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
  • E21B23/00—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
  • E21B23/14—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells for displacing a cable or a cable-operated tool, e.g. for logging or perforating operations in deviated wells
• • 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
  • E21B23/00—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
  • E21B23/001—Self-propelling systems or apparatus, e.g. for moving tools within the horizontal portion of a borehole
• • 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
  • E21B4/00—Drives for drilling, used in the borehole
  • E21B4/18—Anchoring or feeding in the borehole

Definitions

• the present invention relates to a device for transporting various types of tools into and within substantially circular and extended reach wellbores or pipelines.
• pulling tools of various configurations are used.
• Most such tools are electro- hydraulic devices comprising advancing mechanisms that are driven by hydraulic motors mounted directly to the drive wheels.
• the hydraulic power is transferred to the drive wheels by way of various types of gear systems.
• US 5,184,676 relates to a pulling tool comprising to parallel arms. Drive wheels are forced against the wellbore wall by means of a trapezoidal lever arm arrangement. This arrangement is considered to be relatively complex, and includes a number of failure-prone components.
• US 5,736,821 relates to a two- wheel robot that is capable of operating in a pipeline. The wheels are forced against the pipe wall by their own weight and, additionally, the wheels are provided with magnets to create friction against the pipe wall.
• WO 2005/116484 relates to a pulling tool comprising two drive shafts used for driving a chain.
• the drive shafts are eccentrically positioned relative to the tool centre line, but the use of two drive shafts is necessary, one at each side of the chain, in order for the design to work.
• a challenge associated with pulling tools of the above type is to avoid torsional moments that either cause the pulling tool to progress along a helical path, and/or to assume a crooked position relative to the direction of movement of the pulling tool. Such torsional moments may result in that connected lines/coiled tubing become undesirably twisted, that the pulling tool loses traction, or that the tool jams.
• US 5,184,676 tries to solve this problem, and achieves a lower torsional moment.
• the solution involves several components that are prone to failure and wear.
• the present invention provides a pulling tool of the above kind that avoids a number of the disadvantages from which the conventional solutions suffer.
• the present invention provides a pulling tool comprising advancement means yielding a high efficiency and a large pulling/pushing force.
• Fig. Ia shows an embodiment comprising two separate modules, wherein each separate module includes to lever arms, each arm having one drive wheel,
• Fig. Ib shows an alternative embodiment comprising to separate modules, wherein each separate module includes one lever arm, the lever arm being centrally supported and having two drive wheels, one at each end of the lever arm,
• Fig. 2a shows a design of a gear system and a drive shaft that may be used in the embodiment shown in fig. Ia,
• Fig. 2b shows a design of a support that may be used in connection with the embodiment shown in fig. Ib comprising one lever arm, the lever arm being supported in the center thereof and having two drive wheels, one at each end of the lever arm
• Fig. 2c shows a design of a support of a lever arm having two drive wheels, with the figure also showing a design of a drive line forward to the driving wheels, cf. fig. Ib,
• Fig. 3 shows a design of a gear transmission between the drive shaft and wheels, cf. fig. Ia,
• Fig. 4a shows a section and a cross-section of a lever arm support, cf. fig. Ic ⁇
• Fig. 4b shows a section of a lever arm support, cf . fig. 1 ⁇
• Fig. 5a shows an embodiment of a device for actuating a lever arm having one drive wheel, cf. fig. Ia, and
• Fig. 6 shows an example of how a drive wheel may be supported.
• Figs. Ia and Ib show two different pulling tools according to the present invention comprising two separate modules, each of which includes two drive wheels.
• Fig. Ia shows an embodiment wherein each drive wheel 5 is mounted on a separate lever arm 4, whereas fig. 2a shows an embodiment wherein each drive wheel 5 is mounted at each end of one lever arm 4.
• the pulling tool is assembled using a desired number of separate modules 1 needed to obtain a sufficient axial pulling/pushing force by means of suitable threaded connections or adaptor means/elements.
• Figs. Ia and Ib show exemplary embodiments comprising two separate modules 1, although it is understood that any suitable number of separate modules 1 may be used.
• Each separate module 1 has a given pulling/pushing force, so that a desired total pulling/pushing force can be achieved by assembling a sufficient number of separate modules 1.
• the advancement of the pulling tool is effected by causing a drive shaft 7 to rotate, whereupon the rotational force from drive shaft 7 is transferred to drive wheels 5 via a number of cog wheels 12, 11 and cog wheel gears 21, 13, 14, 15, and 16 while at the same time drive wheels 5 are forced against the wellbore/pipe wall 6 by lever arms 4, cf. fig. 2a.
• all drive wheels are mechanically interlocked through a common drive line, which ensures that all wheels are engaged at the same time, which in turn prevents the uncontrolled wheel rotation should any wheel lose its grip on the wellbore/pipe wall.
• each separate module 1 includes two drive wheels, and one or two respective lever arms 4, depending on whether or not these are end supported with one drive wheel 5 at the one end, or centrally supported with one drive wheel 5 at each end.
• the drive wheels 5 of each separate module 1 are separated by 180° relative to each other.
• a connector adapter 3 is provided for connecting tools thereto.
• a control and drive section 2 is disposed at the end of the pulling tool, which communicates with the surface through a cable or coiled tubing 29.
• the rotational moment to driving wheels 5 is applied through cog wheel 9, which is centrically mounted on the longitudinal axis of the pulling tool. That is, the rotational moment is transferred from cog wheel 9, through cog wheel 8 and shaft 7, to an angular gear comprising cog wheels 11 and 12, and then through cog wheel gears 21, 13, 14, 15, and 16, which transfer the rotational moment to drive wheels 5.
• Figs. 2a and 3 detail this arrangement in the case of two lever arms 4 each having its own single drive wheel 5.
• An overload connection 17 is provided in conjunction with angular gear 12 and shaft 7, with pretension being adjusted by a spring 18, cf. fig. 2a.
• Cog wheel gears 8 and 9 are provided at each end of the through drive shaft 7, so that the transfer of moment from one individual module to the next is accomplished centrically through a cog wheel gear 9, cf. figs. 2a and 2b.
• Angular gear 11 (cf. fig. 4a) may be supported by a ball-bearing 23, with lever arm 4 being supported by circular sliding surfaces 26.
• a similar principle may be used for centrally supported lever arms 4 having one drive wheel at each end thereof (ref. fig. 4b), in which case angular gear 12 may be supported by a ball-bearing 23 and lever arms 4 is supported by circular sliding surfaces 26.
• lever arm 4 may be actuated by means of a hydraulic fluid pressure acting on pistons 25 engaged with a cogging element 32 connected to lever arm 4, cf. fig. 5a.
• a similar principle may be used for a center-supported lever arm 4 having two wheels, in which case lever arm 4 may be actuated by means of a hydraulic fluid pressure acting on pistons 28 in meshed engagement 32 with cog wheel shaft 32, cf. fig. 2b.
• Drive wheels 5 may be supported by a ball-bearing 36 of lever arm 4, cf. fig. 6. A similar principle may be used for center-supported lever arms 4 having one drive wheel 5 at each end.
• the pulling tool may include an overload connection that switches off the power to a drive wheel without significantly affecting the power to the remaining drive wheels.
• the lever arm still will force the wheel against the wellbore or pipe wall and make sure that the pulling tool remains centered in the wellbore/pipeline.
• such an overload connection may include a conical member 24 with an associated spring 18 (cf. fig. 4a).
• the pulling tool may be assembled from a number of separate modules 1, it being understood that each separate module 1 may include one or more drive wheels. Hence, the necessary pulling/pushing force may be provided by putting together a sufficient number of individual modules 1. If more than one separate module 1 is used, the drive wheels 5 of each separate module 1 may be positioned so as to form an angle of 90°, for example, to the drive wheels 5 of the previous and/or following separate module 1. Such a configuration may help improving the ability of the pulling tool to self-center within the substantially circular and extended reach wellbore or pipeline, as well as significantly improve the traction. It is understood that other angles may also be used, e.g. 45°, 60°, 120°, etc.
• Each separate module 1 is configured so that adaptor elements for transferring rotational forces and carrying lines and liquid across angles of 45°, 60°, 90°, 120°, etc., for example, may be provided between modules 1, with the separate modules being more or less identical and the adaptor elements determining the radial angles of the drive wheels of each following separate module.
• Power may be supplied through electric cables from the surface and through an electro motor for the gear transmission, or alternatively by means of a liquid motor/turbine driven by drilling fluid in connection with coiled tubing operations, for example.
• the size may be adapted and configured according to the particular needs.
• the functioning of the lever arms as such gives the pulling tool a relatively wide area of application with respect to the inner dimension of the wellbore or pipeline.
• the function of the lever arm will help allowing for relatively sharp bends to be traversed by means of a device according to the present invention, without the device getting stuck.

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• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
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• 2008
  • 2008-01-22 EP EP08712646.2A patent/EP2106493A4/de not_active Withdrawn
  • 2008-01-22 WO PCT/NO2008/000018 patent/WO2008091157A1/en active Application Filing

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