mass of positioning devices in the cavity 204 positioned between the end 212 and the shaft 208 to generally align the positioning device in the cavity 204 with the vertical borehole 12. in this mode, the positioning device of the cavity 204 is automatically aligned with the vertical sampling well 12 as the pump of the cavity of the well 200 is withdrawn from the cavity 20. The additional upward displacement of the pump of the cavity from the well 200 can then be used to remove the positioning device in the cavity 204 from the cavity 20 and the vertical borehole 12. Therefore, the present invention provides greater reliability than previous systems and methods to positively locate the entry 206 of the well cavity pump 200 in a predefined location within the cavity 20. Additionally, the pump cavity of the well Well 200 can be efficiently removed from cavity 20 without requiring additional unlocking or aligning tools to facilitate removal of pump from well well 200 from cavity 20 and vertical sounding well 12.

Although the present invention has been described with various modalities, various changes and modifications can be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications so that they fall within the scope of the appended claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (88)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. 1. A method for accessing an underground area from the surface, characterized in that it comprises: drilling a plurality of substantially vertical boreholes from the surface to the underground zone; drill an articulated borehole from the surface to the underground zone, the articulated borehole horizontally deviated from each of the boreholes substantially vertical to the surface and intersecting each of the substantially vertical boreholes in a nearby joint to the underground zone; and drilling through the articulated borehole a substantially horizontal drainage pattern extending from each of the junctions to the underground zone.
2. 2. The method according to claim 1, characterized in that it also comprises: forming an elongated cavity in each of the substantially vertical sounding wells near the underground zone; drilling the articulated sounding well to intersect the elongated cavity of each of the substantially vertical sounding wells; and drilling through the articulated borehole substantially horizontal drainage patterns from each of the elongated cavities to the underground zone.
3. 3. The method according to claim 1, characterized in that the underground zone comprises a coal seam.
4. 4. The method according to claim 1, characterized in that the underground zone comprises an oil reservoir. The method according to claim 1, characterized in that it further comprises producing fluid from the underground zone through the substantially vertical boreholes. 6. The method according to claim 1, characterized in that it also comprises: installing a pumping unit substantially vertical extraction in each of the wells of probing substantially vertical with a pump inlet near the corresponding joint; and operating the substantially vertical extraction pumping unit to produce fluid from the underground zone. The method according to claim 1, characterized in that the underground zone comprises a low pressure zone. The method according to claim 1, characterized in that the drilling of substantially horizontal drainage patterns from each of the joints to the underground zone comprises: drilling a substantially horizontal borehole from each of the joints defining a first end of an area in the underground zone to a far end of the area; drilling a first set of substantially horizontal side boreholes in spaced apart relation from the substantially horizontal borehole to a periphery of the area of a first side of the substantially horizontal borehole; and drilling a second set of substantially horizontal side boreholes in spaced apart relation from the borehole substantially horizontal to a periphery of the area on a second opposite side of the substantially horizontal borehole. The method according to claim 8, characterized in that the side boreholes each extend substantially at an angle of about 45 degrees from the substantially horizontal borehole. 10. The method according to claim 8, characterized in that the area in the underground zone is essentially quadrilateral in shape. The method according to claim 8, characterized in that the area in the underground zone is substantially square in shape. The method according to claim 1, characterized in that the drilling of substantially horizontal drainage patterns from each of the junctions in the underground zone, comprises: drilling the drainage patterns using an articulated drilling chain extending through of the articulated borehole and joints; supply drilling fluid downwards, through the articulated drilling chain and again upwards through a ring between the articulated drilling chain and articulated drilling well to remove the cuts generated by the articulated drilling chain in the drilling of drainage patterns; "Inject a drill gas into the substantially vertical drilling wells, and mix the drilling gas with the drilling fluid at the joints to reduce the hydrostatic pressure on the underground area while drilling the drainage patterns. according to claim 12, characterized in that the drilling gas comprises air 14. The method according to claim 12, characterized in that the underground zone comprises a low pressure reservoir having a pressure lower than 17.6 kg / cm2 ( 250 pounds per square inch (psi)) 15. The method according to claim 1, characterized in that drilling substantially horizontal drainage patterns from each of the junctions in the underground zone comprises: drill the drainage patterns using an articulated drill string that extends through the articulated borehole and joints; supply drilling fluid down, through the articulated drilling chain to remove the cuts generated by the drill string in the drilling of drainage patterns, and pump drilling fluid with cuts up through the wells sound substantially vertical to reduce the hydrostatic pressure on the underground zone during the drilling of drainage patterns 16. The method according to claim 15, characterized in that the underground zone comprises a low pressure reservoir having a lower pressure than the 10.55 kg / cm2 (150 pounds per square inch (psi)) 17. A system for accessing an underground area from the surface, characterized in that it comprises: a plurality of substantially vertical sounding wells extending from the surface to the underground zone, an articulated sounding well that extends from the surface to the sub-zone erránea, the well of The articulated sounding is horizontally offset from each of the sounding wells substantially vertical on the surface and intersecting each of the substantially vertical sounding wells at a junction near the underground zone; and a substantially horizontal drainage pattern that extends from each of the joints to the underground zone. 18. The system according to claim 17, characterized in that each of the joints further comprises an elongated cavity formed in the corresponding substantially vertical borehole proximate to the underground zone. 19. The system according to claim 17, characterized in that the underground zone comprises a coal vein. 20. The system according to claim 17, characterized in that the underground zone comprises an oil reservoir. 21. The system according to claim 17, characterized in that the underground zone comprises a low pressure reservoir. 22. The system according to claim 17, characterized in that the underground zone comprises an ultralow pressure reservoir which has a pressure lower than 10.55 kg / cm2 (150 pounds per square inch (psi)). The system according to claim 17, characterized in that it further comprises a substantially vertical extraction pumping unit placed in at least one of the substantially vertical boreholes and operating to pump the drained fluid from the underground zone to the corresponding union to the surface. 24. The system according to claim 23, characterized in that the substantially vertical extraction pumping unit comprises an extraction pump. 25. The system according to claim 17, characterized in that each of the substantially horizontal drain patterns comprises: a substantially horizontal borehole extending from the corresponding junction defining a first end of an area in the underground zone until a distant end of the area; a first set of substantially horizontal side boreholes in spaced apart relation extending from the substantially horizontal borehole to a periphery of the area on a first side of the substantially horizontal borehole; and a second set of laterally sounding wells substantially horizontal in spaced relation to each other, extending from the substantially horizontal borehole to the periphery of the area on a second, opposite side of the substantially horizontal borehole. 26. The system according to claim 25, characterized in that the side boreholes each extend substantially at an angle of about 45 degrees from the substantially horizontal borehole. 27. The system according to claim 25, characterized in that the area in the underground zone is substantially quadrilateral in shape. 28. The system according to claim 25, characterized in that the area of the underground zone is substantially square in shape. 29. A substantially horizontal underground drainage pattern for accessing an area of an underground zone from the surface, characterized in that it comprises: a substantially horizontal borehole extending from a surface borehole that defines a first end of the area in the underground zone to a far end of the area; a first set of substantially horizontal lateral boreholes extending in spaced relation from each other from the substantially horizontal borehole on a first side of the substantially horizontal borehole; and a second set of substantially horizontal side boreholes extending in spaced relation from each other from the substantially horizontal borehole on a second opposite side of the diagonal, where the length of each of the first and second sets of boreholes laterally decreases with the distance between each well of lateral sounding and increase of the surface sounding well. 30. The underground drainage pattern according to claim 29, characterized in that the lateral boreholes extend to a periphery of the area. 31. The underground drainage pattern according to claim 29, characterized in that the lateral boreholes each extend substantially at an angle of between 40 and 50 degrees from the substantially horizontal borehole. 32. The underground drainage pattern according to claim 29, characterized in that the side boreholes each extend substantially at a 45 degree angle from the substantially horizontal borehole. 33. The underground drainage pattern according to claim 29, characterized in that the area substantially comprises a quadrilateral and the ends comprise distant corners of the quadrilateral. 34. The underground drainage pattern according to claim 29, characterized in that the area substantially comprises a square and the ends comprise opposite ends of the square. 35. The underground drainage pattern according to claim 29, characterized in that the substantially horizontal lateral wells provide a substantially uniform coverage of the area. 36. The underground drainage pattern according to claim 29, characterized in that the side boreholes in each set are substantially uniformly spaced from each other. 37. A structure for accessing a region of an underground zone, characterized in that it comprises: a first substantially vertical borehole substantially defining one end of the first area of the region; a second substantially vertical borehole substantially defining an end of a second area in the region adjacent to the first area; an articulated borehole including a first portion intersecting the first substantially vertical borehole at a first junction and a second portion intersecting the second substantially vertical borehole at a second junction; a first substantially horizontal diagonal borehole, extending from the first joint in line with the first portion of the borehole jointed to a distal end of the first area; a second horizontally substantially diagonal sounding well, extending from the second joint in line with the second portion of the sounding well articulated to a distal end of the second area; and each diagonal borehole comprises a plurality of substantially lateral lateral boreholes extending from the borehole diagonal to a periphery of the area containing the diagonal borehole. 38. The structure according to claim 37, characterized in that the side boreholes extend from each of the diagonal boreholes, comprising: a first set of lateral boreholes extending from the diagonal borehole to the periphery of the area on a first side of the diagonal borehole; and a second set of lateral boreholes extending from the diagonal borehole to the periphery of the area on a second opposite side of the diagonal borehole. 39. The structure according to claim 38, characterized in that the lateral boreholes are substantially uniformly spaced from each other. 40. The structure according to claim 38, characterized in that the side boreholes progressively shorten as they progress from the substantially vertical borehole of the area. 41. The structure according to claim 37, characterized in that it also comprises: a third substantially vertical borehole substantially defining an end of a third area; a fourth substantially vertical borehole substantially defining an end of a fourth area; the articulated borehole includes a third portion intersecting the third substantially vertical borehole at a third junction and a fourth portion intersecting the fourth substantially vertical borehole at a fourth junction; a third substantially horizontal diagonal sampling well extending from the third junction in line with the third probing portion hinged to a distal end of the third area; and a fourth substantially horizontal diagonal probing well extending from the fourth junction in line with the fourth probing portion hinged to a distal end of the fourth area. 42. A method for forming an underground drainage pattern to access an area of an underground zone from the surface, characterized in that it comprises: drilling through an articulated borehole a substantially horizontal borehole from a first end to a second end of the area of the underground zone; tilting the substantially horizontal borehole at each of the plurality of lateral points; and after drilling the substantially horizontal drilling well with an articulated drilling chain, returning the articulated drilling chain to each successive lateral point and drilling a plurality of lateral drilling wells from the lateral points extending from each side of the drilling well. probing substantially horizontally and to a periphery of the area, where the length of each of the lateral probing wells decreases progressively with the distance between each lateral point and the first end of the area is increased. 43. The method according to claim 42, characterized in that it further comprises substantially uniformly separating the lateral points along the substantially horizontal borehole. 44. The method according to claim 42, characterized in that it also comprises drilling the side boreholes from each point laterally at substantially a 45 degree angle from the horizontal borehole. 45. The method according to claim 42, characterized in that the area is substantially quadrilateral in shape. 46. The method according to claim 42, characterized in that the area is substantially square in shape. 47. The method according to claim 42, characterized in that the first and second ends define opposite corners of the area. 48. A method for preparing an underground zone for mining operations, characterized in that it comprises: drilling a substantially vertical borehole from the surface to the underground zone; drilling an articulated borehole from the surface to the underground zone, the articulated borehole is horizontally offset from the borehole substantially vertical on the surface and intersects the substantially vertical borehole at a junction near the underground zone; drilling through the articulated borehole a substantially horizontal drainage pattern from the junction to the underground zone; drain water from the underground area through the drainage pattern to the junction; pumping the water from the junction to the surface through the substantially vertical borehole; and producing gas from the underground zone through at least one of the substantially vertical and articulated boreholes. 49. The method according to claim 48, characterized in that the joint comprises an elongated cavity • formed in the substantially vertical borehole. 50. The method according to claim 48, characterized in that the underground zone comprises a coal seam. 51. The method according to claim 48, characterized in that it further comprises: installing a substantially vertical extraction pumping unit in the substantially vertical borehole with a position of the pump inlet near the joint; pump water from the junction to the surface through the substantially vertical extraction pumping unit. 52. The method according to claim 48, characterized in that the underground zone comprises a low pressure zone. 53. The method according to claim 48, characterized in that drilling substantially horizontal drain patterns from the junction comprises: drilling a diagonal borehole from the junction defining a first end of an area aligned with an underground coal panel to an opposite corner of the area; drilling a plurality of lateral wells on each side of the diagonal borehole towards one or more hard coal panels. 54. The method according to claim 53, characterized in that the drainage pattern comprises an articulated structure. 55. The method according to claim 48, characterized in that it also comprises rehydrating the underground zone after completing the degassing of the underground zone by pumping water into the underground zone through the drainage pattern. 56. The method according to claim 55, characterized in that it comprises, In addition, pump additives into the underground area through the drainage pattern. 57. The method according to claim 48, characterized in that it also comprises producing solidification gas from the underground zone through at least one of the substantially vertical and articulated fluid wells after completing the mining operations of the area of the underground zone in which the drainage pattern extends. 58. A cavity well pump, characterized in that it comprises: a portion of the borehole having an operable inlet to extract fluid from the well from an underground cavity; and, a positioning device in the cavity coupled to the portion of the borehole, the positioning device in the cavity operates to extend from a first position to a second position within the underground cavity to place the entry in a predefined location within. of the underground cavity. 59. The cavity well pump according to claim 58, characterized in that the positioning device in the cavity is rotatably coupled to the well portion, and where the positioning device in the cavity operates to rotate from the first position to the second position. 60. The cavity well pump according to claim 58, characterized in that the positioning device in the cavity automatically extends from the first position to the second position when the positioning device in the cavity transits a vertical borehole to the underground cavity. 61. The cavity well pump according to claim 60, characterized in that the positioning device in the cavity further operates to retract from the second position to the first position when the positioning device in the cavity 'is removed from the cavity. underground 62. The cavity well pump according to claim 58, characterized in that the positioning device in the cavity comprises a first end and a second end, the positioning device in the cavity is rotatably coupled to the portion of the well between the first and second ends, the positioning device in the cavity has a counterbalanced portion positioned at the first end and which operates to rotate the second end outward toward the underground cavity when the Positioning device in the cavity transits from the vertical borehole to the underground cavity. 63. The cavity well pump according to claim 62, characterized in that the counterbalance portion further operates to align the positioning device in the cavity with the vertical probing well to extract the positioning device in the cavity of the cavity. underground 6 The cavity well pump according to claim 58, characterized in that the positioning device in the cavity comprises a first end and a second end, the first and second ends operate to extend outward in substantially opposite directions to place the device positioning in the cavity in the second position, and wherein the positioning device in the cavity operates to contact a portion of the underground cavity to place the entry in the predefined location. 65. The cavity well pump according to claim 58, characterized in that the positioning device in the cavity comes in contact with a portion of the underground cavity in the second position to substantially prevent the downward displacement of the entrance to a manifold. 66. A method to produce gas from an underground coal vein, the method is characterized in that it comprises: drilling a first, substantially vertical well, intersecting the coal seam; forming a cavity of elongated diameter in the first borehole to the depth of the coal seam; drilling a second drilling well deflected horizontally of the first borehole, the second borehole includes a substantially horizontal portion intersecting the cavity; and drilling a main drainage well, substantially horizontal, in the coal seam, the drainage well intersects the cavity, so that gas can be produced from the coal seam through the borehole. sewer system. 67. The method according to claim 66, characterized in that it additionally comprises the step of producing gas from the coal seam. 68. The method according to claim 67, characterized in that the coal seam It contains excess water and additionally comprises the steps of installing a pump in the cavity, draining the water from the coal seam through the drainage well, and pumping the water up through the borehole of the first well. 69. The method according to claim 66, characterized in that it additionally comprises drilling a plurality of secondary drainage boreholes in the coal seam, the drainage portions intersecting the main drainage borehole. 70. The method according to claim 69, characterized in that the main and auxiliary drainage wells form an articulated pattern. 71. A method for producing gas from an underground coal seam, the method is characterized in that it comprises: drilling a first substantially straight bore well from the surface to intersect the coal seam; register the first borehole to identify the depth of the coal seam; forming a cavity of elongated diameter in the first borehole substantially to the depth of the coal seam; drilling a borehole deviated from the surface to intersect the cavity; use the deviated borehole to drill a substantially horizontal main drainage borehole in the coal seam and intersect the cavity and a plurality of secondary drainage holes in the coal seam, each of the boreholes Secondary drainage intersect in the main drainage borehole; drain water from the coal seam through the secondary and main drainage wells into the cavity; pump the water from the cavity to the surface through the first borehole; flow gas from the coal seam through the secondary and main drainage wells; and driving the gas to the surface through the first borehole. 72. The method of compliance with the claim 71, characterized in that the main and secondary drainage boreholes form an articulated pattern. 73. A method for providing drainage wells in an underground coal seam, the method is characterized in that it comprises: providing a first, substantially straight, borehole extending from the surface to at least the depth of the coal seam; 'register the first borehole to identify the depth where the coal seam intersects the first borehole; elongating the diameter of the first borehole substantially to the depth of the coal seam to provide a cavity at substantially the depth of the coal seam and in communication with the first borehole; By drilling a horizontally offset deviated borehole from the first borehole, the borehole 'includes a substantially vertical portion extending from the surface to a depth less than the depth of the coal seam, a substantially horizontal portion intersecting the borehole. cavity, and a curved portion that connects the vertical and horizontal portions; use an articulated drill string that extends through the deviated borehole and the cavity to drill a main drainage well into the coal seam; supply drilling fluid down through the articulated drilling chain and back up through the ring between the deviated borehole and the articulated drilling chain to remove cuts from the main drainage borehole; and mixing compressed air with the drilling fluid to reduce the hydrostatic pressure in the main drilling hole to thereby decrease the possibility of overbalanced drilling conditions in the drilling hole. 74. The method according to claim 73, characterized in that at least a portion of the compressed air is supplied through the articulated drilling chain. 75. The method according to claim 73, characterized in that at least a portion of the compressed air is supplied through the first borehole. 76. The method according to claim 73, characterized in that it additionally comprises the steps of removing the articulated drilling chain from the drainage well and the deviated borehole; cover the deviated borehole; drain the water and gas that flows from the coal seam through the drainage well; drive water to the surface through the main borehole; and 'driving the methane gas to the surface through the main borehole. 77. In a process for coal mining operations, in a vein of underground coal, the improvement is characterized because it includes: subjecting the coal seam to operations prior to mining to remove excess water and dangerous gases from it before submitting to coal mining operations in the coal seam, operations prior to mining include, 'providing a substantially straight borehole communicating between the surface and the coal seam; providing an elongated diameter cavity in the borehole at approximately the depth of the coal seam; drilling a substantially horizontal drainage hole in the coal seam, the drainage hole communicates with the cavity; drain excess water and flow hazardous gases from the coal seam through the drainage well and into the cavity; driving water and hazardous gases from the cavity to the surface through the substantially straight borehole; and continue the steps of draining water and flowing the gas from the coal seam and into the cavity and of driving the water and gas to the surface until the desired amounts of water and gas are removed from the coal seam. 78. The method according to claim 77, characterized in that it comprises additionally providing a plurality of secondary drainage wells in the coal seam in communication with the main drainage hole. 79. The method according to claim 78, characterized in that the main drainage perforation and the secondary drainage perforations form an articulated pattern. 80. A method for accessing an underground area from the surface, characterized in that it comprises: drilling a substantially vertical borehole from the surface to the underground zone; drill an articulated borehole from the surface to the underground zone, the articulated borehole deviated horizontally from the borehole sounding substantially vertical on the surface, the articulated borehole has at least a radius of 30 m (100 ft) and intersects the substantially vertical borehole at a junction near the underground zone; and 'drilling through the articulated borehole a substantially horizontal drainage pattern from the junction to the underground zone, the radius of at least 30 m (100 feet) of the articulated borehole reduces friction within the articulated borehole for extend a distance of the drain pattern from the joint. 81. The method according to claim 80, characterized in that it further comprises: forming an elongated cavity in the substantially vertical borehole near the underground zone; drilling the articulated borehole to intersect the elongated cavity; and drilling through the articulated borehole the substantially horizontal drain pattern from the elongated cavity to the underground zone. 82. The method according to claim 81, characterized in that the formation of the elongated cavity comprises forming the elongated cavity having a radius of approximately 2.4 m (8 feet). 83. A method for accessing an underground zone from the surface, characterized in that it comprises: drilling a substantially vertical borehole from the surface to the underground zone; drilling an articulated borehole from the surface to the underground zone, the articulated borehole deviated horizontally from the borehole substantially vertical on the surface and intersecting the substantially vertical borehole at a junction near the underground zone; drilling through the articulated borehole, a substantially horizontal drainage pattern that extends from the junction to the underground zone; and remove resources from the underground zone through the substantially vertical borehole. 84. The method according to claim 83, characterized in that it further comprises: installing a substantially vertical extraction pum unit in the substantially vertical borehole with a pump inlet near the joint; Y operate the pum unit substantially vertical extraction to produce resources from the underground zone. 85. A method for accessing an underground area from the surface, characterized in that it comprises: drilling a substantially vertical borehole from the surface to the underground zone; drilling an articulated borehole from the surface to the underground zone, the articulated borehole deviated horizontally from the borehole substantially vertical on the surface and intersecting the substantially vertical borehole at a junction near the underground zone; and drilling through the articulated borehole a substantially horizontal drainage pattern extending from the junction to the underground zone, the drainage pattern having a substantially horizontal borehole and a plurality of lateral boreholes extending from each side of the borehole substantially horizontal. 86. A method for producing gas from an underground coal seam, the method is characterized in that it comprises: drilling an orimer substantially vertical borehole, intersecting the coal seam; drilling a second horizontally deflected borehole from the first borehole, the second borehole includes a substantially horizontal portion intersecting the first borehole; 'drilling a substantially horizontal drainage borehole, in the coal seam, the drainage borehole extends from the intersection of the first and second boreholes; and produce gas from the coal seam through the drainage well and the first borehole. 87. A method for accessing an underground area from the surface, characterized in that it comprises: drilling a first borehole from the surface to the underground zone; drilling a second borehole that intersects the first borehole at a junction near the underground zone; the second borehole has a radius of at least 30m (100 feet); and drilling a substantially horizontal drainage pattern extending from the junction to the underground zone, the radius of at least 30 m (100 ft) from the second drilling well reduces the friction within the second drilling well to extend a distance from the standard of drainage from the union. 88. A method for accessing an underground zone from the surface, characterized in that it comprises: drilling a substantially vertical borehole from the surface to the underground zone; drilling an articulated borehole from the surface to the underground zone, the articulated borehole deviated horizontally from the borehole substantially vertical to the surface and intersecting the substantially vertical borehole at a junction near the underground zone; drilling through the articulated borehole a substantially horizontal drainage pattern that extends from the junction to the underground zone using an articulated drill string; supply drilling fluid down, through the articulated drilling chain and back up through the ring between the articulated drilling chain and the articulated borehole to remove cuts generated by the articulated drilling chain in the drilling pattern drainage; injecting a drill gas into the substantially vertical borehole; Y mix the drilling gas with the drilling fluid in the joint to reduce the hydrostatic pressure on the underground area while drilling the drainage pattern.