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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
  • E21B17/07—Telescoping joints for varying drill string lengths; Shock absorbers
• • 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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/01—Risers
• • 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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/021—Devices for subsurface connecting or disconnecting by rotation
• • 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
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
  • E21B17/06—Releasing-joints, e.g. safety joints
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/32—Details
  • F16F9/34—Special valve constructions; Shape or construction of throttling passages

Definitions

• the present invention relates to a dampening assembly having a dampening function.
• the dampening function is achieved by controlling the outflow of water displaced from a confined space during landing of one tubular element into another tubular element.
• the invention also relates to a dampening assembly which is part of a heave eliminator assembly, which is provided with a damping function.
• riser assembly In the field of offshore oil and gas production and exploration, it is common to have a riser assembly extended between the seabed and a surface installation.
• the riser assembly constitutes a conduit between the surface installation and a seabed installation, typically an EDP/LRP (emergency disconnection package / lower riser package) on top of a Xmas tree, which in turn is on top of a subsea well.
• EDP/LRP electronic low-reconnection package
• Xmas tree Xmas tree
• rigid risers In order to prevent buckling damages to the riser assembly, rigid risers are kept under tension. That is, they are pulled upwards by the surface installation to maintain a fairly straight shape.
• the surface installation is a floating installation, such as a vessel or a floating platform
• the installation may move with respect to the riser assembly which is fixed to the seabed via the subsea well. That is, while the riser assembly remains in a constant vertical position with respect to the seabed, the floating installation will move up and down due to weather conditions.
• Such mutual movement between the upper portion of the riser assembly and the installation makes work on the riser and other associated riser string equipment, such as surface flow tree or wireline adaptor, hazardous.
• heave eliminator to the upper part of the riser assembly. The heave eliminator makes it possible to fix an upper portion of the riser assembly to the installation, thereby eliminating this mutual movement.
• This upper portion of the riser assembly will then, however, move with respect to a lower portion of the riser assembly.
• This movement is known to be accounted for with a telescopic joint or heave elimination joint (HE joint), wherein a part of the upper portion extends into a part of the lower portion so that the upper and lower portions may move telescopically within one another.
• HE joint heave elimination joint
• any high pressure such as well pressure
• the upper portion Before any high pressure, such as well pressure, may be let into the upper portion of the rise assembly, the upper portion must be securely connected to the lower portion. Such connection often takes place during heaving of the floating installation. Significant impacts may thus occur between the upper portion of the riser assembly and the lower portion. Such impacts may cause wearing and damage to the equipment. It would thus be favorable to reduce such impacts during connection and disconnection of the upper and lower portion of the riser assembly.
• dampening assembly comprising a first tubular element which is adapted to be coaxially inserted into a second tubular element along an insertion path that ends at an end position. At the end position an abutting face of the first tubular element abuts a landing face of the second tubular element.
• a displacement aperture is adapted to guide liquid out from a liquid compartment during insertion of the first tubular element.
• the liquid compartment is arranged between the first and second tubular elements. According to the invention, the area of the
• the displacement aperture exhibits a reduced size, the closer the first tubular element is to said end position.
• the displacement aperture is an opening through which liquid, typically water, may flow out from the liquid compartment when the first tubular element lands in the second tubular element.
• the area of the displacement aperture affects the dampening effect of the mutual movement between the two tubular elements. Since this area becomes gradually reduced during insertion along the insertion path towards the end position, the dampening effect increases.
• the first or second tubular element comprises a plurality of boundary slots that together with a facing internal face of the second tubular element or a facing outer face of the first tubular element, respectively, define a plurality of displacement apertures.
• the tangential extension of the boundary slots changes along the axial direction. This change provides the reduction of the displacement aperture during insertion towards the end position.
• a split ring or a continuous ring can advantageously be arranged on the first or second tubular element to constitute an inner or outer aperture boundary of said displacement apertures.
• the use of a ring to define the area of the displacement aperture makes it possible to adapt the displacement aperture according to desire in a readily fashion, as the ring can be replaced by a ring having another design or dimensions.
• the first or second tubular element is provided with a split ring that has a plurality of cutouts that face a facing tapered internal face of the second tubular element or a facing tapered outer face of the first tubular element, respectively.
• a split ring is adapted to be forced radially inwards or outwards, respectively, by the facing tapered face.
• Displacement apertures are arranged in the cutouts and a portion of the first or second tubular element, respectively, enters gradually into the area of the cutouts during movement of the first tubular element towards the end position, thereby reducing the area of the displacement apertures.
• the inner or outer tubular element can comprise a circular tapered boundary face which together with an end edge of an opposite face defines an annular displacement aperture.
• a tubular latch assembly adapted to connect a lower portion of an upper riser portion to an upper portion of a lower riser portion.
• the upper and lower riser portions are part of a riser assembly that extends from a floating structure to a seabed through a body of water.
• the lower riser portion is suspended from the floating structure with a tensioning system when in a position where the tubular latch assembly is in a disconnected mode.
• the tubular latch assembly is provided with a dampening assembly adapted to dampen movement of the upper riser portion towards the lower riser portion by means of water displacement through a displacement aperture during landing of the upper riser portion on the lower riser portion.
• the latch assembly according to the second aspect of the invention is thus provided with means for reducing harmful collisions between the upper and lower riser portions when these are joined together.
• the dampening assembly can advantageously be adapted to gradually increase the dampening effect as the upper riser portion moves along an insertion path towards an end position which is a landed position, as the displacement aperture reduces towards the end position.
• Fig. 1 is a principle side view of a floating structure supporting a riser assembly which extends vertically down to the seabed;
• Fig. 2 is a side cross section view of a tubular latch assembly for connecting an upper riser portion to a lower riser portion;
• Fig. 3 is a side view of the latch assembly shown in Fig. 2;
• Fig. 4 is a cross section view of the latch assembly shown in Fig. 2, wherein a first tubular element is landed in a second tubular element;
• Fig. 5 is a cross section view corresponding to Fig. 4, showing the first tubular element latched to the second tubular element;
• Fig. 6 is a cross section perspective view of a dampening assembly according to an embodiment of the invention.
• Fig. 7 is a cross section perspective view of the embodiment shown in Fig. 6, in an intermediate position in which the first tubular element is partially inserted into the second tubular element;
• Fig. 8 is a cross section perspective view corresponding to Fig. 6, showing the dampening assembly in a landed end position;
• Fig. 9 is a cross section perspective view of a segment of the dampening
• Fig. 10 is a view corresponding to Fig. 9 showing the assembly in an intermediate position
• Fig. 1 1 is a view corresponding to Fig. 9 showing the assembly in a landed
• Fig. 12 is a schematic top view illustrating a displacement area, through which displaced liquid flows during insertion of the first tubular element into the second tubular element;
• Fig. 13 is a view corresponding to Fig. 12, showing the assembly in an intermediate position
• Fig. 14 is a view corresponding to Fig. 12, showing the assembly in a landed position
• Fig. 15 is a schematic side view showing a detail of the assembly in the landed position
• Fig. 16 is a perspective view of another embodiment of a dampening assembly according to the invention.
• Fig. 17 is a cross section perspective view of yet another embodiment of a
• Fig. 18 to Fig. 21 are perspective cross section views of the embodiment shown in Fig. 17 at various positions;
• Fig. 22 to Fig. 24 are schematic top views of a detail of the dampening assembly shown in Fig. 17 at various positions;
• Fig. 25 is a perspective cross section view of a further embodiment of a
• Fig. 26 is a perspective view of yet another embodiment of a dampening
• Fig. 27 and Fig. 28 are cross section views of the dampening assembly of Fig.
• Fig. 29 is an enlarged cross section view of the embodiment shown in Fig. 26.
• Fig. 1 illustrates a portion of a floating structure 1 floating on a body of water having a water surface 3.
• a riser assembly 5 extends from the floating structure 1 down to the top of a subsea well 7 extending into the seabed (not shown).
• the riser assembly 5 comprises an upper riser portion 9 and a lower riser portion 1 1.
• the upper riser portion 9 is connectable to the upper part of the lower riser portion 1 1 by means of a tubular connector assembly which is provided with a dampening assembly 100 according to the invention.
• the lower riser portion 1 1 is maintained in its upright position through a tension ring 13 arranged at an upper section.
• the tension ring 13 is connected to the floating structure 1 through a heave compensated tensioning system 15.
• the tensioning system 15 will maintain a constant tension in the lower riser portion 1 1 during heave motions of the floating structure 1 . This function is well known to the person skilled in the art.
• Fig. 2 shows the dampening assembly 100 in more detail with a cross section view.
• the dampening assembly 100 is part of a tubular latch assembly 600 adapted to latch a first tubular element 21 to a second tubular element 23.
• the first tubular element 21 is adapted to be coaxially inserted into and locked to the second tubular element 23.
• Fig. 3 shows the first and second tubular elements 21 , 23 in a side view in a situation corresponding to the one shown in Fig. 2.
• the first tubular element 21 is the lower end portion of the upper riser portion 9 shown in Fig. 1
• the second tubular element 23 is the upper end portion of the lower riser portion 1 1 .
• Fig. 4 shows another cross section view of the dampening assembly 100.
• the first tubular element 21 has landed coaxially inside the second tubular element 23.
• a downwardly facing abutting face 25 of the first tubular element 21 has landed on an upwardly facing landing face 27 within the bore of the second tubular element 23.
• the second tubular element 23 is provided with the latch assembly 600.
• the latch assembly 600 comprises a plurality of radially moving locking dogs 29. The locking dogs 29 are moved radially into a locking position, as shown in Fig. 5, by means of an axially movable locking ring 31 .
• the locking ring 31 is connected to a plurality of hydraulic piston rods 32 which are moved by hydraulic actuation members 33. As shown in Fig. 5, the locking ring 31 actuates the locking dogs 29 into a locking position by axial movement, as inclined faces of the locking dogs 29 slides against an inclined actuation face of the locking ring 31 . If the insertion of the first tubular element 21 into the second tubular element 23 is done while surrounded by seawater, such as in the embodiment shown in Fig. 1 , some seawater must be displaced out from the second tubular element 23. This displacement results in a dampening effect when the first tubular element 21 is landed. Such dampening reduces the impact forces and thus also the wearing or potential damage of the two tubular elements 21 , 23 and associated seals and seal surfaces.
• Fig. 6 to Fig. 8 show cross section perspective views of a lower end portion of an upper tubular element 21 being inserted into the upper portion of a second tubular element 23.
• a liquid compartment 28 is provided between the first and second tubular elements 21 , 23.
• the liquid compartment 28 is sealed off in one axial direction by means of a seal 26 on the first tubular element 21 which seals against an inner bore of the second tubular element 23.
• a displacement aperture 50 cf. Fig. 12 to Fig. 14 provides for a channel through which displaced liquid from the liquid compartment 28 may flow.
• the first tubular element 21 moves along the insertion path, water in the second tubular element 23 is displaced out through a displacement aperture 50 arranged between the two tubular elements 21 , 23.
• the displacement aperture is positioned in the annulus between the first tubular element 21 and the second tubular element 23, and is indicated in the top views of Fig. 12 to Fig. 14.
• the first tubular element 21 comprises an inner aperture boundary in the form of a split ring 35.
• the split ring 35 abuts an inwardly facing internal face 37 of the second tubular element 23.
• Recessed in this internal face 37 is an outer aperture boundary in the form of a plurality of boundary slots 39.
• the boundary slots 39 each exhibits a recessed face 40.
• the displacement aperture 50 is in this embodiment between the split ring 35 and the recessed face 40 of the boundary slots 39.
• the split ring 35 will be biased towards the internal face 37, or at least exhibit only a small clearance, if any, between it and the internal face 37.
• Fig. 9 to Fig. 1 1 show the insertion of the first tubular element 21 into the second tubular element 23 with perspective cross section views showing only a segment of the two tubular elements 21 , 23 and the split ring 35.
• the inner aperture boundary in the form of the split ring 35 is at a start position of the insertion path, in which it faces the upper portion of the outer aperture boundary in the form of the boundary slots 39.
• the split ring 35 is at an intermediate position of the insertion path, while in Fig. 1 1 it is shown at an end position. In the end position, the abutting face 25 of the first tubular element 21 has landed on the landing face 27 of the second tubular element 23.
• the boundary slots 39 exhibit, in addition to the recessed faces 40, side faces 41.
• the two side faces 41 of each boundary slot 39 exhibit an inclination with respect to each other. Their mutual tangential distance decreases towards the end position. That is, at the position of the split ring 35, the mutual distance between the two side faces 41 becomes less as the split ring 35 moves towards the end position.
• this is also illustrated with the top cross section views of Fig. 12 to Fig. 14.
• the drawings in Fig. 12 to Fig. 14 illustrate the displacement aperture 50 area in the situations shown in Fig. 9 to Fig. 1 1 , respectively.
• Fig. 15 is a schematic side view of a portion of the split ring 35 and a lower portion of the boundary slot 39 when in an end position.
• the lowermost portion of the boundary slot 39 extends beyond the lowermost part of the split ring 35. This feature is to prevent a hydrostatic locking effect at the end position.
• the displacement aperture 50 will be present at all times, although only with a small area in the end position.
• the inner aperture boundary could also be constituted by the body of the first tubular element 21 itself.
• split ring 35 is advantageous, as one may replace it with a ring of other diameter, thereby adapting the dampening effect to the embodiment in question.
• the split ring 35 is maintained in its axial position with respect to the first tubular element 21 by appropriate means.
• the split ring could also be replaced with a continuous ring, which would also be appropriate for replacement.
• Fig. 16 is a perspective view showing an embodiment of a dampening assembly 200 corresponding to the one shown with reference to Fig. 6 to Fig. 15, however with the boundary slots 39' arranged on an outwardly facing external face 37' of the first tubular element 21.
• the displacement aperture will also become reduced during insertion towards the end position of the insertion path, i.e. towards the landed position.
• Fig. 17 is a cross section perspective view of another embodiment of a dampen- ing assembly 300 according to the present invention.
• the assembly shown in Fig. 17 comprises a first and second tubular element 21 , 23.
• the first tubular element 21 is provided with the seal 26 which is adapted to seal against an inwardly facing face or bore of the second tubular element 23.
• a split ring 36 is arranged on the first tubular element 21 .
• the split ring 36 in this embodiment has a plurality of cutouts 45 along its outer perimeter.
• the liquid containing liquid compartment 28 is located.
• the internal face 37 of the previous embodiment has an axial extension, i.e. parallel with an axial axis of the two tubular elements 21 , 23, the second tubular element 23 shown in Fig. 17 exhibits a tapered internal face 38.
• the split ring 36 abuts this tapered internal face 38.
• the tapered internal face 38 exhibits a tapered inwardly facing surface which exhibits a smaller diameter towards the end position. That is, as the split ring 36 is moved axially along the insertion path towards the end position (landed position), the diameter of the split ring 36 is reduced as it is forced radially inwards by the facing and abutting tapered internal face 38.
• Fig. 18 to Fig. 21 are perspective cross section views showing the first tubular element 21 in the process of entering the second tubular element 23, and moving along the insertion path until landing at the end position (Fig. 21 ).
• Fig. 22 to Fig. 24 show a segment of the split ring 36 and its cutouts 45 in positions corresponding to Fig. 19 to Fig. 21 .
• the cutouts 45 face radially outwards towards the tapered internal face 38.
• Fig. 22 illustrates the entire area of the cutouts 45 for water to flow through when being displaced. That is, the displacement aperture 50 in the upper position is identical to the area of the cutouts 45.
• Fig. 23 illustrates the situation shown in the perspective view of Fig. 20, where the split ring 36 has moved to an intermediate position. In this position the split ring 36 has been forced some distance inwards. In this position approximately half of the cutout area is available for the flow-through of water, while the other half is overlapping an upwardly facing surface of the first tubular element 21 (indicated with the dashed line).
• FIG. 25 The perspective cross section view of Fig. 25 shows an embodiment which is similar to the one described with reference to Fig. 17 to Fig. 24. However, in the embodiment shown in Fig. 25 the split ring 36 is attached to the second tubular element 23. The cutouts 45 face inwards towards the circular body of the first tubular element 21 . When the first tubular element 21 is inserted into the second tubular element 23, the split ring 36 is forced radially outwards, thereby increasing its diameter. As this takes place the area of the cutouts 45 are gradually covered with the surface of the second tubular element 23.
• Fig. 26 is a perspective view of yet another embodiment of a dampening assembly 500 according to the present invention. Its function is described with reference to Fig. 27 and Fig. 28.
• the first tubular element 21 is shown in an intermediate position, partially inserted into the second tubular element 23.
• the seal 26 on a lower portion of the first tubular element 21 has entered a bore of the second tubular element 23, against which it seals.
• the abutting face 25 is adapted to land on the landing face 27 of the second tubular element 23.
• Above the abutting face 25 the first tubular element 21 has an inner aperture boundary in the form of a tapered boundary face 34.
• the tapered boundary face 34 of the first tubular element 21 faces an outer aperture boundary in the form of an end edge 44 of the inwardly facing internal face 37 of the second tubular element 23.
• the end edge 44 substantially abuts the tapered boundary face 34 so that the displacement aperture 50 is substantially non existent.
• this gap which is the displacement aperture 50, becomes gradually reduced as the first tubular element 21 moves towards the end position.
• the dampening effect increases along the insertion path.
• the displacement aperture 50 is an annular aperture.
• the tapered boundary face 34 could indeed be arranged as an inwardly facing surface of the second tubular element 23, and the end edge 44 could then be arranged on the first tubular element 21 .
• the tapering would then however be in the opposite direction than the tapering shown in Fig. 27 and Fig. 28, and the end edge would be at a lower portion of the tapered surface.
• the displacement aperture 50 needs not be approximately zero at the end position. There may indeed be a substantial area of the displacement aperture 50, which however will ensure a desired dampening effect that reduces wear and damage. Such an area will be chosen by the person skilled in the art according to need.
• a particular feature of using a tapered outer or inner circular surface in such way that the inclination of the surface gradually reduces the displacement aperture, is that not only is an increased dampening effect achieved along the insertion path, but one can also obtain an increase of such an increase. That is, the second derivative of the area of the displacement aperture is not zero along the insertion path. This applies to a straight tapered surface (i.e. a tapered circular shape having a cross section showing straight outer surfaces).
• the liquid (water) to be displaced is confined in an annular liquid compartment 28.
• the annular liquid compartment 28 is located radially between the first and second tubular element 21 , 23 and axially between the abutting face 25 and the landing face 27.
• an advantage is that one may replace the ring with another ring having other design, in order to alter the dampening effect. This also applies for embodiments where use of a continuous ring is possible.
• a replacement ring having another design could mean a ring having larger or smaller cutouts, another shape of the cutouts, or a ring having larger or smaller diameter.

Landscapes

• Engineering & Computer Science (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Fluid Mechanics (AREA)
• Environmental & Geological Engineering (AREA)
• Physics & Mathematics (AREA)
• Geochemistry & Mineralogy (AREA)
• General Engineering & Computer Science (AREA)
• Combined Devices Of Dampers And Springs (AREA)
• Earth Drilling (AREA)
• Fluid-Damping Devices (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)
• Ultra Sonic Daignosis Equipment (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=52008407

Family Applications (1)

Country Status (3)

Citations (7)

• 2013
  • 2013-06-03 NO NO20130767A patent/NO336119B1/no unknown
• 2014
  • 2014-05-27 WO PCT/NO2014/050084 patent/WO2014196868A1/en active Application Filing
  • 2014-05-27 GB GB1521869.6A patent/GB2531445B/en active Active

Patent Citations (7)

Also Published As

Similar Documents

Legal Events