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
  • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
  • E21B19/02—Rod or cable suspensions
• • 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
  • E21B15/00—Supports for the drilling machine, e.g. derricks or masts
• • 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
  • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
  • E21B19/08—Apparatus for feeding the rods or cables; Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods
  • E21B19/086—Apparatus for feeding the rods or cables; Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods with a fluid-actuated cylinder

Definitions

• the present invention relates to an apparatus for a derrick, comprising two or more hydraulic piston/cylinder arrangements for raising and lowering a yoke which travels on guide rails in the derrick itself, where two or more wire lines are strung over sheaves rotatably attached to the yoke, said wire lines being at one end attached to the top drive and at the other end to an attachment point adjacent to a drill floor, said two or more wire lines being run in two sets of lines, the attachment points of which are spaced apart.
• a derrick structure developed by the present inventor in 1987, that has shown great promise is the RamRigTM concept.
• Two or more hydraulic piston/cylinder arrangements are used in the derrick for raising and lowering the drill string.
• the cylinders operate between the drill floor and a yoke which travels on guide rails in the derrick itself.
• the advantages of this concept are numerous, some of the most important being that it is possible to place the drill floor at a higher level than the platform floor, that a derrick having significantly lower air resistance can be constructed, and that the most expensive components of the derrick attain higher safety and a longer lifetime.
• the object of the present invention is to solve important, practical problems in the realization of the RamRigTM concept. This object is achieved by means of the features apparent from the characterizing clause of the subsequently disclosed claim 1.
• Figure 1 shows a RamRigTM derrick in every essential detail
• FIG. 1 shows the derrick schematically, viewed from the side
• Figure 3 shows the derrick schematically, viewed from the front, with the top drive in its lowest position
• Figure 4 shows the derrick schematically, viewed from the front, with the top drive in its highest position
• Figures 5 - 13 show the drive means of the piston/cylinder 0 arrangements in various modes of operation.
• Figure 1 shows a derrick 1 positioned on a drill floor 2.
• the drill floor is positioned at a higher level than the platform floor 3, so that the pipe handling equipment 4 can 5 be placed, in the main, between the platform floor 3 and the drill floor 2.
• the derrick 1 is substantially gantry-shaped, with gantry legs 5, 6.
• Guide rails 7 for a yoke 8 and a top- drive 9 run along each gantry leg 5, 6.
• Hydraulic piston/cyl ⁇ inder arrangements 10, 11 are positioned so that they extend ° along each gantry leg 5, 6 and operate between the drill floor 2 and the yoke 8, for moving the yoke 8 vertically along the guide rails 7.
• the yoke 8 is provided with a plurality of sheaves 12, pre-
• the wire lines 13 run from the drill floor 2 along each gantry leg 5, 6, over the sheaves 12 and down to the top drive 9. By retracting and extending the piston/cylinder arrangement 10, 11, it is thus possible to raise and lower the top drive 9.
• the yoke 8 When the pistons in the piston/cylinder arrangement are extended, the yoke 8 is lifted along the guide rails 7 up to the top of the derrick 1. The top drive is then lifted, as a result of the exchange created by the wire lines 13 being run " 5 over the sheaves 12, from Its position adjacent to the drill floor 2 to a position directly below the yoke 8. The height to which the top drive 9 is lifted is thus the double of that to which the yoke 8 is lifted.
• wire lines 13 may, for example, be as much as eight wire lines 13 arranged in the lift means described above, where two and two are strung in their own separate tracks over the same sheave 12. Four sheaves are arranged in pairs at each end of the yoke 8. The wire lines 13 are thus arranged in two sets 13a
• attachment points 14a and 14b are horizontally spaced apart by a distance approximately like the length of the yoke 8.
• each piston/cylinder arrangement 10, 11 consists of a cylinder and a piston 21 having a piston rod 22.
• the cylinder 20 is at one end attached to the drill floor 2, whereas the piston rod 22 is attached to the yoke 8.
• the piston 21 divides the cylinder into two chambers, a lower chamber 23 and an upper chamber 24.
• the lower chamber 23 is circular/cylindrical and only delimited by the walls of the cylinder 20 and the lower end surface 25 of the piston 21.
• the upper chamber 24 is also delimited by the walls of the cylinder 20, but is in addition delimited by the piston rod
• the drive system which is here generally designated by reference numeral 30, consists of a reservoir 31, a feed pump 32 driven by a motor 33, one or more main pumps 34 driven by one or more motors 35, a control valve 36, an accumulator/- valve plate 37, a cylinder valve 38 for each cylinder 20, one or more accumulators 39 and one or more pressure tanks 40.
• a line 43 leads from the reservoir 31, via the feed pump 38 to a third port c in the control valve 36.
• a line 44 leads to the accumulator/valve plate 37.
• a line 45 leads via a ramification 46, where the line 45 branches so as to create one line for each cylinder 20 leading into a port f in each cylinder valve 38.
• the line 44 which leads into a port g in the accumula ⁇ tor/valve plate 37, splits here into branches which lead from a number of ports h to the control valve 38 of each cylinder 20 into a port 1 for each control valve 36.
• the accumulators 39 are connected to the accumulator valve plate 37 via ports j. It must be understood that both ports h and ports j respectively may represent a plurality of ports or optionally one port branching outside the accumulator/valve plate 37.
• the accumulators 39 are connected to the pressure tanks 40 via a line 47.
• a line 48 connected with the upper chamber 24 of the cylinder 20, extends from a port k in each cylinder valve 38. From a port 1 in each cylinder valve a line 49 leads to the chamber 23 of the cylinder 20. A line 50 connects ports ra in each cylinder valve 38.
• the piston/cylinder arrangements are extended for maximum thrust power, but at low velocity.
• the displacement volume of the main pump 34 is adjusted so that hydraulic fluid flows from the reservoir 31, via the feed pump 32 and the line 43, in through the port c in the control valve 36, out through the port b, through the line 42 via the main pump 34 and the line 41 to port a of the control valve 36, out through the port e, via the line 44 to port g of the accumulator valve plate and from this via the ports h to the ports i in the cylinder valves 38 and further out through the ports 1 and the lines 49 to the chamber 23 of the cylinder 20.
• Hydraulic fluid displaced from the chamber 24 of the cylinder 20, flows via the lines 48, via the cylinder valves 38 and the line 45 back to the control valve 36 and main pump 34.
• the ports j In the accumulator valve plate 37 are closed.
• the connection 50 between the ports m of the cylinder valves 38 is open, however, in order to ensure that there is equal pressure on the underside 25 of the pistons 21. In this mode the piston/cylinder arrange ⁇ ments 10, 11 would be extended at a comparatively low velocity, but with a relatively high thrust power.
• FIG 7 another mode is shown which, with respect to hydraulic fluid circulation, Is quite in accordance with the mode shown in figure 6.
• the ports j in the accumulator valve plate 37 have been opened up so that the accumulators 39, which are influenced by pressure from pressure tanks 4 via the line 47, increase the pressure in the hydraulic fluid which flows through the line 44 to the lower chamber 23 of the cylinders 20.
• the velocity of the pistons 21 is then somewhat increased at the same time as the thrust power is maintained at a high level.
• FIG 8 a mode is shown where the travelling speed of the pistons 21 has been further increased. At the same time the thrust force is reduced.
• This mode is thus well suited for raising the unloaded top drive 9.
• the connection is opened between the ports 1, k, 1 and m in the control valves 38, so that the lower chamber 23 and the upper chamber 24 of the cylinders 20 are short circuited.
• the hydraulic pressure acts on a differential area which is equal to the difference between the area of the underside 25 of the piston 21 and the top side 26 of the piston 21, i.e. , the cross-sectional area of the piston rod 22.
• the piston 21 obtains a greater travelling speed at the same hydraulic pressure.
• 2o cylinder valves 38 is open so that the hydraulic fluid in chamber 23 of the cylinder 20 flows out in the line 44. A part of the hydraulic fluid will flow back to the reservoir 31 for the very reason that the chamber 24 of the cylinder 20 has a smaller cross sectional area than the chamber 23.
• FIG 11 a lowering mode is shown where the lowering is carried out at up to maximum load and up to maximum velocity.
• the ports f, i, k and 1 in the cylinder valves 38 are connected with each other.
• hydraulic fluid can freely
• Figure 12 shows a mode of operation where constant load is maintained during the movement of the piston/cylinder arrangements 10, 11.
• This mode is used, for example, for the drilling itself.
• the fluid flow goes back and forth in the system, and the displacement volume of the main pump 34 is adjusted in both directions in accordance with signals given from a load distributor (not shown).
• the connection between the ports f and k in the cylinder valve 38 is open, as is the connection between the ports i and 1.
• the hydraulic fluid thus flows between the main pump 34 and the cylinder valve 38 via the line 44 and the line 45, respec ⁇ tively.
• the directions of the flow of fluid in these two lines will at all times be opposite to each other.
• a certain exchange of hydraulic fluid with the reservoir 31 will also occur, since the cross-sectional areas of the lower chamber 23 of the cylinder 20 and of the upper chamber 24 are different.
• Figure 13 shows a similar mode of operation, where the purpose is to maintain a constant load while the pistons 21 are moved. In this mode, however, a greater velocity is achieved with respect to the travel of the piston.
• the port f in the valve 38 is now closed, so that there no longer will be any fluid flow in the line 45.
• the ports i, k and 1 in the cylinder valve 38 are connected with each other, however.
• the area of piston 21 activity will be the differential area between the area of the lower surface 25 of the piston and the area of the upper annular surface 26 of the piston. This corresponds to the cross-sectional area of the piston rod 22. A faster move of the piston 21 will then be obtained even if the pressure in the system is unchanged.

Landscapes

• Engineering & Computer Science (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Physics & Mathematics (AREA)
• Geochemistry & Mineralogy (AREA)
• Fluid-Pressure Circuits (AREA)
• Earth Drilling (AREA)
• Actuator (AREA)
• Forklifts And Lifting Vehicles (AREA)
• Load-Engaging Elements For Cranes (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19898876

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (3)

Citations (1)

• 1995
  • 1995-12-22 NO NO955271A patent/NO302047B1/no not_active IP Right Cessation
• 1996
  • 1996-12-18 EP EP96943394A patent/EP0868593B1/en not_active Expired - Lifetime
  • 1996-12-18 DE DE69631788T patent/DE69631788D1/de not_active Expired - Lifetime
  • 1996-12-18 KR KR1019980704780A patent/KR19990076668A/ko not_active Application Discontinuation
  • 1996-12-18 WO PCT/NO1996/000294 patent/WO1997023706A1/en active IP Right Grant
  • 1996-12-18 CA CA002240582A patent/CA2240582C/en not_active Expired - Fee Related
  • 1996-12-18 JP JP9523532A patent/JP2000502765A/ja active Pending
  • 1996-12-18 AT AT96943394T patent/ATE261054T1/de not_active IP Right Cessation
  • 1996-12-18 AU AU12133/97A patent/AU1213397A/en not_active Abandoned

Patent Citations (1)

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