CA2495985C - System and method for subterranean access - Google Patents
System and method for subterranean access Download PDFInfo
- Publication number
- CA2495985C CA2495985C CA002495985A CA2495985A CA2495985C CA 2495985 C CA2495985 C CA 2495985C CA 002495985 A CA002495985 A CA 002495985A CA 2495985 A CA2495985 A CA 2495985A CA 2495985 C CA2495985 C CA 2495985C
- Authority
- CA
- Canada
- Prior art keywords
- well bore
- entry
- slanted
- well
- subterranean zone
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims description 35
- 238000005553 drilling Methods 0.000 claims abstract description 18
- 235000009967 Erodium cicutarium Nutrition 0.000 claims description 4
- 239000007789 gas Substances 0.000 description 27
- 239000003245 coal Substances 0.000 description 26
- 239000007788 liquid Substances 0.000 description 17
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 16
- 238000004519 manufacturing process Methods 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 230000008901 benefit Effects 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 5
- 239000012530 fluid Substances 0.000 description 5
- 238000005755 formation reaction Methods 0.000 description 5
- 239000003381 stabilizer Substances 0.000 description 5
- 230000002706 hydrostatic effect Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 239000004568 cement Substances 0.000 description 2
- 239000013505 freshwater Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000012876 topography Methods 0.000 description 1
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
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/14—Obtaining from a multiple-zone well
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geochemistry & Mineralogy (AREA)
- Fluid Mechanics (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Earth Drilling (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
Abstract
A system for accessing a subterranean zone from the surface includes a first, second and third entry well bore extending from the surface, the first, second and third entry well bores (15) located on the same drilling pad (92) at the surface. A slanted well bore (20) extends from each of the entry well bores to the subterranean zone (22). A substantially horizontal drainage pattern extends from the slanted well bores into the subterranean zone.
Description
SYSTEM AND METHOD FOR SUBTERRANEAN ACCESS
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to systems and methods for the recovery of subterranean resources and, more particularly, to a system and method for subterranean access.
BACKGROUND OF THE INVENTION
Subterranean deposits of coal contain substantial quantities of entrained methane gas.. Limited production and use of methane gas from coal deposits has occurred for many years. Substantial obstacles, however, have frustrated more extensive development and use of methane gas deposits in coal seams. The foremost problem in producing methane gas from coal seams is that while coal seams may extend over large areas of up to several thousand acres, the coal seams are fairly thin, varying from a few inches to several meters. Vertical wells drilled into the coal deposits for obtaining methane gas can only drain a fairly small radius around the coal deposits. Further, coal deposits are not amenable to pressure fracturing and other methods often used for increasing methane gas production from rock formations.
As a result, once the gas easily drained from a vertical well bore in a coal seam is produced, further production is limited in volume. Additionally, coal seams are often associated with subterranean water, which must be drained from the coal seam in order to produce the methane.
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to systems and methods for the recovery of subterranean resources and, more particularly, to a system and method for subterranean access.
BACKGROUND OF THE INVENTION
Subterranean deposits of coal contain substantial quantities of entrained methane gas.. Limited production and use of methane gas from coal deposits has occurred for many years. Substantial obstacles, however, have frustrated more extensive development and use of methane gas deposits in coal seams. The foremost problem in producing methane gas from coal seams is that while coal seams may extend over large areas of up to several thousand acres, the coal seams are fairly thin, varying from a few inches to several meters. Vertical wells drilled into the coal deposits for obtaining methane gas can only drain a fairly small radius around the coal deposits. Further, coal deposits are not amenable to pressure fracturing and other methods often used for increasing methane gas production from rock formations.
As a result, once the gas easily drained from a vertical well bore in a coal seam is produced, further production is limited in volume. Additionally, coal seams are often associated with subterranean water, which must be drained from the coal seam in order to produce the methane.
Horizontal drilling patterns have been tried in order to extend the amount of coal seams exposed to a drill bore for gas extraction. Such horizontal drilling techniques, however, require the use of a radiused well bore which presents difficulties in removing the entrained water from the coal seam. The most efficient method for pumping water from a subterranean well, a sucker rod pump, does not work well in horizontal or short radiused bores.
A single slanted well bore allows for effective water removal via a sucker rod pump, capturing a benefit of a horizontal well system, without limiting the use of horizontal drainage patterns in the target zone.
SUMMARY OF THE INVENTION
The present invention provides a slant entry well system and method for accessing a subterranean zone from the surface that substantially eliminate or reduce the disadvantages and problems associated with previous systems and methods. In particular, certain embodiments of the present invention provide a slant entry well system and method for efficiently producing and removing entrained methane gas and water from a coal seam without requiring excessive use of radiused or articulated well bores or large surface area in which to conduct drilling operations.
In accordance with one embodiment of the present invention, a system for accessing a subterranean zone from the surface includes a first, second, and third entry well bore extending from the surface, the first, second, and third entry well bores located no more than one thousand feet away from each other at the surface. A
A single slanted well bore allows for effective water removal via a sucker rod pump, capturing a benefit of a horizontal well system, without limiting the use of horizontal drainage patterns in the target zone.
SUMMARY OF THE INVENTION
The present invention provides a slant entry well system and method for accessing a subterranean zone from the surface that substantially eliminate or reduce the disadvantages and problems associated with previous systems and methods. In particular, certain embodiments of the present invention provide a slant entry well system and method for efficiently producing and removing entrained methane gas and water from a coal seam without requiring excessive use of radiused or articulated well bores or large surface area in which to conduct drilling operations.
In accordance with one embodiment of the present invention, a system for accessing a subterranean zone from the surface includes a first, second, and third entry well bore extending from the surface, the first, second, and third entry well bores located no more than one thousand feet away from each other at the surface. A
slanted well bore extends from each of the first and second entry well bores to the subterranean zone. A
substantially horizontal drainage pattern extends from the slanted well bores into the subterranean zone.
According to another embodiment of the present invention, a method for accessing a subterranean zone from the surface includes forming three or more closely spaced entry well bores and forming a plurality of slanted well bores from the entry well bores to the subterranean zone. The method also includes forming drainage patterns from the slanted well bores into the subterranean zone and enlarged cavities in the slanted well bores.
Embodiments of the present invention may provide one or more technical advantages. These technical advantages may include the formation of three or more closely spaced entry well bores, a plurality of slanted well bores, and drainage patterns to optimize the area of a subsurface formation which may be drained of gas and liquid resources. This allows for more efficient drilling and production and greatly reduces costs and problems associated with other systems and methods. Another technical advantage includes providing a method for accessing a subterranean zone from the surface using a plurality of slanted well bores with one or more enlarged cavities. The enlarged cavities allow for reduction of velocity of gases escaping through the slanted well bores, aiding in the removal of entrained liquids and optimizing the removal of resources from the subterranean zone.
substantially horizontal drainage pattern extends from the slanted well bores into the subterranean zone.
According to another embodiment of the present invention, a method for accessing a subterranean zone from the surface includes forming three or more closely spaced entry well bores and forming a plurality of slanted well bores from the entry well bores to the subterranean zone. The method also includes forming drainage patterns from the slanted well bores into the subterranean zone and enlarged cavities in the slanted well bores.
Embodiments of the present invention may provide one or more technical advantages. These technical advantages may include the formation of three or more closely spaced entry well bores, a plurality of slanted well bores, and drainage patterns to optimize the area of a subsurface formation which may be drained of gas and liquid resources. This allows for more efficient drilling and production and greatly reduces costs and problems associated with other systems and methods. Another technical advantage includes providing a method for accessing a subterranean zone from the surface using a plurality of slanted well bores with one or more enlarged cavities. The enlarged cavities allow for reduction of velocity of gases escaping through the slanted well bores, aiding in the removal of entrained liquids and optimizing the removal of resources from the subterranean zone.
Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions, 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, wherein like numerals represent like parts, in which:
FIGURE 1 illustrates an example slant well system for production of resources from a subterranean zone;
FIGURE 2A illustrates a vertical well system for production of resources from a subterranean zone;
FIGURE 2B illustrates a portion of an example slant entry well system in further detail;
FIGURE 3 illustrates an example method for producing water and gas from a subsurface formation;
FIGURE 4 illustrates an example entry well bore ;
FIGURE 5 illustrates the use of an example system of an entry well bore and a slanted well bore;
FIGURE 6 illustrates an example system of an entry well bore and a slanted well bore;
FIGURE 7 illustrates an example system of a slanted well bore and an articulated well bore;
FIGURE 8 illustrates production of water and gas in an example slant well system; and FIGURE 9 illustrates an example drainage pattern for use with a slant well system.
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, wherein like numerals represent like parts, in which:
FIGURE 1 illustrates an example slant well system for production of resources from a subterranean zone;
FIGURE 2A illustrates a vertical well system for production of resources from a subterranean zone;
FIGURE 2B illustrates a portion of an example slant entry well system in further detail;
FIGURE 3 illustrates an example method for producing water and gas from a subsurface formation;
FIGURE 4 illustrates an example entry well bore ;
FIGURE 5 illustrates the use of an example system of an entry well bore and a slanted well bore;
FIGURE 6 illustrates an example system of an entry well bore and a slanted well bore;
FIGURE 7 illustrates an example system of a slanted well bore and an articulated well bore;
FIGURE 8 illustrates production of water and gas in an example slant well system; and FIGURE 9 illustrates an example drainage pattern for use with a slant well system.
DETAILED DESCRIPTION OF THE INVENTION
FIGURE 1 illustrates an example slant well system for accessing a subterranean zone from the surface. In the embodiment described below, the subterranean zone is 5 a coal seam. It will be understood that other subterranean formations and/or zones can be similarly accessed using the slant well system of the present invention to remove and/or produce water, hydrocarbons, and other fluids in the zone, to treat minerals in the zone prior to mining operations, to inject or introduce fluids, gases, or other substances into the zone or for any other appropriate purpose.
Referring to FIGURE l, a slant well system 10 includes entry well bores 15, slant wells 20, articulated well bores 24, cavities 26, and rat holes 27. Entry well bores 15 extend from the surface 11 towards the subterranean zone 22. Slant wells 20 extend from the terminus of each entry well bore 15 to the subterranean zone 22, although slant wells 20 may alternatively extend from any other suitable portion of an entry well bore 15.
As used herein, "each" means all of a particular subset.
Where there are multiple subterranean zones 22 at varying depths, as in the illustrated example, slant wells 20 extend through the subterranean zones 22 closest to the surface into and through the deepest subterranean zone 22. Articulated well bores 24 may extend from each slant well 20 into each subterranean zone 22. One or more cavities 26 may be located along a slant well 20 and a cavity 26 or a rat hole 27 may be located at the terminus of each slant well 20.
In FIGURES 1, and, 4-8, entry well bores 15 are illustrated as being substantially vertical; however, it should be understood that entry well bores 15 may be formed at any suitable angle relative to the surface 11 to accommodate, for example, surface geometries and attitudes and/or the geometric configuration or attitude of a subterranean resource. In the illustrated embodiment, each slant well 20 is formed to angle away from entry well bore 15 at an angle designated a, which in the illustrated embodiment is approximately 20 degrees. It will be understood that each slant well 20 may be formed at other angles to accommodate surface topologies and other factors similar to those affecting entry well bores 15. In the illustrated embodiment, slant wells 20 are formed in relation to each other at an angular separation of approximately sixty degrees. It will be understood that slant wells 20 may be separated by other angles depending likewise on the topology and geography of the area and location of the target coal seam 22.
Entry well bores 15 are formed at the surface at a distance of (3 feet apart. In the illustrated embodiment, entry well bores 15 are approximately twenty feet apart.
It will be understood that entry well bores 15 may be formed at other separations to accommodate surface topologies and/or the geometric configuration or attitude of a subterranean resource.
In some embodiments, entry well bores 15 may be between two feet and one hundred feet apart. In some embodiments, the entry well bores 15 may be located on the same drilling pad. As used herein, "on the same drilling pad" means located at the same drilling location where drilling operations are being conducted. In some embodiments, entry well bores 15 are closely spaced together. As used herein, "closely spaced" means on the same drilling pad.
Cavities 26 may be formed at intervals along slant wells 20 above one or more of articulated well bores 24.
For example, cavities 26 may be formed immediately above an articulated well bore 24. Cavities 26 may also be formed proximate to the junction of slant well 20 and articulated well bore 24. As used herein, proximate means immediately above, below, or at the junction of slant well 20 and articulated well bore 24. It will be understood that other appropriate spacing may also be employed to accommodate, for example, sub-surface geometries and attitudes and/or the geometric configuration or attitude of a subterranean resource.
Slant well 20 may also include a cavity 26 and/or a rat hole 27 located at the terminus of each slant well 20.
Slant wells 20 may include one, both, or neither of cavity 26 and rat hole 27.
FIGURES 2A and 2B illustrate by comparison the advantage of forming slant wells 20 at an angle off the vertical. Referring to FIGURE 2A, a vertical well bore is shown with. an articulated well bore 32 extending into a coal seam 22. As shown by the illustration, fluids drained from coal seam 22 into articulated well 25 bore 32 must travel along articulated well bore 32 upwards towards vertical well bore 30, a distance of approximately W feet before they may be collected in vertical well bore 30. This distance of W feet is known as the hydrostatic head and must be overcome before the 30 fluids may be collected from vertical well bore 30.
Referring now to FIGURE 2B, a slant entry well 34 is shown with an articulated well bore 36 extending into coal seam 22. Slant entry well 34 is shown at an angle a away from the vertical. As illustrated, fluids collected from coal seam 22 must travel along articulated well bore 36 up to slant entry well 34, a distance of W' feet.
Thus, the hydrostatic head of a slant entry well system is reduced as compared to a substantially vertical system. Furthermore, by forming slant entry well 34 at angle a, the articulated well bore 36 drilled from tangent or kick off point 38 has a greater radius of curvature than articulated well bore 32 associated with vertical well bore 30. This allows for articulated well bore 36 to be longer than articulated well bore 32 (since the friction of a drill string against the radiused portion is reduced), thereby penetrating further into coal seam 22 and draining more of the subterranean zone.
FIGURE 3 illustrates an example method of forming a slant entry well 20. The steps of FIGURE 3 will be further illustrated in subsequent FIGURES 4-8. The method begins at step 100 wherein an entry well bore is formed. At step 105, a fresh water casing or other suitable casing is installed into the entry well bore formed at step 100. At step 110, the fresh water casing is cemented in place inside the entry well bore of step 100.
At step 115, a drill string is inserted through the entry well bore, and is used to drill approximately fifty feet past the casing. In some embodiments, a short, radiused bore is formed. In some embodiments, the radiused bore may be two hundred feet long and articulate thirty-five degrees over its length. It will be understood that other lengths and degrees may be employed based on the local geology and topography. At step 120, the drill is oriented to the desired angle of the slant well and, at step 125, a slant well bore is drilled down into and through the target subterranean zone. At step 130, one or more cavities are formed in the slant well.
At step 135 the slant well casing is installed.
Next, at step 140, a short radius curve is drilled into the target coal seam. Next, at step 145, a substantially horizontal well bore is drilled into and along the coal seam. It will be understood that the substantially horizontal well bore may depart from a horizontal orientation to account for changes in the orientation of the coal seam. Next, at step 150, a drainage pattern is drilled into the coal seam through the substantially horizontal well. The drainage pattern may comprise a pinnate pattern, a crow's foot pattern, or other suitable pattern. At decisional step 155, a determination is made whether additional subterranean zones are to be drained as, for example, when multiple subterranean zones are present at varying depths below the surface. If additional subterranean zones are to be drained, the process repeats steps 140 through 155 for each additional subterranean zone. If no further subterranean zones are to be drained, the process continues to step 160.
At decisional step 160, a determination is made whether additional slant wells are required. If additional slant wells are required, the process returns along the Yes branch to step 100 and repeats through step 155. A separate entry well bore may be formed for each individual slant well bore. Thus, for each slant well, the process begins at step 100, wherein a substantially vertical well bore is found. In some embodiments, however, multiple slant wells may be formed from one entry well bore.
If no additional slant wells are required, the process continues along the No branch to step 165.
5 At step 165, production equipment is installed into each slant well and at step 170 the process ends with the production of water and gas from the subterranean zone.
Although the steps have been described in a certain order, it will be understood that they may be performed l0 in any other appropriate order. Furthermore, one or more steps may be omitted, or additional steps performed, as appropriate.
For example, where multiple target zones are present (as determined at step 155), an enlarged diameter cavity may be found (step 130) above each target zone before any of the short radius curves are drilled (step 140).
Alternatively, all of the short radius curves may be found in each target zone (step 140) before any enlarged diameter cavities are found (step 130). Other suitable modifications will be apparent to one skilled in the art.
FIGURE 4 illustrates entry well bore 15 and casing 44 in its operative mode as a slant well 20 is about to be drilled. Corresponding with step 110 of FIGURE 3, a cement retainer 46 is poured or otherwise installed around the casing inside entry well bore 15. The cement casing may be any mixture or substance suitable to maintain casing 44 in the desired position with respect to entry well bore 15. A drill string 50 is positioned to begin forming a slant well. In order to keep drill string 50 relatively centered in casing 44, a stabilizer 52 may be employed. Stabilizer 52 may be a ring and fin type stabilizer or any other stabilizer suitable to keep drill string 50 relatively centered. To keep stabilizer 52 at a desired depth in well bore 15, stop ring 53 may be employed. Stop ring 53 may be constructed of rubber or metal or any other suitable down-hole environment material.
FIGURE 5 illustrates an example system of a slant well 20. Corresponding with step 115 of FIGURE 3, well bore 60 is drilled approximately fifty feet past the end of entry well bore 15 (although any other appropriate distance may be drilled). Well bore 60 is drilled away from casing 44 in order to minimize magnetic interference and improve the ability of the drilling crew to guide the drill bit in the desired direction. As described above in conjunction with FIGURE 3, well bore 60 may also comprise an articulated well bore with a radius of thirty-five degrees in two hundred feet.
Corresponding with step 120 of FIGURE 3, the drill bit is oriented in preparation for drilling slant entry well bore 64. Corresponding with step 125 of FIGURE 3, a slant entry well bore 64 is drilled from the end of the radius well bore 62 into and through. the subterranean zone 22. Alternatively, slant well 20 may be drilled directly from entry well bore 15, without including tangent well bore 60 or radiused well bore. A rat hole 66, which is an extension of slant well 64, is also formed. Rat hole 66 may also be an enlarged diameter cavity or other suitable structure. Corresponding with step 130 of FIGURE 3, a cavity 26 is formed in slant well 64 .
Cavity 26 acts as a velocity reduction chamber, separating entrained liquids from gasses destined for the surface. Without at least one cavity 26 located closer to the surface than the shallowest lateral well bore, entrained liquids form a mist that raises down-hole pressure. Friction is increased by the liquids entrained in escaping gasses, creating increased back pressure (down-hole pressure). Reducing the gas velocity separates out the liquid as the velocity drops below the speed at which the gas can entrain liquids. Cavity 26 lowers the velocity of the gas enough to separate out the entrained liquids, allowing the gas to proceed to the surface more efficiently.
In the illustrated embodiment, cavity 26 is shown immediately above the expected kick-off point for a subsequent short radiused well bore. It will be understood that cavity 26 may be otherwise suitably located. Moreover, it will be understood that cavity 26 may also be formed after the horizontal drainage pattern is formed.
FIGURE 6 is an illustration of the positioning of the casing in a slant well 64. For ease of illustration, only one slant well 64 is shown. Corresponding with step 135 of FIGURE 3, a whipstock casing 70 is installed into the slant entry well bore 64. In the illustrated embodiment, whipstock casing 70 includes a whipstock 72 which is used to mechanically direct a drill string into a desired orientation. It will be understood that other suitable techniques may be employed and the use of a whipstock 72 is not necessary when other suitable methods of orienting a drill bit through slant well 64 into the subterranean zone 22 are used. Whipstock casing 70 is oriented such that whipstock 72 is positioned so that a subsequent drill bit is aligned to drill into the subterranean zone 22 at a desired depth.
FIGURE 7 illustrates whipstock casing 70 and slant entry well bore 64 in further detail. As discussed in conjunction with FIGURE 6, whipstock casing 70 is positioned within slant entry well bore 64 such that a drill string 50 will be oriented to pass through slant entry well bore 64 at a desired tangent or kick off point 38. This corresponds with step 140 of FIGURE 3. Drill string 50 is used to drill through slant entry well bore 64 at tangent or kick off point 38 to form articulated well bore 36. In a particular embodiment, articulated well bore 36 has a radius of approximately seventy-one feet and a curvature of approximately eighty degrees per one hundred feet. In the same embodiment, slant entry well 64 is angled away from the vertical at approximately ten degrees. In this embodiment, the hydrostatic head generated in conjunction with production is roughly thirty feet. However, it should be understood that any other appropriate radius, curvature, and slant angle may be used.
FIGURE 8 illustrates a slant entry well 64 and articulated well bore 36 after drill string 50 has been used to form articulated well bore 36. In a particular embodiment, a horizontal well and drainage pattern may then be formed in subterranean zone 22, as represented by step 145 and step 150 of FIGURE 3.
Referring to FIGURE 8, whipstock casing 70 is set on the bottom of rat hole 66 to prepare for production of oil and gas. A sealer ring 74 may be used around the whipstock casing 70 to prevent gas produced from articulated well bore 36 from escaping outside whipstock casing 70. Gas ports 76 allow escaping gas to enter into and up through whipstock casing 70 for collection at the surface. As described above, liquids entrained in the escaping gas may be separated from the gas in enlarged diameter cavities 26 situated above the articulated well bore 36. As the liquids separate from the gas, the liquids travel down slant well 64 and are collected in rat hole 66. Rat hole 66 may also comprise an enlarged diameter cavity (not shown) to Collect liquids arriving from above.
A pump string 78 and submersible pump 80 is used to remove water and other liquids that are collected from the subterranean zone through articulated well bore 36.
As shown in FIGURE 9, the liquids, under the power of gravity and the pressure in subterranean zone 22, pass through articulated well bore 36 and down slant entry well bore 64 into rat hole 66. From there the liquids travel into the opening in the whipstock 72 of whipstock casing 70 where they come in contact with the installed pump string 78 and submersible pump 80. Submersible pump 80 may be a variety of submersible pumps suitable for use in a down-hole environment to remove liquids and pump them to the surface through pump string 78. Installation of pump string 78 and submersible pump 80 corresponds with step 165 of FIGURE 3. Production of liquid and gas corresponds with step 170 of FIGURE 3.
FIGURE 9 illustrates an example drainage pattern 90 that may be drilled from articulated well bores 36. At the center of drainage pattern 90 is a plurality of entry well bores 15 on a drilling pad 92 at the surface. In one embodiment, entry well bores 15 are spaced approximately twenty feet apart. It will be understood that other suitable spacings may also be employed.
Connecting to each entry well bore 15 is a slant well 20. At the terminus of slant well 20, as described above, are substantially horizontal well bores 94 roughly forming a "crow's foot" pattern off of each of the slant 5 wells 20. It will be understood that any other suitable drainage patterns, for example, a pinnate pattern, may be used. In an example embodiment, the horizontal reach of each substantially horizontal well bore 94 is approximately three hundred feet. Additionally, the 10 lateral spacing between the parallel substantially horizontal well bores 94 is approximately eight hundred feet. ,In this particular embodiment, a drainage area of approximately six hundred and forty acres would result.
Although the present invention has been described 15 with several embodiments, various changes and modifications may be suggested to one skilled in the art.
It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
FIGURE 1 illustrates an example slant well system for accessing a subterranean zone from the surface. In the embodiment described below, the subterranean zone is 5 a coal seam. It will be understood that other subterranean formations and/or zones can be similarly accessed using the slant well system of the present invention to remove and/or produce water, hydrocarbons, and other fluids in the zone, to treat minerals in the zone prior to mining operations, to inject or introduce fluids, gases, or other substances into the zone or for any other appropriate purpose.
Referring to FIGURE l, a slant well system 10 includes entry well bores 15, slant wells 20, articulated well bores 24, cavities 26, and rat holes 27. Entry well bores 15 extend from the surface 11 towards the subterranean zone 22. Slant wells 20 extend from the terminus of each entry well bore 15 to the subterranean zone 22, although slant wells 20 may alternatively extend from any other suitable portion of an entry well bore 15.
As used herein, "each" means all of a particular subset.
Where there are multiple subterranean zones 22 at varying depths, as in the illustrated example, slant wells 20 extend through the subterranean zones 22 closest to the surface into and through the deepest subterranean zone 22. Articulated well bores 24 may extend from each slant well 20 into each subterranean zone 22. One or more cavities 26 may be located along a slant well 20 and a cavity 26 or a rat hole 27 may be located at the terminus of each slant well 20.
In FIGURES 1, and, 4-8, entry well bores 15 are illustrated as being substantially vertical; however, it should be understood that entry well bores 15 may be formed at any suitable angle relative to the surface 11 to accommodate, for example, surface geometries and attitudes and/or the geometric configuration or attitude of a subterranean resource. In the illustrated embodiment, each slant well 20 is formed to angle away from entry well bore 15 at an angle designated a, which in the illustrated embodiment is approximately 20 degrees. It will be understood that each slant well 20 may be formed at other angles to accommodate surface topologies and other factors similar to those affecting entry well bores 15. In the illustrated embodiment, slant wells 20 are formed in relation to each other at an angular separation of approximately sixty degrees. It will be understood that slant wells 20 may be separated by other angles depending likewise on the topology and geography of the area and location of the target coal seam 22.
Entry well bores 15 are formed at the surface at a distance of (3 feet apart. In the illustrated embodiment, entry well bores 15 are approximately twenty feet apart.
It will be understood that entry well bores 15 may be formed at other separations to accommodate surface topologies and/or the geometric configuration or attitude of a subterranean resource.
In some embodiments, entry well bores 15 may be between two feet and one hundred feet apart. In some embodiments, the entry well bores 15 may be located on the same drilling pad. As used herein, "on the same drilling pad" means located at the same drilling location where drilling operations are being conducted. In some embodiments, entry well bores 15 are closely spaced together. As used herein, "closely spaced" means on the same drilling pad.
Cavities 26 may be formed at intervals along slant wells 20 above one or more of articulated well bores 24.
For example, cavities 26 may be formed immediately above an articulated well bore 24. Cavities 26 may also be formed proximate to the junction of slant well 20 and articulated well bore 24. As used herein, proximate means immediately above, below, or at the junction of slant well 20 and articulated well bore 24. It will be understood that other appropriate spacing may also be employed to accommodate, for example, sub-surface geometries and attitudes and/or the geometric configuration or attitude of a subterranean resource.
Slant well 20 may also include a cavity 26 and/or a rat hole 27 located at the terminus of each slant well 20.
Slant wells 20 may include one, both, or neither of cavity 26 and rat hole 27.
FIGURES 2A and 2B illustrate by comparison the advantage of forming slant wells 20 at an angle off the vertical. Referring to FIGURE 2A, a vertical well bore is shown with. an articulated well bore 32 extending into a coal seam 22. As shown by the illustration, fluids drained from coal seam 22 into articulated well 25 bore 32 must travel along articulated well bore 32 upwards towards vertical well bore 30, a distance of approximately W feet before they may be collected in vertical well bore 30. This distance of W feet is known as the hydrostatic head and must be overcome before the 30 fluids may be collected from vertical well bore 30.
Referring now to FIGURE 2B, a slant entry well 34 is shown with an articulated well bore 36 extending into coal seam 22. Slant entry well 34 is shown at an angle a away from the vertical. As illustrated, fluids collected from coal seam 22 must travel along articulated well bore 36 up to slant entry well 34, a distance of W' feet.
Thus, the hydrostatic head of a slant entry well system is reduced as compared to a substantially vertical system. Furthermore, by forming slant entry well 34 at angle a, the articulated well bore 36 drilled from tangent or kick off point 38 has a greater radius of curvature than articulated well bore 32 associated with vertical well bore 30. This allows for articulated well bore 36 to be longer than articulated well bore 32 (since the friction of a drill string against the radiused portion is reduced), thereby penetrating further into coal seam 22 and draining more of the subterranean zone.
FIGURE 3 illustrates an example method of forming a slant entry well 20. The steps of FIGURE 3 will be further illustrated in subsequent FIGURES 4-8. The method begins at step 100 wherein an entry well bore is formed. At step 105, a fresh water casing or other suitable casing is installed into the entry well bore formed at step 100. At step 110, the fresh water casing is cemented in place inside the entry well bore of step 100.
At step 115, a drill string is inserted through the entry well bore, and is used to drill approximately fifty feet past the casing. In some embodiments, a short, radiused bore is formed. In some embodiments, the radiused bore may be two hundred feet long and articulate thirty-five degrees over its length. It will be understood that other lengths and degrees may be employed based on the local geology and topography. At step 120, the drill is oriented to the desired angle of the slant well and, at step 125, a slant well bore is drilled down into and through the target subterranean zone. At step 130, one or more cavities are formed in the slant well.
At step 135 the slant well casing is installed.
Next, at step 140, a short radius curve is drilled into the target coal seam. Next, at step 145, a substantially horizontal well bore is drilled into and along the coal seam. It will be understood that the substantially horizontal well bore may depart from a horizontal orientation to account for changes in the orientation of the coal seam. Next, at step 150, a drainage pattern is drilled into the coal seam through the substantially horizontal well. The drainage pattern may comprise a pinnate pattern, a crow's foot pattern, or other suitable pattern. At decisional step 155, a determination is made whether additional subterranean zones are to be drained as, for example, when multiple subterranean zones are present at varying depths below the surface. If additional subterranean zones are to be drained, the process repeats steps 140 through 155 for each additional subterranean zone. If no further subterranean zones are to be drained, the process continues to step 160.
At decisional step 160, a determination is made whether additional slant wells are required. If additional slant wells are required, the process returns along the Yes branch to step 100 and repeats through step 155. A separate entry well bore may be formed for each individual slant well bore. Thus, for each slant well, the process begins at step 100, wherein a substantially vertical well bore is found. In some embodiments, however, multiple slant wells may be formed from one entry well bore.
If no additional slant wells are required, the process continues along the No branch to step 165.
5 At step 165, production equipment is installed into each slant well and at step 170 the process ends with the production of water and gas from the subterranean zone.
Although the steps have been described in a certain order, it will be understood that they may be performed l0 in any other appropriate order. Furthermore, one or more steps may be omitted, or additional steps performed, as appropriate.
For example, where multiple target zones are present (as determined at step 155), an enlarged diameter cavity may be found (step 130) above each target zone before any of the short radius curves are drilled (step 140).
Alternatively, all of the short radius curves may be found in each target zone (step 140) before any enlarged diameter cavities are found (step 130). Other suitable modifications will be apparent to one skilled in the art.
FIGURE 4 illustrates entry well bore 15 and casing 44 in its operative mode as a slant well 20 is about to be drilled. Corresponding with step 110 of FIGURE 3, a cement retainer 46 is poured or otherwise installed around the casing inside entry well bore 15. The cement casing may be any mixture or substance suitable to maintain casing 44 in the desired position with respect to entry well bore 15. A drill string 50 is positioned to begin forming a slant well. In order to keep drill string 50 relatively centered in casing 44, a stabilizer 52 may be employed. Stabilizer 52 may be a ring and fin type stabilizer or any other stabilizer suitable to keep drill string 50 relatively centered. To keep stabilizer 52 at a desired depth in well bore 15, stop ring 53 may be employed. Stop ring 53 may be constructed of rubber or metal or any other suitable down-hole environment material.
FIGURE 5 illustrates an example system of a slant well 20. Corresponding with step 115 of FIGURE 3, well bore 60 is drilled approximately fifty feet past the end of entry well bore 15 (although any other appropriate distance may be drilled). Well bore 60 is drilled away from casing 44 in order to minimize magnetic interference and improve the ability of the drilling crew to guide the drill bit in the desired direction. As described above in conjunction with FIGURE 3, well bore 60 may also comprise an articulated well bore with a radius of thirty-five degrees in two hundred feet.
Corresponding with step 120 of FIGURE 3, the drill bit is oriented in preparation for drilling slant entry well bore 64. Corresponding with step 125 of FIGURE 3, a slant entry well bore 64 is drilled from the end of the radius well bore 62 into and through. the subterranean zone 22. Alternatively, slant well 20 may be drilled directly from entry well bore 15, without including tangent well bore 60 or radiused well bore. A rat hole 66, which is an extension of slant well 64, is also formed. Rat hole 66 may also be an enlarged diameter cavity or other suitable structure. Corresponding with step 130 of FIGURE 3, a cavity 26 is formed in slant well 64 .
Cavity 26 acts as a velocity reduction chamber, separating entrained liquids from gasses destined for the surface. Without at least one cavity 26 located closer to the surface than the shallowest lateral well bore, entrained liquids form a mist that raises down-hole pressure. Friction is increased by the liquids entrained in escaping gasses, creating increased back pressure (down-hole pressure). Reducing the gas velocity separates out the liquid as the velocity drops below the speed at which the gas can entrain liquids. Cavity 26 lowers the velocity of the gas enough to separate out the entrained liquids, allowing the gas to proceed to the surface more efficiently.
In the illustrated embodiment, cavity 26 is shown immediately above the expected kick-off point for a subsequent short radiused well bore. It will be understood that cavity 26 may be otherwise suitably located. Moreover, it will be understood that cavity 26 may also be formed after the horizontal drainage pattern is formed.
FIGURE 6 is an illustration of the positioning of the casing in a slant well 64. For ease of illustration, only one slant well 64 is shown. Corresponding with step 135 of FIGURE 3, a whipstock casing 70 is installed into the slant entry well bore 64. In the illustrated embodiment, whipstock casing 70 includes a whipstock 72 which is used to mechanically direct a drill string into a desired orientation. It will be understood that other suitable techniques may be employed and the use of a whipstock 72 is not necessary when other suitable methods of orienting a drill bit through slant well 64 into the subterranean zone 22 are used. Whipstock casing 70 is oriented such that whipstock 72 is positioned so that a subsequent drill bit is aligned to drill into the subterranean zone 22 at a desired depth.
FIGURE 7 illustrates whipstock casing 70 and slant entry well bore 64 in further detail. As discussed in conjunction with FIGURE 6, whipstock casing 70 is positioned within slant entry well bore 64 such that a drill string 50 will be oriented to pass through slant entry well bore 64 at a desired tangent or kick off point 38. This corresponds with step 140 of FIGURE 3. Drill string 50 is used to drill through slant entry well bore 64 at tangent or kick off point 38 to form articulated well bore 36. In a particular embodiment, articulated well bore 36 has a radius of approximately seventy-one feet and a curvature of approximately eighty degrees per one hundred feet. In the same embodiment, slant entry well 64 is angled away from the vertical at approximately ten degrees. In this embodiment, the hydrostatic head generated in conjunction with production is roughly thirty feet. However, it should be understood that any other appropriate radius, curvature, and slant angle may be used.
FIGURE 8 illustrates a slant entry well 64 and articulated well bore 36 after drill string 50 has been used to form articulated well bore 36. In a particular embodiment, a horizontal well and drainage pattern may then be formed in subterranean zone 22, as represented by step 145 and step 150 of FIGURE 3.
Referring to FIGURE 8, whipstock casing 70 is set on the bottom of rat hole 66 to prepare for production of oil and gas. A sealer ring 74 may be used around the whipstock casing 70 to prevent gas produced from articulated well bore 36 from escaping outside whipstock casing 70. Gas ports 76 allow escaping gas to enter into and up through whipstock casing 70 for collection at the surface. As described above, liquids entrained in the escaping gas may be separated from the gas in enlarged diameter cavities 26 situated above the articulated well bore 36. As the liquids separate from the gas, the liquids travel down slant well 64 and are collected in rat hole 66. Rat hole 66 may also comprise an enlarged diameter cavity (not shown) to Collect liquids arriving from above.
A pump string 78 and submersible pump 80 is used to remove water and other liquids that are collected from the subterranean zone through articulated well bore 36.
As shown in FIGURE 9, the liquids, under the power of gravity and the pressure in subterranean zone 22, pass through articulated well bore 36 and down slant entry well bore 64 into rat hole 66. From there the liquids travel into the opening in the whipstock 72 of whipstock casing 70 where they come in contact with the installed pump string 78 and submersible pump 80. Submersible pump 80 may be a variety of submersible pumps suitable for use in a down-hole environment to remove liquids and pump them to the surface through pump string 78. Installation of pump string 78 and submersible pump 80 corresponds with step 165 of FIGURE 3. Production of liquid and gas corresponds with step 170 of FIGURE 3.
FIGURE 9 illustrates an example drainage pattern 90 that may be drilled from articulated well bores 36. At the center of drainage pattern 90 is a plurality of entry well bores 15 on a drilling pad 92 at the surface. In one embodiment, entry well bores 15 are spaced approximately twenty feet apart. It will be understood that other suitable spacings may also be employed.
Connecting to each entry well bore 15 is a slant well 20. At the terminus of slant well 20, as described above, are substantially horizontal well bores 94 roughly forming a "crow's foot" pattern off of each of the slant 5 wells 20. It will be understood that any other suitable drainage patterns, for example, a pinnate pattern, may be used. In an example embodiment, the horizontal reach of each substantially horizontal well bore 94 is approximately three hundred feet. Additionally, the 10 lateral spacing between the parallel substantially horizontal well bores 94 is approximately eight hundred feet. ,In this particular embodiment, a drainage area of approximately six hundred and forty acres would result.
Although the present invention has been described 15 with several embodiments, various changes and modifications may be suggested to one skilled in the art.
It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.
Claims (24)
1. A method for accessing a subterranean zone from the surface, comprising:
forming a first entry well bore from the surface;
forming one or more slanted well bores from the first entry well bore to the subterranean zone;
forming a second entry well bore from the surface, the second entry well bore located on the same drilling location as the first entry well bore at the surface;
forming one or more slanted well bores from the second entry well bore to the subterranean zone;
forming a third entry well bore from the surface, the third entry well bore located on the same drilling location as the first and second entry well bores at the surface;
forming one or more slanted well bores from the third entry well bore to the subterranean zone; and forming a substantially horizontal drainage pattern through at least one of the slanted well bores into the subterranean zone.
forming a first entry well bore from the surface;
forming one or more slanted well bores from the first entry well bore to the subterranean zone;
forming a second entry well bore from the surface, the second entry well bore located on the same drilling location as the first entry well bore at the surface;
forming one or more slanted well bores from the second entry well bore to the subterranean zone;
forming a third entry well bore from the surface, the third entry well bore located on the same drilling location as the first and second entry well bores at the surface;
forming one or more slanted well bores from the third entry well bore to the subterranean zone; and forming a substantially horizontal drainage pattern through at least one of the slanted well bores into the subterranean zone.
2. The method of Claim 1, wherein the horizontal drainage patterns comprise a horizontal well bore extending from the slanted well bore and a plurality of lateral well bores extending from the horizontal well bore.
3. The method of Claim 2, wherein the horizontal drainage patterns comprise a crow's foot configuration.
4. The method of Claim 2, wherein the lateral well bores are configured to drain an area of the subterranean zone of at least 640 acres.
5. The method of Claim 2, wherein the horizontal drainage patterns comprise a pinnate configuration.
6. The method of Claim 1, further comprising removing resources from the subterranean zone through the horizontal drainage patterns to the surface.
7. The method of Claim 1, further comprising forming an enlarged cavity in each of the slanted well bores proximate to and above the subterranean zone.
8. The method of Claim 1, further comprising forming an enlarged cavity in each of the slanted well bores above the horizontal drainage pattern.
9. The method of Claim 7, wherein the enlarged cavity is located proximate to the junction of the slanted well bore and the substantially horizontal drainage pattern.
10. The method of Claim 1, wherein the first, second, and third entry well bores are spaced approximately twenty feet apart.
11. The method of Claim 1, further comprising forming a second horizontal drainage pattern from each of the slanted well bores into a second subterranean zone.
12. A system for accessing a subterranean zone from the surface, comprising:
a first entry well bore from the surface;
a second entry well bore from the surface, the second entry well bore located on the same drilling location as the first entry well bore at the surface;
a third entry well bore from the surface, the third entry well bore located on the same drilling location as the first and second entry well bores at the surface;
one or more slanted well bores extending from each of the first, second and third entry well bores to the subterranean zone; and a substantially horizontal drainage pattern drilled through at least one of the slanted well bores into the subterranean zone.
a first entry well bore from the surface;
a second entry well bore from the surface, the second entry well bore located on the same drilling location as the first entry well bore at the surface;
a third entry well bore from the surface, the third entry well bore located on the same drilling location as the first and second entry well bores at the surface;
one or more slanted well bores extending from each of the first, second and third entry well bores to the subterranean zone; and a substantially horizontal drainage pattern drilled through at least one of the slanted well bores into the subterranean zone.
13. The system of Claim 12, wherein the horizontal drainage patterns comprise a horizontal well bore extending from the slanted well bore and a plurality of lateral well bores extending from the horizontal well bore.
14. The system of Claim 13, wherein the horizontal drainage patterns comprise a crow's foot configuration.
15. The system of Claim 13, wherein the lateral well bores are configured to drain an area of the subterranean zone of at least 640 acres.
16. The system of Claim 13, wherein the horizontal drainage patterns comprise a pinnate configuration.
17. The system of Claim 12, further comprising an enlarged cavity in each of the slanted well bores proximate to the subterranean zone.
18. The system of Claim 12, further comprising an enlarged cavity in each of the slanted well bores between the surface and the horizontal drainage pattern.
19. The system of Claim 17, wherein the enlarged cavity is located proximate to the junction of the slanted well bore and the substantially horizontal drainage pattern.
20. The system of Claim 12, wherein the first, second, and third entry well bores are spaced approximately twenty feet apart at the surface.
21. The system of Claim 12, further comprising a second substantially horizontal drainage pattern extending from each slanted well bore into a second subterranean zone.
22. A system for accessing a subterranean zone from the surface, comprising:
three or more entry well bores extending from the surface;
one or more slanted well bores extending from each entry well bore to the subterranean zone;
a substantially horizontal drainage pattern drilled through at least one of the slanted well bores into the subterranean zone; and an enlarged cavity in each of the one or more slanted well bores, located proximate to the junction of the slanted well bore and the substantially horizontal drainage pattern.
three or more entry well bores extending from the surface;
one or more slanted well bores extending from each entry well bore to the subterranean zone;
a substantially horizontal drainage pattern drilled through at least one of the slanted well bores into the subterranean zone; and an enlarged cavity in each of the one or more slanted well bores, located proximate to the junction of the slanted well bore and the substantially horizontal drainage pattern.
23. A system for accessing multiple subterranean zones from the surface, comprising:
three or more entry well bores extending from the surface;
one or more slanted well bores extending from each entry well bore to one or more subterranean zones;
one or more substantially horizontal drainage patterns drilled through at least one of the slanted well bores into each of the one or more subterranean zones;
and one or more enlarged cavities in each of the slanted well bores positioned proximate to the junction of the slanted well bores and the one or more of the substantially horizontal drainage patterns.
three or more entry well bores extending from the surface;
one or more slanted well bores extending from each entry well bore to one or more subterranean zones;
one or more substantially horizontal drainage patterns drilled through at least one of the slanted well bores into each of the one or more subterranean zones;
and one or more enlarged cavities in each of the slanted well bores positioned proximate to the junction of the slanted well bores and the one or more of the substantially horizontal drainage patterns.
24. The system of Claim 23, wherein the three or more entry well bores are located on the same drilling pad.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/227,057 | 2002-08-22 | ||
| US10/227,057 US20040035582A1 (en) | 2002-08-22 | 2002-08-22 | System and method for subterranean access |
| PCT/US2003/026124 WO2004018835A2 (en) | 2002-08-22 | 2003-08-21 | System and method for subterranean access |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2495985A1 CA2495985A1 (en) | 2004-03-04 |
| CA2495985C true CA2495985C (en) | 2008-05-20 |
Family
ID=31887386
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002495985A Expired - Fee Related CA2495985C (en) | 2002-08-22 | 2003-08-21 | System and method for subterranean access |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20040035582A1 (en) |
| EP (1) | EP1546505A2 (en) |
| CN (1) | CN100535383C (en) |
| CA (1) | CA2495985C (en) |
| PL (1) | PL201821B1 (en) |
| WO (1) | WO2004018835A2 (en) |
Families Citing this family (52)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6280000B1 (en) | 1998-11-20 | 2001-08-28 | Joseph A. Zupanick | Method for production of gas from a coal seam using intersecting well bores |
| US6662870B1 (en) * | 2001-01-30 | 2003-12-16 | Cdx Gas, L.L.C. | Method and system for accessing subterranean deposits from a limited surface area |
| US8297377B2 (en) | 1998-11-20 | 2012-10-30 | Vitruvian Exploration, Llc | Method and system for accessing subterranean deposits from the surface and tools therefor |
| US7048049B2 (en) * | 2001-10-30 | 2006-05-23 | Cdx Gas, Llc | Slant entry well system and method |
| US8376052B2 (en) | 1998-11-20 | 2013-02-19 | Vitruvian Exploration, Llc | Method and system for surface production of gas from a subterranean zone |
| US7025154B2 (en) * | 1998-11-20 | 2006-04-11 | Cdx Gas, Llc | Method and system for circulating fluid in a well system |
| EA003899B1 (en) | 2000-04-24 | 2003-10-30 | Шелл Интернэшнл Рисерч Маатсхаппий Б.В. | Method for treating a hydrocarbons-containing formation |
| US6923275B2 (en) * | 2001-01-29 | 2005-08-02 | Robert Gardes | Multi seam coal bed/methane dewatering and depressurizing production system |
| US7243738B2 (en) * | 2001-01-29 | 2007-07-17 | Robert Gardes | Multi seam coal bed/methane dewatering and depressurizing production system |
| US6951247B2 (en) | 2001-04-24 | 2005-10-04 | Shell Oil Company | In situ thermal processing of an oil shale formation using horizontal heat sources |
| NZ532091A (en) | 2001-10-24 | 2005-12-23 | Shell Int Research | In situ recovery from a hydrocarbon containing formation using barriers |
| US7360595B2 (en) * | 2002-05-08 | 2008-04-22 | Cdx Gas, Llc | Method and system for underground treatment of materials |
| US6991047B2 (en) * | 2002-07-12 | 2006-01-31 | Cdx Gas, Llc | Wellbore sealing system and method |
| US7025137B2 (en) * | 2002-09-12 | 2006-04-11 | Cdx Gas, Llc | Three-dimensional well system for accessing subterranean zones |
| EP1556580A1 (en) | 2002-10-24 | 2005-07-27 | Shell Internationale Researchmaatschappij B.V. | Temperature limited heaters for heating subsurface formations or wellbores |
| US7264048B2 (en) * | 2003-04-21 | 2007-09-04 | Cdx Gas, Llc | Slot cavity |
| NZ567052A (en) | 2003-04-24 | 2009-11-27 | Shell Int Research | Thermal process for subsurface formations |
| US20060201715A1 (en) * | 2003-11-26 | 2006-09-14 | Seams Douglas P | Drilling normally to sub-normally pressured formations |
| US20060201714A1 (en) * | 2003-11-26 | 2006-09-14 | Seams Douglas P | Well bore cleaning |
| US7419223B2 (en) * | 2003-11-26 | 2008-09-02 | Cdx Gas, Llc | System and method for enhancing permeability of a subterranean zone at a horizontal well bore |
| US7222670B2 (en) * | 2004-02-27 | 2007-05-29 | Cdx Gas, Llc | System and method for multiple wells from a common surface location |
| EP1738052B1 (en) | 2004-04-23 | 2008-04-16 | Shell International Research Maatschappij B.V. | Inhibiting reflux in a heated well of an in situ conversion system |
| US7278497B2 (en) * | 2004-07-09 | 2007-10-09 | Weatherford/Lamb | Method for extracting coal bed methane with source fluid injection |
| US7311150B2 (en) * | 2004-12-21 | 2007-12-25 | Cdx Gas, Llc | Method and system for cleaning a well bore |
| US7225872B2 (en) * | 2004-12-21 | 2007-06-05 | Cdx Gas, Llc | Perforating tubulars |
| US7353877B2 (en) * | 2004-12-21 | 2008-04-08 | Cdx Gas, Llc | Accessing subterranean resources by formation collapse |
| US7299864B2 (en) * | 2004-12-22 | 2007-11-27 | Cdx Gas, Llc | Adjustable window liner |
| US7831134B2 (en) | 2005-04-22 | 2010-11-09 | Shell Oil Company | Grouped exposed metal heaters |
| US7571771B2 (en) * | 2005-05-31 | 2009-08-11 | Cdx Gas, Llc | Cavity well system |
| WO2007050446A2 (en) | 2005-10-24 | 2007-05-03 | Shell Internationale Research Maatschappij B.V. | Methods of filtering a liquid stream produced from an in situ heat treatment process |
| US8381806B2 (en) | 2006-04-21 | 2013-02-26 | Shell Oil Company | Joint used for coupling long heaters |
| US7648348B2 (en) * | 2006-06-28 | 2010-01-19 | Scallen Richard E | Dewatering apparatus |
| CA2666959C (en) | 2006-10-20 | 2015-06-23 | Shell Internationale Research Maatschappij B.V. | Moving hydrocarbons through portions of tar sands formations with a fluid |
| US7950453B2 (en) | 2007-04-20 | 2011-05-31 | Shell Oil Company | Downhole burner systems and methods for heating subsurface formations |
| CN101835953B (en) * | 2007-08-23 | 2015-04-22 | 普拉德研究及开发股份有限公司 | Well construction using small laterals |
| CA2700998C (en) | 2007-10-19 | 2014-09-02 | Shell Internationale Research Maatschappij B.V. | Irregular spacing of heat sources for treating hydrocarbon containing formations |
| AU2009251533B2 (en) | 2008-04-18 | 2012-08-23 | Shell Internationale Research Maatschappij B.V. | Using mines and tunnels for treating subsurface hydrocarbon containing formations |
| AU2009303604B2 (en) | 2008-10-13 | 2013-09-26 | Shell Internationale Research Maatschappij B.V. | Circulated heated transfer fluid heating of subsurface hydrocarbon formations |
| US8851170B2 (en) | 2009-04-10 | 2014-10-07 | Shell Oil Company | Heater assisted fluid treatment of a subsurface formation |
| CA2713703C (en) * | 2009-09-24 | 2013-06-25 | Conocophillips Company | A fishbone well configuration for in situ combustion |
| US9127523B2 (en) | 2010-04-09 | 2015-09-08 | Shell Oil Company | Barrier methods for use in subsurface hydrocarbon formations |
| US8701769B2 (en) | 2010-04-09 | 2014-04-22 | Shell Oil Company | Methods for treating hydrocarbon formations based on geology |
| US8875788B2 (en) | 2010-04-09 | 2014-11-04 | Shell Oil Company | Low temperature inductive heating of subsurface formations |
| US8631866B2 (en) | 2010-04-09 | 2014-01-21 | Shell Oil Company | Leak detection in circulated fluid systems for heating subsurface formations |
| US9016370B2 (en) | 2011-04-08 | 2015-04-28 | Shell Oil Company | Partial solution mining of hydrocarbon containing layers prior to in situ heat treatment |
| MX2014008500A (en) * | 2012-02-14 | 2014-10-14 | Halliburton Energy Serv Inc | Shear wave source for vsp and surface seismic exploration. |
| US20140076530A1 (en) * | 2012-09-18 | 2014-03-20 | Alejandro Augusto Alvarez De Toledo | Facility with wells having multiple horizontal galleries for lowering water tables |
| US20140227035A1 (en) * | 2013-02-12 | 2014-08-14 | Chesapeake Operating, Inc. | Well pad drain and containment recovery system |
| CN103161440A (en) * | 2013-02-27 | 2013-06-19 | 中联煤层气国家工程研究中心有限责任公司 | Single-well coalbed methane horizontal well system and finishing method thereof |
| US9732594B2 (en) | 2013-05-20 | 2017-08-15 | Robert Gardes | Continuous circulating concentric casing managed equivalent circulating density (ECD) drilling for methane gas recovery from coal seams |
| EP3574183A4 (en) * | 2016-10-26 | 2020-03-18 | Davis, Jimmy L. | Method of drilling vertical and horizontal pathways to mine for solid natural resources |
| CN108590595B (en) * | 2018-04-10 | 2020-04-21 | 广东石油化工学院 | Method for exploiting non-diagenetic natural gas hydrate by utilizing F-shaped well group |
Family Cites Families (103)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US422611A (en) * | 1890-03-04 | Band twisting machine | ||
| US177961A (en) * | 1876-05-30 | Improvement in the treatment of plow mold-boards | ||
| US1089184A (en) * | 1913-09-18 | 1914-03-03 | Robert H Bolen | Mold for forming sunken concrete structures. |
| US1485615A (en) * | 1920-12-08 | 1924-03-04 | Arthur S Jones | Oil-well reamer |
| US2069481A (en) * | 1935-03-25 | 1937-02-02 | Richard A Rott | Refrigerated truck |
| US2150228A (en) * | 1936-08-31 | 1939-03-14 | Luther F Lamb | Packer |
| US2783018A (en) * | 1955-02-11 | 1957-02-26 | Vac U Lift Company | Valve means for suction lifting devices |
| US2934904A (en) * | 1955-09-01 | 1960-05-03 | Phillips Petroleum Co | Dual storage caverns |
| US2980142A (en) * | 1958-09-08 | 1961-04-18 | Turak Anthony | Plural dispensing valve |
| US3385382A (en) * | 1964-07-08 | 1968-05-28 | Otis Eng Co | Method and apparatus for transporting fluids |
| US3443648A (en) * | 1967-09-13 | 1969-05-13 | Fenix & Scisson Inc | Earth formation underreamer |
| US3809519A (en) * | 1967-12-15 | 1974-05-07 | Ici Ltd | Injection moulding machines |
| US3578077A (en) * | 1968-05-27 | 1971-05-11 | Mobil Oil Corp | Flow control system and method |
| US3503377A (en) * | 1968-07-30 | 1970-03-31 | Gen Motors Corp | Control valve |
| US3687204A (en) * | 1970-09-08 | 1972-08-29 | Shell Oil Co | Curved offshore well conductors |
| USRE32623E (en) * | 1970-09-08 | 1988-03-15 | Shell Oil Company | Curved offshore well conductors |
| US3800830A (en) * | 1973-01-11 | 1974-04-02 | B Etter | Metering valve |
| US3874413A (en) * | 1973-04-09 | 1975-04-01 | Vals Construction | Multiported valve |
| US4022279A (en) * | 1974-07-09 | 1977-05-10 | Driver W B | Formation conditioning process and system |
| US3934649A (en) * | 1974-07-25 | 1976-01-27 | The United States Of America As Represented By The United States Energy Research And Development Administration | Method for removal of methane from coalbeds |
| US3957082A (en) * | 1974-09-26 | 1976-05-18 | Arbrook, Inc. | Six-way stopcock |
| SE386500B (en) * | 1974-11-25 | 1976-08-09 | Sjumek Sjukvardsmek Hb | GAS MIXTURE VALVE |
| US4020901A (en) * | 1976-01-19 | 1977-05-03 | Chevron Research Company | Arrangement for recovering viscous petroleum from thick tar sand |
| US4073351A (en) * | 1976-06-10 | 1978-02-14 | Pei, Inc. | Burners for flame jet drill |
| US4089374A (en) * | 1976-12-16 | 1978-05-16 | In Situ Technology, Inc. | Producing methane from coal in situ |
| US4136996A (en) * | 1977-05-23 | 1979-01-30 | Texaco Development Corporation | Directional drilling marine structure |
| US4151880A (en) * | 1977-10-17 | 1979-05-01 | Peabody Vann | Vent assembly |
| US4156437A (en) * | 1978-02-21 | 1979-05-29 | The Perkin-Elmer Corporation | Computer controllable multi-port valve |
| US4182423A (en) * | 1978-03-02 | 1980-01-08 | Burton/Hawks Inc. | Whipstock and method for directional well drilling |
| US4257650A (en) * | 1978-09-07 | 1981-03-24 | Barber Heavy Oil Process, Inc. | Method for recovering subsurface earth substances |
| US4366988A (en) * | 1979-02-16 | 1983-01-04 | Bodine Albert G | Sonic apparatus and method for slurry well bore mining and production |
| US4312377A (en) * | 1979-08-29 | 1982-01-26 | Teledyne Adams, A Division Of Teledyne Isotopes, Inc. | Tubular valve device and method of assembly |
| US4317492A (en) * | 1980-02-26 | 1982-03-02 | The Curators Of The University Of Missouri | Method and apparatus for drilling horizontal holes in geological structures from a vertical bore |
| US4328577A (en) * | 1980-06-03 | 1982-05-04 | Rockwell International Corporation | Muldem automatically adjusting to system expansion and contraction |
| US4372398A (en) * | 1980-11-04 | 1983-02-08 | Cornell Research Foundation, Inc. | Method of determining the location of a deep-well casing by magnetic field sensing |
| US4442896A (en) * | 1982-07-21 | 1984-04-17 | Reale Lucio V | Treatment of underground beds |
| FR2545006B1 (en) * | 1983-04-27 | 1985-08-16 | Mancel Patrick | DEVICE FOR SPRAYING PRODUCTS, ESPECIALLY PAINTS |
| US4502733A (en) * | 1983-06-08 | 1985-03-05 | Tetra Systems, Inc. | Oil mining configuration |
| US4512422A (en) * | 1983-06-28 | 1985-04-23 | Rondel Knisley | Apparatus for drilling oil and gas wells and a torque arrestor associated therewith |
| US4494616A (en) * | 1983-07-18 | 1985-01-22 | Mckee George B | Apparatus and methods for the aeration of cesspools |
| CA1210992A (en) * | 1983-07-28 | 1986-09-09 | Quentin Siebold | Off-vertical pumping unit |
| FR2551491B1 (en) * | 1983-08-31 | 1986-02-28 | Elf Aquitaine | MULTIDRAIN OIL DRILLING AND PRODUCTION DEVICE |
| US4565152A (en) * | 1983-12-19 | 1986-01-21 | Bennett Charles O | Safety flag |
| US4519463A (en) * | 1984-03-19 | 1985-05-28 | Atlantic Richfield Company | Drainhole drilling |
| US4646836A (en) * | 1984-08-03 | 1987-03-03 | Hydril Company | Tertiary recovery method using inverted deviated holes |
| US4773488A (en) * | 1984-08-08 | 1988-09-27 | Atlantic Richfield Company | Development well drilling |
| US4651836A (en) * | 1986-04-01 | 1987-03-24 | Methane Drainage Ventures | Process for recovering methane gas from subterranean coalseams |
| US4662440A (en) * | 1986-06-20 | 1987-05-05 | Conoco Inc. | Methods for obtaining well-to-well flow communication |
| US4727937A (en) * | 1986-10-02 | 1988-03-01 | Texaco Inc. | Steamflood process employing horizontal and vertical wells |
| US4718485A (en) * | 1986-10-02 | 1988-01-12 | Texaco Inc. | Patterns having horizontal and vertical wells |
| US4889199A (en) * | 1987-05-27 | 1989-12-26 | Lee Paul B | Downhole valve for use when drilling an oil or gas well |
| CA2009782A1 (en) * | 1990-02-12 | 1991-08-12 | Anoosh I. Kiamanesh | In-situ tuned microwave oil extraction process |
| NL9000426A (en) * | 1990-02-22 | 1991-09-16 | Maria Johanna Francien Voskamp | METHOD AND SYSTEM FOR UNDERGROUND GASIFICATION OF STONE OR BROWN. |
| US5194859A (en) * | 1990-06-15 | 1993-03-16 | Amoco Corporation | Apparatus and method for positioning a tool in a deviated section of a borehole |
| US5197783A (en) * | 1991-04-29 | 1993-03-30 | Esso Resources Canada Ltd. | Extendable/erectable arm assembly and method of borehole mining |
| US5193620A (en) * | 1991-08-05 | 1993-03-16 | Tiw Corporation | Whipstock setting method and apparatus |
| US5197553A (en) * | 1991-08-14 | 1993-03-30 | Atlantic Richfield Company | Drilling with casing and retrievable drill bit |
| US5199496A (en) * | 1991-10-18 | 1993-04-06 | Texaco, Inc. | Subsea pumping device incorporating a wellhead aspirator |
| US5201817A (en) * | 1991-12-27 | 1993-04-13 | Hailey Charles D | Downhole cutting tool |
| US5289888A (en) * | 1992-05-26 | 1994-03-01 | Rrkt Company | Water well completion method |
| US5301760C1 (en) * | 1992-09-10 | 2002-06-11 | Natural Reserve Group Inc | Completing horizontal drain holes from a vertical well |
| US5485089A (en) * | 1992-11-06 | 1996-01-16 | Vector Magnetics, Inc. | Method and apparatus for measuring distance and direction by movable magnetic field source |
| US5402851A (en) * | 1993-05-03 | 1995-04-04 | Baiton; Nick | Horizontal drilling method for hydrocarbon recovery |
| US5394950A (en) * | 1993-05-21 | 1995-03-07 | Gardes; Robert A. | Method of drilling multiple radial wells using multiple string downhole orientation |
| US5727629A (en) * | 1996-01-24 | 1998-03-17 | Weatherford/Lamb, Inc. | Wellbore milling guide and method |
| US5385205A (en) * | 1993-10-04 | 1995-01-31 | Hailey; Charles D. | Dual mode rotary cutting tool |
| US5494121A (en) * | 1994-04-28 | 1996-02-27 | Nackerud; Alan L. | Cavern well completion method and apparatus |
| US5564503A (en) * | 1994-08-26 | 1996-10-15 | Halliburton Company | Methods and systems for subterranean multilateral well drilling and completion |
| US5501273A (en) * | 1994-10-04 | 1996-03-26 | Amoco Corporation | Method for determining the reservoir properties of a solid carbonaceous subterranean formation |
| US5540282A (en) * | 1994-10-21 | 1996-07-30 | Dallas; L. Murray | Apparatus and method for completing/recompleting production wells |
| US5501279A (en) * | 1995-01-12 | 1996-03-26 | Amoco Corporation | Apparatus and method for removing production-inhibiting liquid from a wellbore |
| US5732776A (en) * | 1995-02-09 | 1998-03-31 | Baker Hughes Incorporated | Downhole production well control system and method |
| US5868210A (en) * | 1995-03-27 | 1999-02-09 | Baker Hughes Incorporated | Multi-lateral wellbore systems and methods for forming same |
| US5706871A (en) * | 1995-08-15 | 1998-01-13 | Dresser Industries, Inc. | Fluid control apparatus and method |
| US5785133A (en) * | 1995-08-29 | 1998-07-28 | Tiw Corporation | Multiple lateral hydrocarbon recovery system and method |
| US5720356A (en) * | 1996-02-01 | 1998-02-24 | Gardes; Robert | Method and system for drilling underbalanced radial wells utilizing a dual string technique in a live well |
| US5944107A (en) * | 1996-03-11 | 1999-08-31 | Schlumberger Technology Corporation | Method and apparatus for establishing branch wells at a node of a parent well |
| US6056059A (en) * | 1996-03-11 | 2000-05-02 | Schlumberger Technology Corporation | Apparatus and method for establishing branch wells from a parent well |
| US5879057A (en) * | 1996-11-12 | 1999-03-09 | Amvest Corporation | Horizontal remote mining system, and method |
| US5863283A (en) * | 1997-02-10 | 1999-01-26 | Gardes; Robert | System and process for disposing of nuclear and other hazardous wastes in boreholes |
| US5884704A (en) * | 1997-02-13 | 1999-03-23 | Halliburton Energy Services, Inc. | Methods of completing a subterranean well and associated apparatus |
| US6019173A (en) * | 1997-04-04 | 2000-02-01 | Dresser Industries, Inc. | Multilateral whipstock and tools for installing and retrieving |
| US6030048A (en) * | 1997-05-07 | 2000-02-29 | Tarim Associates For Scientific Mineral And Oil Exploration Ag. | In-situ chemical reactor for recovery of metals or purification of salts |
| US20020043404A1 (en) * | 1997-06-06 | 2002-04-18 | Robert Trueman | Erectable arm assembly for use in boreholes |
| US5868202A (en) * | 1997-09-22 | 1999-02-09 | Tarim Associates For Scientific Mineral And Oil Exploration Ag | Hydrologic cells for recovery of hydrocarbons or thermal energy from coal, oil-shale, tar-sands and oil-bearing formations |
| US6050335A (en) * | 1997-10-31 | 2000-04-18 | Shell Oil Company | In-situ production of bitumen |
| US6012320A (en) * | 1998-01-14 | 2000-01-11 | Oxford Suspension, Inc. | Leaf spring straightening apparatus |
| US6024171A (en) * | 1998-03-12 | 2000-02-15 | Vastar Resources, Inc. | Method for stimulating a wellbore penetrating a solid carbonaceous subterranean formation |
| US6135208A (en) * | 1998-05-28 | 2000-10-24 | Halliburton Energy Services, Inc. | Expandable wellbore junction |
| US6662870B1 (en) * | 2001-01-30 | 2003-12-16 | Cdx Gas, L.L.C. | Method and system for accessing subterranean deposits from a limited surface area |
| US6598686B1 (en) * | 1998-11-20 | 2003-07-29 | Cdx Gas, Llc | Method and system for enhanced access to a subterranean zone |
| US6679322B1 (en) * | 1998-11-20 | 2004-01-20 | Cdx Gas, Llc | Method and system for accessing subterranean deposits from the surface |
| US6280000B1 (en) * | 1998-11-20 | 2001-08-28 | Joseph A. Zupanick | Method for production of gas from a coal seam using intersecting well bores |
| US7025154B2 (en) * | 1998-11-20 | 2006-04-11 | Cdx Gas, Llc | Method and system for circulating fluid in a well system |
| US6681855B2 (en) * | 2001-10-19 | 2004-01-27 | Cdx Gas, L.L.C. | Method and system for management of by-products from subterranean zones |
| US6425448B1 (en) * | 2001-01-30 | 2002-07-30 | Cdx Gas, L.L.P. | Method and system for accessing subterranean zones from a limited surface area |
| US6199633B1 (en) * | 1999-08-27 | 2001-03-13 | James R. Longbottom | Method and apparatus for intersecting downhole wellbore casings |
| AU2002224445A1 (en) * | 2000-10-26 | 2002-05-06 | Joe E. Guyer | Method of generating and recovering gas from subsurface formations of coal, carbonaceous shale and organic-rich shales |
| US6722452B1 (en) * | 2002-02-19 | 2004-04-20 | Cdx Gas, Llc | Pantograph underreamer |
| US6976547B2 (en) * | 2002-07-16 | 2005-12-20 | Cdx Gas, Llc | Actuator underreamer |
| US7025137B2 (en) * | 2002-09-12 | 2006-04-11 | Cdx Gas, Llc | Three-dimensional well system for accessing subterranean zones |
| US8333245B2 (en) * | 2002-09-17 | 2012-12-18 | Vitruvian Exploration, Llc | Accelerated production of gas from a subterranean zone |
| US6860147B2 (en) * | 2002-09-30 | 2005-03-01 | Alberta Research Council Inc. | Process for predicting porosity and permeability of a coal bed |
-
2002
- 2002-08-22 US US10/227,057 patent/US20040035582A1/en not_active Abandoned
-
2003
- 2003-08-21 EP EP03793194A patent/EP1546505A2/en not_active Withdrawn
- 2003-08-21 PL PL375351A patent/PL201821B1/en not_active IP Right Cessation
- 2003-08-21 CN CNB038229420A patent/CN100535383C/en not_active Expired - Fee Related
- 2003-08-21 CA CA002495985A patent/CA2495985C/en not_active Expired - Fee Related
- 2003-08-21 WO PCT/US2003/026124 patent/WO2004018835A2/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| PL375351A1 (en) | 2005-11-28 |
| WO2004018835A3 (en) | 2004-03-25 |
| WO2004018835A2 (en) | 2004-03-04 |
| CA2495985A1 (en) | 2004-03-04 |
| CN100535383C (en) | 2009-09-02 |
| EP1546505A2 (en) | 2005-06-29 |
| PL201821B1 (en) | 2009-05-29 |
| AU2003265549A1 (en) | 2004-03-11 |
| CN1685131A (en) | 2005-10-19 |
| US20040035582A1 (en) | 2004-02-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2495985C (en) | System and method for subterranean access | |
| US7048049B2 (en) | Slant entry well system and method | |
| US7090009B2 (en) | Three-dimensional well system for accessing subterranean zones | |
| CN101158267B (en) | Method and system for accessing subterranean deposits from the surface | |
| US6425448B1 (en) | Method and system for accessing subterranean zones from a limited surface area | |
| AU2002349947A1 (en) | An entry well with slanted well bores and method | |
| US6598686B1 (en) | Method and system for enhanced access to a subterranean zone | |
| AU2002251776A1 (en) | Method and system for accessing subterranean zones from a limited surface area | |
| AU2003265549B2 (en) | System and method for subterranean access | |
| US20050051326A1 (en) | Method for making wells for removing fluid from a desired subterranean | |
| AU2007229426B2 (en) | Slant entry well system and method | |
| AU2007203633A1 (en) | System and method for subterranean access |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |