WO2015051414A1 - Ensemble coin et procédé - Google Patents

Ensemble coin et procédé Download PDF

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Publication number
WO2015051414A1
WO2015051414A1 PCT/AU2014/050275 AU2014050275W WO2015051414A1 WO 2015051414 A1 WO2015051414 A1 WO 2015051414A1 AU 2014050275 W AU2014050275 W AU 2014050275W WO 2015051414 A1 WO2015051414 A1 WO 2015051414A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas well
casing
wedge
assembly
well casing
Prior art date
Application number
PCT/AU2014/050275
Other languages
English (en)
Inventor
David MATHEW
Helmet Gunar DAMBERGS
Original Assignee
Wds (Oil & Gas) Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2013903884A external-priority patent/AU2013903884A0/en
Application filed by Wds (Oil & Gas) Pty Ltd filed Critical Wds (Oil & Gas) Pty Ltd
Publication of WO2015051414A1 publication Critical patent/WO2015051414A1/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/04—Directional drilling
    • E21B7/06—Deflecting the direction of boreholes
    • E21B7/061—Deflecting the direction of boreholes the tool shaft advancing relative to a guide, e.g. a curved tube or a whipstock
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/006—Production of coal-bed methane
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/30—Specific pattern of wells, e.g. optimising the spacing of wells
    • E21B43/305—Specific pattern of wells, e.g. optimising the spacing of wells comprising at least one inclined or horizontal well

Definitions

  • This invention is concerned with a wedge assembly.
  • the invention is concerned particularly, although not exclusively, with a gas well casing wedge.
  • Coal seam gas is gas trapped in underground coal seams.
  • unconventional gas can be trapped in shale and sandstone reservoirs and conventional gas can be trapped in sandstone reservoirs. It is desirable to utilise this gas, as gas fired power stations create less greenhouse gas emissions than coal fired power station.
  • a vertical well is drilled.
  • a surface to inseam lateral hole is then drilled from the surface remote from the vertical well, having a relatively large radius and then running horizontally along the coal seam for a relatively long distance (e.g. 1000m) to intersect the vertical well.
  • the wells are drilled such that they are initially vertical and then turn in a large radius to run horizontally along the coal seam. These wells are typically spaced at set intervals, for example at 500m x 1000m. Gas trapped in the coal seam, shale or sandstone reservoirs then typically permeates into the lateral hole and is extracted via the vertical well.
  • a problem with existing wells is that the turning of the inseam lateral hole or the well from vertical to horizontal must be carefully controlled so that the horizontal section runs along the coal seam, and in the case of a surface to inseam lateral hole, that the lateral hole also intersects the vertical well.
  • the invention resides in a wedge assembly for a gas weli casing, the wedge assembly comprising:
  • a wedge having a deflection face adapted to deflect a casing bit; and a hollow deployment casing adapted to lower the wedge down the gas well casing,
  • deployment casing has a plurality of ports adapted to have high pressure air injected therethrough to assist in bringing drilling fluid towards a top of the gas well casing.
  • the deflection face of the wedge is contoured to the shape of the casing bit.
  • the wedge is adapted to deflect the casing bit into an inner surface of the gas well casing to create an opening in the casing.
  • the deflection face is set at a predetermined angle relative to the longitudinal axis of the wedge assembly, the longitudinal axis of the wedge assembly being parallel to the longitudinal axis of the gas well casing when the wedge assembly is located in the gas well casing.
  • the predetermined angle forms an acute angle.
  • the wedge is formed from a cylindrical material. More preferably, the wedge is f ormed from a cylindrical piece of steel. Typically the defiection face is machined into the cylindrical material.
  • the wedge is secured to a wedge casing. More preferably the wedge is welded into a wedge casing.
  • the wedge casing will have an opening such that the deflection face is open to the gas well casing.
  • the casing bit is a casing mill bit. More preferably, the casing bit is a casing mill bit and reamer assembly. Preferably the casing bit forms an aperture in a portion of the gas well casing that is made from a material that is softer than the predominant material used for the gas well casing. Preferably the softer material is a composite material. Preferably the gas well casing is predominantly made of steel and the softer material is a fibreglass composite material. Alternatively, the gas well casing may be a steel gas well casing and the casing bit forms an aperture in the steel material of the gas well casing.
  • the wedge assembly further comprises a packer located near a lower end of th wedge.
  • the packer is adapted to seal a space between the gas well casing and the wedge assembly to prevent drill cuttings from migrating down the gas well casing.
  • the packer is attached to the wedge casing.
  • the wedge assembly further comprises a spacer operatively attached to a lower end of the wedge.
  • the spacer is adapted to position the wedge at a predetermined location within the gas well casing.
  • different length spacers may be utilised to position the wedge at different predetermined locations within the gas well casing.
  • the wedge assembly further comprises a direction assembly adapted to set the direction of the deflection face relative to the gas well casing.
  • the direction assembly is provided between the spacer and the wedge. !V ore preferably, the direction assembly is provided between the spacer and the packer.
  • the direction assembl is adapted to rotatably connect the upper part of the wedge assembly with the lower part of the wedge assembly such that once a predetermined direction of the upper part of the wedge assembly is achieved relative to the lower part, the direction assembly can be releasably locked to prevent further rotation.
  • an orientation assembly is adapted to orient the wedge assembly relative to the gas well casing.
  • part of the onentation assembly is secured relative to the bottom of the gas well casing.
  • the orientation assembly will have an upper orientation sub assembly and a lower orientation subassembly.
  • the upper and lower orientation subassemblies can be releasably secured to one another in only one orientation.
  • the upper onentation subassembly is secured to the wedge assembly and the lower orientation subassembly is secured relative to the bottom of the gas well casing.
  • the deployment casing is hollow so that a casing bit can be lowered through the deployment casing and deflected by the deflection face of the wedge.
  • the deployment casing will also acts as a conduit for drilling fluids.
  • an orientation indicator is provided towards the top of the deployment casing to aid in the orientation or to check the orientation of the wedge assembly.
  • the orientation indicator is an orientation flange attached to the top of the deployment casing.
  • the deployment casing has a plurality of ports through which high pressure air is injected. The high pressure air typically mingles with the drilling fluid returning to the surface to make this fluid lighter.
  • the wedge assembly further comprises a plurality of centraiisers adapted to centralise the wedge assembly in the gas well casing.
  • the centraiisers may be attached to the deployment casing such that they are positioned between the deployment casing and the gas well casing.
  • the gas well casing is a gas well casing used in a gas well for coal seam gas.
  • the gas well casing may be a gas well casing used in gas well for unconventional or conventional gas.
  • the gas well casing may be a gas well casing used in a gas well for sequestration of gas or liquids into suitable formations.
  • the gas well casing has at least one portion of material that is softer than the predominant material used for the gas well casing.
  • the gas well casing is predominantly formed of steel.
  • the at least one portion of softer material is easier to machine than the parts of the gas well casing made of steel.
  • the softer material is a composite material. More preferably the softer material is a fibregiass composite material.
  • each of the at least one portion of softer materia! is located at a predetermined location where it is desirable to form an aperture in the gas well casing. More preferably, each of the at least one portion of softer material is located at a predetermined location where it is desirable to form an aperture in the gas well casing such that a lateral hole can be drilled outwardly from the gas well casing.
  • each of the at least one portion of softer material is a tubular section of softer material.
  • each of the at least one portion of softer material is disposed between sections of the gas well casing formed of steel.
  • the gas well casing may have a section formed of steel attached to a top part of a tubular section of composite material and another section formed of steei attached to the bottom part of the tubular section of composite material.
  • the casing bit forms the desired number of apertures through each of the tubular sections of softer material.
  • one of the upper orientation subassembly or the lower subassembly has an orientation pin and the other of the upper orientation subassembly or the lower subassembly has a slot to receive the orientation pin. More preferably the upper orientation subassembly has the orientation pin and the lower subassembly has the slot to receive the orientation pin.
  • the orientation pin may be of any suitable shape, including rectangular, square, circular and/or the like.
  • one of the upper orientation subassembly or the lower subassembly has a shank from which the orientation pin extends and the other of the upper orientation subassembly or the lower subassembly has a receiving recess in which the slot is formed.
  • the slot may be formed on the shank and the orientation pin may be formed within the receiving recess.
  • the receiving recess is adapted to receive the shank.
  • the receiving recess has a tapered opening. Typicaily the tapered opening aids in locating the shank relative to the receiving recess.
  • the slot is formed such that the orientation pin is initially received in a direction parallel to a longitudinal axis of the receiving recess.
  • the slot is formed such that the orientation pin moves in a radial direction relative to the longitudinal axis of the receiving recess to secure the upper orientation subassembly to the lower orientation subassembly.
  • the slot is "J" shaped, having a longitudinal component and a radial component relative to the longitudinal axis of the receiving recess.
  • the upper orientation subassembly has a shear pin hole.
  • the lower orientation subassembly has a shear pin hole.
  • the shear pin hole of the upper orientation subassembly aligns with the shear pin hole of the lower orientation subassembly when the upper orientation subassembly is in a predetermined orientation relative to the lower orientation subassembly.
  • the orientation assembly further comprises a shear pin that is adapted to be inserted into the shear pin hole of the upper orientation subassembly and the shear pin hole of the lower orientation subassembly when aligned to secure the upper orientation subassembly to the lower orientation subassembly.
  • the shear pin is adapted to shear when a predetermined force is applied to the upper orientation subassembly relative to the lower orientation subassembly.
  • the shear pin may be adapted to shear when a predetermined downward force is applied to the upper orientation subassembly relativ to the lower orientation subassembly.
  • the upper orientation subassembly has an upper coupling adapted to be operativeiy attached to the wedge assembly.
  • the lower subassembly has lower coupling adapted to be operativeiy attached to an anchor.
  • the anchor is secured toward the bottom of the gas well casing.
  • the invention in another form, resides in a gas well assembly, the gas well assembly comprising:
  • a wedge assembly movably located at least partially within the gas well casing.
  • the gas well casing is a steel gas well casing.
  • the gas well casing may be a gas well casing having at least one portion of softer material as described in this specification.
  • the wedge assembly is a wedge assembly as described in this specification.
  • the invention resides in method of forming an aperture in a gas well casing, the method including the steps of:
  • the step of deflecting the casing bit with the wedge assembly, such that the casing bit forms an aperture in the gas well casing involves def lecting the casing bit such that it contacts an inner surface of the gas well casing.
  • the step further includes milling the gas well casing with the casing bit such that an aperture is formed from the inner surface of the gas well casing to an outer surface of the gas well casing. It will be appreciated that in this context, milling can include drilling.
  • a deflection face of the wedge assembly deflects the casing bit.
  • the step of locating a wedge assembly within the gas well casing involves spacing the wedge assembly from the bottom of the gas well casing using a spacer.
  • the step further includes releasably securing the spacer reiative to the bottom of the gas well casing.
  • the step further includes using a direction assembly to set a predetermined radial direction of the wedge assembly relative to the gas well casing.
  • the step of locating a wedge assembly within the gas well casing involves lowering the wedge assembly using a deployment casing.
  • the method includes the step of using a packer to seal an upper part of the wedge assembly from the gas well casing below to prevent drill cuttings from the forming of the aperture from migrating down the gas well casing.
  • the method includes the step of providing the gas well casing with portions of material that is softer than the predominant material used for the gas well casing in the areas where an aperture is to be formed.
  • the softer material is a composite material.
  • the gas well casing is predominantly made of steel and the softer material is a fibregiass composite material.
  • the method may include the step of providing a steel gas well casing.
  • the method includes the step of forming the gas well casing.
  • th step of forming the gas well casing includes the step of providing at least one portion of softer material.
  • the step of providing at least one portion of softer material involves each of the at least one portion of softer material being a tubular section of material, and each of the tubular sections of material being disposed between steel gas well casing sections.
  • the method includes the step of locating the gas well casing in a well.
  • the well is a gas well for coal seam gas, Alternatively, the well may be a gas well for unconventional or conventional gas. Alternatively the well may be a gas well for sequestration of gas or liquids into suitable formations.
  • the step of deflecting the casing bit with the wedge assembly, such that the casing bit forms an aperture in the gas well casing includes the step of forming at least one aperture through each of the at least one portion of softer matenal.
  • the ste of forming at least one aperture through each of the at least one portion of softer material involves using the wedge assembly to deflect the casing bit into each of the at least one portion of softer material.
  • the method includes the step of installing a gas well orientation assembly.
  • the step of installing a gas well orientation assembly includes the steps of providing a gas well orientation assembly having an upper orientation subassembly and a lower orientation subassembly, releasably securing the upper orientation subassembly to the lower orientation subassembly and securing the lower orientation subassembly to a bottom portion of the gas well casing.
  • the step of releasably securing the upper orientation subassembly to the lower orientation subassembly involves receiving an orientation pin of one of the upper orientation subassembly or the lower subassembly into a slot of the other of the upper orientation subassembly or the lower subassembly.
  • the step of releasably securing the upper orientation subassembly to the lower orientation subassembly involves inserting a shear pin into a shear pin hole of the upper orientation subassembly and a shear pin hole of the lower orientation subassembly.
  • the step of securing the lower orientation subassembly to a bottom portion of the gas well casing involves securing the lower orientation subassembly to an anchor.
  • the step further involves securing the anchor to a bottom portion of the gas well casing.
  • the anchor is lowered to a bottom portion of the gas well casing using the gas well orientation assembly and is secured to the gas well casing.
  • the method includes the step of orienting the gas well orientation assembly in a predetermined orientation relative to the gas well casing.
  • the anchor is secured to a bottom portion of the gas well casing once the gas well orientation assembly is oriented in a predetermined orientation relative to the gas well casing.
  • the method includes the step of shearing the shear pin.
  • the step of shearing the shear pin is performed after the lower orientation subassembly is secured to a bottom portion of the gas well casing.
  • the gas well orientation assembly is a gas well orientation assembly as described in this specification,
  • the method in another embodiment, includes the step of forming a gas well.
  • the method includes the step of providing the gas well casing in a well.
  • the well is a vertical well.
  • the method includes the step of drilling a plurality of lateral holes outwardly from the gas well casing.
  • the plurality of lateral holes extend outwardly from at least one aperture in the gas well casing. More preferably the method includes forming at least one aperture in the gas well casing and then drilling a plurality of lateral holes outwardly from the gas well casing, the plurality of lateral holes extending from the at least one aperture in the gas well casing.
  • the method includes the step of drilling at least one branch lateral hole outwardly from at least one of the plurality of lateral holes.
  • a benefit of this is that only one aperture may to be formed for a single lateral hole extending outwardl from the gas well casing and having at least one branch lateral hole extending from the lateral hole (i.e. no additional apertu e needs to be formed in the gas well casing for the at least one branch lateral hole).
  • the plurality of lateral holes extend outwardly from the gas well casing spaced over 360° when viewed in plan view.
  • the plurality of lateral holes may extend outwardly from the gas well casing spaced over substantially 180° or 90° when viewed in plan view. Having the plurality of lateral holes extend outwardly from the gas well casing spaced over substantially 180° or 90° when viewed in plan view ma be beneficial when the gas well casing is located near a boundary. It will be appreciated that the plurality of lateral holes may extend outwardly from the gas well casing spaced over a predetermined angle depending on other factors such as geological formations
  • the ste of providing a gas well casing in a well involves forming the well.
  • the step further includes lowering the gas well casing in the well.
  • the step of drilling a plurality of laterai holes outwardly from the gas well casing involves drilling a plurality of lateral holes such that they diverge from one another.
  • the step of forming a plurality of lateral holes outwardly from the gas well casing involves drilling a plurality of lateral holes such that each hole runs substantially parallel to at least one other lateral hole.
  • the step of forming a plurality of lateral holes outwardly from the gas well casing involves drilling a plurality of lateral holes such that they initially diverge from one another and then run substantially parallel to at least one other lateral hole.
  • the step of forming a plurality of lateral holes outwardly from the gas well casing involves drilling a plurality of lateral holes initially in downwards direction relative to the gas well casing and then transitioning to a direction that is transverse to the gas well casing.
  • the transverse direction is substantially orthogonal to the gas well casing.
  • the transition has a radius in the range of 20 to 40 meters. More preferably the transition has a radius in the range of 25 to 35 meters. Even more preferably, the transition has a radius of approximately 30 meters.
  • FIG 1 shows a schematic sectioned view of a wedge assembly located in a gas well casing
  • FIG 2 shows a schematic cross sectional view of part of a wedge assembly
  • FIG 3 shows a schematic cross sectional view of a wedge assembly located in a gas well casing
  • FIG 4 shows a schematic perspective view of a gas well according to an embodiment of the invention
  • FIG 5 shows a schematic cross sectional view of a gas well
  • FIG 6 shows a schematic cross sectional view of an orientation assembly
  • FIG 7 shows a plan view of prior art vertical well spacing for gas extraction
  • FIG 8 shows a schematic plan view of vertical well spacing for gas extraction according to an embodiment of the invention
  • FIG 9 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • FIG 10 shows a plan view of a well design for gas extraction according to an embodiment of the invention
  • FIG 1 1 shows a schematic plan view of a well design for mine degassing according to an embodiment of the invention
  • FIG 12 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention
  • FIG 13 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention
  • FIG 14 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • FIG 15 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • FIG 16 shows a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • FIG 17 shows a schematic plan view of a lateral hole having branched lateral holes according to an embodiment of the invention.
  • Figure 1 shows a schematic sectioned view of a wedge assembly 100 located in a gas well casing 200
  • the wedge assembly 100 has a wedge 102 having a deflection face 104.
  • the deflection face 104 is adapted to deflect a casing bit (not shown) such that the casing bit can form an aperture 224 in the gas well casing 200.
  • the gas well casing 200 has a 7" (approx. 1 78mm) external diameter.
  • the wedge assembly 100 has a packer 1 12 located near a lower end of the wedge 102, The packer 1 12 isolates and seals the upper part of the wedge assembly 100 from the gas well casing 200 below to prevent drill cuttings (not shown) from the forming of the aperture 224 from migrating down the gas well casing 200.
  • the wedge assembly 100 has a direction assembly 1 14 that can set the direction of the deflection face 104 relative to a spacer.
  • the direction of the deflection face 104 is set by rotating part of the direction assembly 1 14 relative to a spacer 1 16 and locking the direction assembly 1 14 in position once the defleetion face 104 is facing the desired direction. It will be appreciated that changing the direction of the deflection face 104 will change the radial location of where the casing bit (not shown) would form an aperture in the gas well casing 200.
  • the spacer 1 16 is connected to a lower part of the direction assembly 1 14.
  • the length of the spacer 1 16 determines the vertical location of the deflection face 104 in the gas well casing, as the spacer 116 is releasabiy secured relative to the bottom of the gas well casing 200. It will be appreciated that using different length spacers will change the vertical location of where the casing bit (not shown) would form an aperture in the gas well casing 200.
  • the spacer 1 6 is made from one or more lengths of 5.5" (approx 140mm) diameter casing. It will also be appreciated that in an alternative embodiment (not shown), the spacer may also be drill pipe or drill collars.
  • the spacer 116 is radially oriented and releasabiy secured relative to the bottom of the gas well casing 200 by an orientation assembly 400.
  • the orientation assembly 400 has an upper orientation subassembly 420 attached to the spacer 116 and a lower orientation subassembly 440 attached to a mechanical set anchor 260 near the bottom of the gas well casing 200.
  • the orientation assembly 400 will be explained in more detail below with reference to figure 6.
  • the wedge assembly 100 has a deployment casing 1 18 extending from the top end of the wedge 102 to the surface 310 when the wedge assembly 100 is located in the gas well casing 200.
  • the deployment casing 118 is used to lower the wedge assembly 100 into the gas well casing 200.
  • the deployment casing 1 18 is hollow so that a casing bit (not shown) can be lowered through the deployment casing 118 and deflected by the deflection face 104 of the wedge 102.
  • the deployment casing 1 18 also acts as a conduit for driliing fluids (not shown) used in drilling lateral holes such as lateral hole 240. It will be appreciated that a different length deployment casing 118 may be used if the length of the spacer 116 is changed.
  • the deployment casing 118 is made from one or more lengths of 5.5" (approx 140mm) diameter casing that has an internal diameter of 5" (approx. 127mm).
  • the deployment casing 118 has ports 120 located at a predetermined depths. High pressure air is injected through these ports 120 to mingle with the drilling fluid that is returning to the surface to make this fluid lighter and to control the hydrostatic pressure.
  • the hydrostatic pressure can also be adjusted by the number, size and location (e.g. depth) of ports 120.
  • An orientation flange 122 is located at the top of the deployment casing 118 to orientate or check the orientation of the deflection face 104.
  • the wedge assembly 100 has centra!isers 124 located above and below the wedge 102 to ensure that the wedge assembl 100 is held rigidly and centrally within the gas well casing 200.
  • the gas well casing 200 has a steel casing 210 and a section of composite casing in the form of a fibreglass casing 220 in the area where the aperture 224 is to be formed.
  • a casing bit (not shown) does not have to drill through the steel casing 210.
  • Figure 1 schematically shows the fibreglass casing 220, it will be appreciated that the fibreglass casing 220 can be flush with the outside surface of the steel casing 210.
  • the section of composite casing can be a tubular section disposed between two sections of steel casing.
  • the gas well casing 200 has perforations 230 that are positioned adjacent the coal seam 320 to assist in the extraction of gas from the coal seam 320. It will be appreciated that in an alternate embodiment (not shown) the perforations 230 may be omitted, to for example prevent possible ingress of coal fines from a coal seam.
  • a lateral hole 240 is drilled that follows the coal seam 320.
  • the wedge 102 is made from a piece of steel having an external diameter of 5" (approx. 127mm).
  • the wedge 102 is welded into a wedge casing 106.
  • the wedge casing 106 is made from a length of 5.5" (approx 140mm) diameter casing that has an internal diameter of 5" (approx. 127mm).
  • the wedge casing 106 has an opening formed that corresponds to the deflection face 104 of the wedge 102.
  • the deflection face 104 has a concave shape (not shown) to suit a casing bit having a 4.75 N (approx. 1 1 mm) external diameter.
  • An upper coupling 108 is located at the upper end of the wedge casing 106.
  • the upper coupling 108 is a 5.5" BTC Coupling.
  • the upper coupling 108 connects the wedge casing 106 to the deployment casing (118 as seen in figure 1).
  • a lower coupling 110 is located at the lower end of the wedge casing 106.
  • the lower coupling 1 10 connects the wedge casing 106 to the packer (112 as seen in figure 1 ).
  • Figure 3 shows a schematic cross sectional view of part of a wedge assembly 100 located in a gas well casing 200.
  • the spacer 1 16 is of a predetermined length and the direction assembly 114 is set to a predetermined angle such that the deflection face 104 of the wedge 102 is orientated to deflect a casing bit (not shown) into the top right aperture 224 and lateral hole 240.
  • the Packer 1 12 prevents excess drill cuttings from migrating to the gas well casing 200 below.
  • the upper apertures 224 and lateral holes 240 are staggered to avoid excess weakening of the gas well casing 200.
  • FIG. 4 shows a schematic perspective view
  • Figure 5 shows a schematic cross sectional view
  • the gas well 10 has a well head 12 attached to the top of the gas well casing 200 near the surface 310.
  • Lateral drill holes 240 are drilled outwards from apertures 224 in the gas well casing 200.
  • the lateral drill holes 240 initially have a "short" radius of approximately 30 meters and then follow the coal seams 320.
  • a production string 14 is located in the gas well casing 200 and a progressive cavity pump 16 is located at the bottom of the production string.
  • FIG 6 there is shown a schematic cross sectional view of an orientation assembly 400.
  • the orientation assembly 400 has an upper orientation subassembly 420 that can be reieasably secured to a lower orientation subassembly 440.
  • the upper orientation subassembly 420 has an upper coupling 424 that connects to a spacer (116 as seen in figure 1).
  • the upper orientation subassembly 420 has a shank 426 that can be received by a receiving recess 442 of the lower orientation subassembly 440.
  • the shank 426 has a shear pin hole 428 to receive a shear pin ⁇ not shown) which can secure the upper orientation subassembly 420 to the lower orientation subassembly 440.
  • the shank 426 also has an orientation pin 422, which can be received into a "J" Slot 444 in the receiving recess 442 of the lowe orientation subassembly 440.
  • the orientation pin 422 and the slot 444 ensure that the upper orientation subassembly 420 can only be received by the lower orientation subassembly 440 in a predetermined orientation.
  • the lower orientation subassembly 440 has a tapering opening 446 to assist in guiding the shank 426 of the upper orientation subassembly 420 into the receiving recess 442.
  • the lower orientation subassembly 440 has a shear pin hole 448, which aligns with the shear pin hole 428 of the upper orientation subassembly 420 when the orientation pin 422 is located in the bottom left part of the "J" slot 444.
  • the lower orientation subassembly has a lower coupling 450 that secures to a packer or a mechanical set anchor (260 as seen in figure 1 ) secured to a bottom section of the gas well casing (200 as seen in figure 1 ).
  • the packer or mechanical set anchor (not shown) is usually secured i the bottom of the gas well casing (not shown) by rotation or a downward force.
  • the shank 426 of the upper orientation subassembly 420 is inserted into the receiving recess 442 of the lower orientation subassembly 440 such that the orientation pin 422 slides to the bottom of the "J" slot, the upper orientation subassembly 420 is then rotated relative to the lower orientation subassembly such that the orientation pin is located at the left end of the "J" slot 444, In this position, the shear pin holes 428 and 448 align and a shear pin (not shown) can b inserted into the holes 428,448 to secure the upper orientation subassembly 420 to the lower orientation subassembly 440,
  • the lower orientation subassembly 440 is connected to an anchor (not shown), the wedge assembly (100, see figure 1 ) is then lowered into a gas well casing (not shown).
  • the anchor (not shown) is set.
  • the shear pin (not shown) can then be sheared by providing the upper orientation subassembly 420 with a downward force relative to the lower orientation subassembly 440.
  • the upper orientation subassembly 420 can then be rotated relative to the lower orientation Subassembly 440 such that the orientation pin 422 is in line with the vertical part of the "J ,! slot 444.
  • the upper orientation subassembly 420 can then be removed from the lower orientation subassembly 440,
  • the lower orientation subassembly 440 remains at the bottom of the gas well casing (not shown) to act as an orientation reference point, if a lateral hole (not shown) should fail, the lower orientation subassembly 440 can be used as a reference point to orient the wedge assembly (100, see figure 1) such that the lateral hole (not shown) can be re-drilled.
  • FIG 7 there is shown a plan view of prior art vertical well spacing for gas extraction.
  • the vertical wells 500 are spaced 500m apart in the Y direction and 1000m apart in the X direction.
  • the vertical wells 500 have a horizontal component 510 that runs for approximately 1000m along a coal seam.
  • the horizontal component 510 is either a surface to inseam lateral hole that is drilled from the surface, remote from the vertical well 500, to intersect the vertical well 500, o , alternatively, the horizontal component 500 is a single continuation of the vertical well 500 which turns a large radius to continue horizontally along the coal seam.
  • Figure 8 shows a schematic plan view of vertical well spacing for gas extraction according to an embodiment of the invention.
  • the vertical portions of the gas wells 10 are spaced 500m apart in the Y direction and 1000m apart in the X direction.
  • Lateral holes 240 are drilled outwardly from the vertical portions of the gas wells 10.
  • lateral holes 240 on the left sides of the gas wells 10 diverge from each other and then run parallel to each other.
  • the lateral holes 240 on the right sides of the gas wells 10 diverge from each other and then run parallel to each other.
  • Such well spacing and lateral hole drilling results in much earlier peak gas production compared to the prior art well placements with the same number of vertical drilling placements.
  • the direction of lateral holes (while they are being drilled) is easier to control over shorter distances ⁇ eg 5Q0m compared to 1000m).
  • the risk of not intersecting a vertical well, which is present when drilling a surface to inseam lateral hole that intersect the vertical well is also eliminated.
  • the lateral holes 240 are drilled outwardly from the vertical well 10.
  • the lateral holes 240 diverge from one another from the vertical well 10 to approximately 70-150m left or right of the vertical well. After this, the lateral holes 240 run parallel for approximately 400m. Having 4 lateral holes 240 reduces the risk of production failure if a single lateral hole 240 fails.
  • FIG 11 there is shown a schematic plan view of a well design for mine degassing according to an embodiment of the invention.
  • vertical wells 10 are drilled down through the longwall 32 that is to be degassed
  • lateral holes 240 are drilled outwardly from the vertical wells 10.
  • the lateral holes extend outwardly in an "X" shaped formation.
  • FIG. 12 With reference to figures 12 and 13 there is shown a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • a vertical well 10 (including a gas well casing) has lateral holes 240 extending from apertures in the gas well casing (not shown).
  • Figure 12 shows 5 lateral holes 240 extending outwardly, spaced over 180° and figure
  • FIG. 13 shows 9 lateral holes 240 extending outwardly, spaced over 180°.
  • a vertical well 10 (including a gas well casing) has lateral holes 240 extending from apertures in the gas well casing (not shown). Branch lateral holes 242 extend outwardly from the lateral holes 240.
  • FIG. 15 With reference to figures 15 and 16 there is shown a schematic plan view of a well design for gas extraction according to an embodiment of the invention.
  • a vertical well 10 (including a gas well casing) has lateral holes 240 extending f om apertures in the gas well casing (not shown).
  • the lateral holes 240 extending outwardly, spaced over 360°.
  • Figure 15 shows branch lateral holes 242 extending outwardly from the lateral holes.
  • FIG 17 With reference to figure 17 there is shown a schematic plan view of a lateral hole 240 having branched lateral holes 242 according to an embodiment of the invention.
  • the lateral hole 240 extends from a gas " well ⁇ not shown).
  • Each branched lateral hole 242 extends from the lateral hole 240.
  • the branched lateraE holes 242 alternately extend from opposed sides of the lateral hole 240 to form a "herringbone" pattern.

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  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Earth Drilling (AREA)

Abstract

Cette invention concerne un ensemble coin pour tubage de sondage à gaz, ledit ensemble coin comprenant un coin présentant une face de déviation conçue pour dévier un outil de tubage et un tubage creux de déploiement conçu pour faire descendre le coin dans le tubage de sondage à gaz. Ledit tubage de déploiement comprend une pluralité d'orifices conçus pour admettre de l'air à haute pression injecté à travers ceux-ci afin d'assister la montée du fluide de forage vers une partie supérieure du tubage de sondage à gaz.
PCT/AU2014/050275 2013-10-09 2014-10-09 Ensemble coin et procédé WO2015051414A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2013903884 2013-10-09
AU2013903884A AU2013903884A0 (en) 2013-10-09 A drilling apparatus and method

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WO2015051414A1 true WO2015051414A1 (fr) 2015-04-16

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5435400A (en) * 1994-05-25 1995-07-25 Atlantic Richfield Company Lateral well drilling
US5735350A (en) * 1994-08-26 1998-04-07 Halliburton Energy Services, Inc. Methods and systems for subterranean multilateral well drilling and completion
GB2361257A (en) * 2000-03-28 2001-10-17 Halliburton Energy Serv Inc Methods and associated apparatus for drilling and completing a wellbore junction
US6923274B2 (en) * 2003-01-02 2005-08-02 Weatherford/Lamb, Inc. Retrievable pre-milled window with deflector
US20060180351A1 (en) * 2005-02-11 2006-08-17 Anthony Paul G Air injection collar
WO2013001512A2 (fr) * 2011-06-30 2013-01-03 Schlumberger Technology B.V. Injection de gaz pour forage à pression gérée

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5435400A (en) * 1994-05-25 1995-07-25 Atlantic Richfield Company Lateral well drilling
US5435400B1 (en) * 1994-05-25 1999-06-01 Atlantic Richfield Co Lateral well drilling
US5735350A (en) * 1994-08-26 1998-04-07 Halliburton Energy Services, Inc. Methods and systems for subterranean multilateral well drilling and completion
GB2361257A (en) * 2000-03-28 2001-10-17 Halliburton Energy Serv Inc Methods and associated apparatus for drilling and completing a wellbore junction
US6923274B2 (en) * 2003-01-02 2005-08-02 Weatherford/Lamb, Inc. Retrievable pre-milled window with deflector
US20060180351A1 (en) * 2005-02-11 2006-08-17 Anthony Paul G Air injection collar
WO2013001512A2 (fr) * 2011-06-30 2013-01-03 Schlumberger Technology B.V. Injection de gaz pour forage à pression gérée

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