WO2011096820A2 - A bend restrictor - Google Patents
A bend restrictor Download PDFInfo
- Publication number
- WO2011096820A2 WO2011096820A2 PCT/NO2011/000041 NO2011000041W WO2011096820A2 WO 2011096820 A2 WO2011096820 A2 WO 2011096820A2 NO 2011000041 W NO2011000041 W NO 2011000041W WO 2011096820 A2 WO2011096820 A2 WO 2011096820A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bend restrictor
- link element
- bend
- link
- guide
- Prior art date
Links
- 230000008878 coupling Effects 0.000 claims abstract description 10
- 238000010168 coupling process Methods 0.000 claims abstract description 10
- 238000005859 coupling reaction Methods 0.000 claims abstract description 10
- 230000004323 axial length Effects 0.000 claims description 10
- 239000002131 composite material Substances 0.000 claims description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 238000003780 insertion Methods 0.000 claims description 3
- 230000037431 insertion Effects 0.000 claims description 3
- 238000009434 installation Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G3/00—Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles
- H02G3/02—Details
- H02G3/04—Protective tubing or conduits, e.g. cable ladders or cable troughs
- H02G3/0462—Tubings, i.e. having a closed section
- H02G3/0475—Tubings, i.e. having a closed section formed by a succession of articulated units
-
- 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
- E21B19/22—Handling reeled pipe or rod units, e.g. flexible drilling pipes
-
- 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
- E21B19/24—Guiding or centralising devices for drilling rods or pipes
-
- 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
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L57/00—Protection of pipes or objects of similar shape against external or internal damage or wear
- F16L57/02—Protection of pipes or objects of similar shape against external or internal damage or wear against cracking or buckling
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G9/00—Installations of electric cables or lines in or on the ground or water
- H02G9/02—Installations of electric cables or lines in or on the ground or water laid directly in or on the ground, river-bed or sea-bottom; Coverings therefor, e.g. tile
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G9/00—Installations of electric cables or lines in or on the ground or water
- H02G9/06—Installations of electric cables or lines in or on the ground or water in underground tubes or conduits; Tubes or conduits therefor
- H02G9/065—Longitudinally split tubes or conduits therefor
Definitions
- the invention relates to bend restrictors for use with flexible elongate members, as defined in the introduction to claim 1.
- Known bend restrictors serve to receive some form of pliable flexible elongate member, for example a cable, pipe, umbilical, marine riser etc., and to prevent it from adopting an excessively small radius of curvature.
- the state of the art includes GB 2269274, which describes a bend restrictor for a pliable subsea telecommunications cable.
- a segmented bend restrictor surrounding the cable serves to prevent it from being excessively tightly bent.
- the bend restrictor disclosed in the mentioned publication comprises a number of "housing members" each having a through-going bore to receive the cable and being joined to identically formed neighbouring housing members via universal joints of a ball-and- socket type.
- EP 0 197 546 B l which describes a flexible supporting sheath for cables, hoses and the like (carrying electric signals, gas, water, etc.) which are connected between e.g. a fixed installation and a movable object (e.g. a robot).
- the supporting sheath comprises a ball-and-socket connection, where the sockets are made up of two half-links arranged to face each other, and snapped together by a tongue-and-groove coupling. It is described how the coupled half links easily can be disconnected by the insertion of the tip of a screwdriver into the groove.
- bend restriction is achieved by abutment of slanted end faces of neighbouring housing members, which limit the angular displacement of one housing relative to another.
- Known bend restrictors are designed for cables, hoses, and the like, that are easily flexible (i.e. having low inherent stiffness) and that are more or less stationary with respect to the bend restrictor which supports them (although the bend angle may be varying, due to the movement of a robot, or similar, to which the cable or hose is connected).
- a composite rod cable is especially beneficial.
- This type of cable comprises one or more leads (e.g. metal power leads, and fibre-optic leads) embedded in a carbon rod, and are normally stored on large reels, off of which it is spooled into and out of a downhole location in a borehole.
- These relatively stiff composite rod cables may be of considerable length (e.g. around 7000 metres) and is moved into and out of the borehole by an injector mechanism located on the wellhead.
- Composite rod cables typically handle tensile stresses well, but are susceptible to buckling and fracturing when subjected to compressive and transverse forces. When retrieving the cable from the borehole, and re-winding it back onto the spool, the rod cable is literally pushed by the injector mechanism, thus generating undesirable compressive forces in the rod.
- a bend restrictor for an elongate flexible element which is being moved through the bend restrictor comprising at least two guide elements and a link element, each said guide element comprising two spherical portions separated by a central portion, said spherical portions being configured for coupling to respective spherical portions in said link element in a manner allowing angular movement between the respective guide elements and between the link element, and wherein each guide element comprises first stop means for abutment against respective second stop means on the link element, and wherein the link element comprises two halves, the bend restrictor further being characterized by retainer means and locking means for holding the halves together and securing said coupling between the guide elements and link element.
- the first stop means comprises a ridge-shaped structure, arranged circumferentially with respect to a guide element central axis, thus forming a circumferential groove
- the second stop means comprises an abutment structure arranged circumferentially with respect to a link element central axis, said groove and abutment structure having complimentary shapes.
- the link element comprises a second stop means in a region of each end of the link element, and the guide element comprises a first stop means in a region between each spherical portion and the central portion.
- the guide element comprises conveniently convex spherical portions, and the link element comprises concave spherical portions, and the coupling is of a ball-and- socket type.
- the axial length of the link element is greater than or equal to twice the axial length of a spherical portion, and the axial length of the central portion is greater than the axial length of the link element.
- the guide elements and the link member preferably comprise tubular elements and have respective communicating passageways for accommodating said elongate flexible element.
- the link element comprises of two halves
- the bend restrictor further comprises retainer means and locking means, whereby said halves are clamped together, securing said coupling between the guide elements and the link element.
- the bend restrictor comprises friction means for controlling the bend restrictor rigidity, for example in the form of an o-ring arranged in a recessed section of the spherical portion.
- the invented bend restrictor may conveniently be used for restricting the bend radius of a pliable but semi-rigid cable, such as a carbon composite cable.
- Figure 1 is a side view of an embodiment of the bend restrictor according to the invention.
- Figure 2 is a sectional side view, along the central axis, of the embodiment illustrated in figure 1 , rotated 90° with respect to the central axes;
- Figure 3 is an enlarged view of the region labelled "A" in figure 2;
- Figure 4a is an enlarged view of the region labelled "B" in figures 2 and 3;
- Figure 4b is an enlarged view of the region labelled "C” in figures 2 and 3 ;
- Figure 5 is a perspective view of a half of an embodiment of a link element, showing one of two virtually identical halves;
- Figure 6 is a sectional side view, along the central axis, of the link element half illustrated in figure 5;
- Figure 7 is an enlarged view of the region labelled "D" in figure 6;
- Figure 8 shows the link element half illustrated in figures 5 and 6, from one end
- Figure 9 is a schematic illustration of a typical cable installation
- Figure 10 is an enlarged view of the region labelled "E" in figure 9;
- Figure 1 1 is a sectional side view of an embodiment of the invention, showing two guide elements, a link element, and a connection element.
- the bend restrictor according to the invention comprises at least two guide elements 2, connected by a link element 6.
- Figure 1 illustrates one such configuration, and also illustrates how a further guide element (not shown) may be connected via the link element in the right-hand side of the figure.
- a bend restrictor may be designed to comprise a plurality of guide elements 2, linked in an end-to-end relationship via respective link elements 6, depending on the applicable
- Each guide element 2 comprises a tubular element having a central axis CLI and a passageway 3 for a cable or similar.
- An elastic composite rod cable 4 having a high stiffness is show to be moving back and forth within the guide elements and link element, illustrated by the double arrow marked "M" in figure 1.
- the illustrated guide element has two convex spherical portions 10, one in each end, separated by a central section 9, for coupling to respective concave spherical portions 14 in the link element 6.
- this ball-and-socket connection allows angular movement between the respective guide elements 2 and the link element 6.
- the guide element 2 further comprises a ridge-shaped structure 1 la, arranged circumferentially with respect to the central axis CLI, thus forming a circumferential groove l ib.
- the ridges 1 la and grooves 1 lb are arranged in the transition regions between the spherical portions 10 and the central portion 9.
- the angle ⁇ as well as the depth of the groove 1 lb, determine - in interaction with the link element 6 - the minimum permitted radius for the bend restrictor.
- ⁇ in the order of 5°.
- Each spherical portion 10 comprises a circumferential groove 1 (figure 1 ) into which an o-ring 5 is placed when the guide elements and link element are assembled (figure 2).
- the o-rings 5 generate friction against the concave spherical portions 14 in the link element 6, thus giving a certain degree of rigidity (resistance to movement) in the ball-and-socket connection.
- the friction-generating o-rings 5 therefore provide a stiffening factor to the bend restrictor as a whole.
- the stiffness (or resistance to movement) of the bend restrictor may thus be controlled by selecting o-rings that provides the desired amount of friction.
- Figure 2 illustrates how the axial length L of the central portion 9 is greater than the axial lengths L 2 of the spherical elements 10, preferably in a relationship where Li ⁇ 2L 2 .
- Figure 2 and figure 3 also illustrate how the cable 4 is bearing against the one (lower) side of the bend restrictor when being inserted into the well (reference character "I") and - with a dotted line - how the cable 4' is bearing against the opposite (upper) side of the bend restrictor when being pushed back onto a reel (see figure 9) (reference character "B")
- the link element 6 comprises an abutment structure 18 arranged at each end, circumferentially with respect to a central axis CL 2 .
- the groove l ib and the abutment structure 18 have complimentary shapes, and the interaction between the abutment structure 18 and the groove 1 lb thus determines the minimum permitted radius for the bend restrictor.
- the link element 6 comprises two identical halves 6a, 6b which are secured by a retainer ring 8 which abuts against a corresponding face 12 on the link element halves, thus keeping the link element halves together even when they are subjected to friction forces generated by the moving cable bearing against the inner walls of the bend restrictor.
- the retainer ring 8 is held in position by a locking ring 17, arranged in a groove 16 on the link element halves.
- Figure 8 also indicates how the connection between the halves may be improved by pegs 19 on one link half, and corresponding holes on the other link half (not shown).
- the bend radius r is also determined by the design of the spherical portions 10, 14, and by the length of the guide element 2, notably the length L] of the central section 9.
- the central section 9 may be designed such that the length L ⁇ can be varied in the field, e.g. by having the central section 9 comprising two halves joined
- the invented bend restrictor is used in connection with feeding a composite rod cable 4 into and out of a borehole.
- This is illustrated schematically in figure 9, showing a spooling unit (reel) 23 for the cable 4, and an injector head 22 by means of which the cables is pulled (for cable insertion) and pushed (for cable retrieval).
- the injector head 22, which is commonly used for this purpose, comprises driving means (belts, etc.) for feeding the cable and is connected to e.g. a tubular (not shown) leading into the borehole.
- the invented bend restrictor is typically used in the regions defined by dotted-line boxes labelled "T", ensuring that the cable is aligned with the injector head 22 as it is pulled into the injector head.
- Figure 10 is an enlarged view of the injector head connection unit 24, and also shows the cable 4 and the cable head 4a (the bend restrictor is not shown, for clarity of illustration).
- Figure 1 1 shows the end of the bend restrictor, where it is connected to the injector head by connecting the end piece 20 to the connection unit 24 (figure 10).
- the figures show how the diameter dj, of the cable head 4a is nearly as great as the diameter d g of the guide element 2 (figure 2), and also show the diameter d c of the cable 4 in relation to those diameters.
- the bend restrictor according to the invention is especially suitable for use with semi-rigid, carbon rod-type cables, and where the diameter d g of the guide element is much greater than the diameter d c of the cable, for example a telecommunications cable, control cable, etc., and with a light to large inherent stiffness.
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- General Life Sciences & Earth Sciences (AREA)
- Fluid Mechanics (AREA)
- Environmental & Geological Engineering (AREA)
- Physics & Mathematics (AREA)
- Geochemistry & Mineralogy (AREA)
- General Engineering & Computer Science (AREA)
- Architecture (AREA)
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Abstract
A bend restrictor for an elongate flexible element, such as a cable, comprising at least two guide elements (2) and a link element (6), each said guide element (2) comprising spherical portions (10) for coupling to respective spherical portions (14) in said link element (6) in a manner allowing angular movement between the respective guide elements (2) and between the link element (6). The bend restrictor comprises first stop means (11a, 11b) on each guide element (2), for abutment against respective second stop means (18) on the link element (6).
Description
A bend restrictor
Field of the invention
The invention relates to bend restrictors for use with flexible elongate members, as defined in the introduction to claim 1.
Background of the invention
Known bend restrictors serve to receive some form of pliable flexible elongate member, for example a cable, pipe, umbilical, marine riser etc., and to prevent it from adopting an excessively small radius of curvature.
The state of the art includes GB 2269274, which describes a bend restrictor for a pliable subsea telecommunications cable. A segmented bend restrictor surrounding the cable serves to prevent it from being excessively tightly bent. The bend restrictor disclosed in the mentioned publication comprises a number of "housing members" each having a through-going bore to receive the cable and being joined to identically formed neighbouring housing members via universal joints of a ball-and- socket type.
The state of the art also includes EP 0 197 546 B l , which describes a flexible supporting sheath for cables, hoses and the like (carrying electric signals, gas, water, etc.) which are connected between e.g. a fixed installation and a movable object (e.g. a robot). The supporting sheath comprises a ball-and-socket connection, where the sockets are made up of two half-links arranged to face each other, and snapped together by a tongue-and-groove coupling. It is described how the coupled half links easily can be disconnected by the insertion of the tip of a screwdriver into the groove.
In the state of the art, bend restriction is achieved by abutment of slanted end faces of neighbouring housing members, which limit the angular displacement of one housing relative to another. Known bend restrictors are designed for cables, hoses, and the like, that are easily flexible (i.e. having low inherent stiffness) and that are more or less stationary with respect to the bend restrictor which supports them (although the bend angle may be varying, due to the movement of a robot, or similar, to which the cable or hose is connected).
In certain applications, such as the control and monitoring of instruments and apparatuses in subterranean boreholes in the oil and gas industry, a composite rod cable is especially beneficial. This type of cable comprises one or more leads (e.g. metal power leads, and fibre-optic leads) embedded in a carbon rod, and are normally stored on large reels, off of which it is spooled into and out of a downhole
location in a borehole. These relatively stiff composite rod cables may be of considerable length (e.g. around 7000 metres) and is moved into and out of the borehole by an injector mechanism located on the wellhead. Composite rod cables typically handle tensile stresses well, but are susceptible to buckling and fracturing when subjected to compressive and transverse forces. When retrieving the cable from the borehole, and re-winding it back onto the spool, the rod cable is literally pushed by the injector mechanism, thus generating undesirable compressive forces in the rod.
It is therefore a need for a device for controlling the bending of such stiff (but flexible) composite rod cable when the cable is moving within the device and as it is being spooled off of and onto the reel, in particular when the cable is retrieved from the borehole and spooled back onto the reel.
Summary of the invention
The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.
It is thus provided a bend restrictor for an elongate flexible element which is being moved through the bend restrictor, comprising at least two guide elements and a link element, each said guide element comprising two spherical portions separated by a central portion, said spherical portions being configured for coupling to respective spherical portions in said link element in a manner allowing angular movement between the respective guide elements and between the link element, and wherein each guide element comprises first stop means for abutment against respective second stop means on the link element, and wherein the link element comprises two halves, the bend restrictor further being characterized by retainer means and locking means for holding the halves together and securing said coupling between the guide elements and link element.
In one embodiment, the first stop means comprises a ridge-shaped structure, arranged circumferentially with respect to a guide element central axis, thus forming a circumferential groove, and the second stop means comprises an abutment structure arranged circumferentially with respect to a link element central axis, said groove and abutment structure having complimentary shapes.
In one embodiment, the link element comprises a second stop means in a region of each end of the link element, and the guide element comprises a first stop means in a region between each spherical portion and the central portion.
The guide element comprises conveniently convex spherical portions, and the link element comprises concave spherical portions, and the coupling is of a ball-and- socket type.
In one embodiment, the axial length of the link element is greater than or equal to twice the axial length of a spherical portion, and the axial length of the central portion is greater than the axial length of the link element.
The guide elements and the link member preferably comprise tubular elements and have respective communicating passageways for accommodating said elongate flexible element.
In one embodiment, the link element comprises of two halves, and the bend restrictor further comprises retainer means and locking means, whereby said halves are clamped together, securing said coupling between the guide elements and the link element.
In one embodiment, the bend restrictor comprises friction means for controlling the bend restrictor rigidity, for example in the form of an o-ring arranged in a recessed section of the spherical portion.
The invented bend restrictor may conveniently be used for restricting the bend radius of a pliable but semi-rigid cable, such as a carbon composite cable.
Brief description of the drawings
These and other characteristics of the invention will be clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein:
Figure 1 is a side view of an embodiment of the bend restrictor according to the invention;
Figure 2 is a sectional side view, along the central axis, of the embodiment illustrated in figure 1 , rotated 90° with respect to the central axes;
Figure 3 is an enlarged view of the region labelled "A" in figure 2;
Figure 4a is an enlarged view of the region labelled "B" in figures 2 and 3; Figure 4b is an enlarged view of the region labelled "C" in figures 2 and 3 ;
Figure 5 is a perspective view of a half of an embodiment of a link element, showing one of two virtually identical halves;
Figure 6 is a sectional side view, along the central axis, of the link element half illustrated in figure 5;
Figure 7 is an enlarged view of the region labelled "D" in figure 6;
Figure 8 shows the link element half illustrated in figures 5 and 6, from one end;
Figure 9 is a schematic illustration of a typical cable installation
arrangement, incorporating the bend restrictor according to the invention;
Figure 10 is an enlarged view of the region labelled "E" in figure 9; and
Figure 1 1 is a sectional side view of an embodiment of the invention, showing two guide elements, a link element, and a connection element.
Detailed description of a preferential embodiment
The bend restrictor according to the invention comprises at least two guide elements 2, connected by a link element 6. Figure 1 illustrates one such configuration, and also illustrates how a further guide element (not shown) may be connected via the link element in the right-hand side of the figure. Thus, a bend restrictor may be designed to comprise a plurality of guide elements 2, linked in an end-to-end relationship via respective link elements 6, depending on the applicable
requirements.
Each guide element 2 comprises a tubular element having a central axis CLI and a passageway 3 for a cable or similar. An elastic composite rod cable 4 having a high stiffness, is show to be moving back and forth within the guide elements and link element, illustrated by the double arrow marked "M" in figure 1. The illustrated guide element has two convex spherical portions 10, one in each end, separated by a central section 9, for coupling to respective concave spherical portions 14 in the link element 6. Thus, this ball-and-socket connection allows angular movement between the respective guide elements 2 and the link element 6.
The guide element 2 further comprises a ridge-shaped structure 1 la, arranged circumferentially with respect to the central axis CLI, thus forming a circumferential groove l ib. The ridges 1 la and grooves 1 lb are arranged in the transition regions between the spherical portions 10 and the central portion 9. Referring to figure 3, the angle γ, as well as the depth of the groove 1 lb, determine - in interaction with the link element 6 - the minimum permitted radius for the bend restrictor. In the illustrated embodiment, γ in the order of 5°.
Each spherical portion 10 comprises a circumferential groove 1 (figure 1 ) into which an o-ring 5 is placed when the guide elements and link element are assembled (figure 2). The o-rings 5 generate friction against the concave spherical portions 14 in the link element 6, thus giving a certain degree of rigidity (resistance to movement) in the ball-and-socket connection. The friction-generating o-rings 5 therefore provide a stiffening factor to the bend restrictor as a whole. The stiffness (or resistance to movement) of the bend restrictor may thus be controlled by selecting o-rings that provides the desired amount of friction.
Figure 2 illustrates how the axial length L of the central portion 9 is greater than the axial lengths L2 of the spherical elements 10, preferably in a relationship where Li≥ 2L2. Figure 2 and figure 3 also illustrate how the cable 4 is bearing against the one (lower) side of the bend restrictor when being inserted into the well (reference character "I") and - with a dotted line - how the cable 4' is bearing against the opposite (upper) side of the bend restrictor when being pushed back onto a reel (see figure 9) (reference character "B")
The link element 6 comprises an abutment structure 18 arranged at each end, circumferentially with respect to a central axis CL2. The groove l ib and the abutment structure 18 have complimentary shapes, and the interaction between the abutment structure 18 and the groove 1 lb thus determines the minimum permitted radius for the bend restrictor.
The link element 6 comprises two identical halves 6a, 6b which are secured by a retainer ring 8 which abuts against a corresponding face 12 on the link element halves, thus keeping the link element halves together even when they are subjected to friction forces generated by the moving cable bearing against the inner walls of the bend restrictor. The retainer ring 8 is held in position by a locking ring 17, arranged in a groove 16 on the link element halves. Figure 8 also indicates how the connection between the halves may be improved by pegs 19 on one link half, and corresponding holes on the other link half (not shown).
The bend radius r is also determined by the design of the spherical portions 10, 14, and by the length of the guide element 2, notably the length L] of the central section 9. The central section 9 may be designed such that the length L\ can be varied in the field, e.g. by having the central section 9 comprising two halves joined
telescopically or by threads (not shown).
The invented bend restrictor is used in connection with feeding a composite rod cable 4 into and out of a borehole. This is illustrated schematically in figure 9, showing a spooling unit (reel) 23 for the cable 4, and an injector head 22 by means of which the cables is pulled (for cable insertion) and pushed (for cable retrieval). The injector head 22, which is commonly used for this purpose, comprises driving means (belts, etc.) for feeding the cable and is connected to e.g. a tubular (not
shown) leading into the borehole. The invented bend restrictor is typically used in the regions defined by dotted-line boxes labelled "T", ensuring that the cable is aligned with the injector head 22 as it is pulled into the injector head.
Figure 10 is an enlarged view of the injector head connection unit 24, and also shows the cable 4 and the cable head 4a (the bend restrictor is not shown, for clarity of illustration). Figure 1 1 shows the end of the bend restrictor, where it is connected to the injector head by connecting the end piece 20 to the connection unit 24 (figure 10). The figures show how the diameter dj, of the cable head 4a is nearly as great as the diameter dg of the guide element 2 (figure 2), and also show the diameter dc of the cable 4 in relation to those diameters.
The bend restrictor according to the invention is especially suitable for use with semi-rigid, carbon rod-type cables, and where the diameter dg of the guide element is much greater than the diameter dc of the cable, for example a telecommunications cable, control cable, etc., and with a light to large inherent stiffness.
Claims
1. A bend restrictor for an elongate flexible element (4) which is being moved through the bend restrictor, comprising at least two guide elements (2) and a link element (6), each said guide element (2) comprising two spherical portions (10) separated by a central portion (9), said spherical portions being configured for coupling to respective spherical portions (14) in said link element (6) in a manner allowing angular movement between the respective guide elements (2) and between the link element (6), and wherein each guide element (2) comprises first stop means (1 1a, l ib) for abutment against respective second stop means (18) on the link element (6), and wherein the link element (6) comprises two halves (6a, 6b), the bend restrictor further being characterized by
retainer means (8) and locking means (16, 17) for holding the halves (6a, 6b) together and securing said coupling between the guide elements and the link element.
2. The bend restrictor of claim 1 , wherein the first stop means (1 1a, l ib) comprises a ridge-shaped structure (1 1a), arranged circumferentially with respect to a guide element central axis (CLI), thus forming a circumferential groove (1 lb), and wherein the second stop means (18) comprises an abutment structure arranged circumferentially with respect to a link element central axis (CL2), said groove (l ib) and abutment structure (18) having complimentary shapes.
3. The bend restrictor of claim 1 or claim 2, wherein the link element (6) comprises a second stop means (18) in a region of each end of the link element.
4. The bend restrictor of any one of claims 1 - 3, wherein the guide element (2) comprises a first stop means (1 l a,b) in a region between each spherical portion (10) and the central portion (9).
5. The bend restrictor of any one of claims 1 - 4, wherein the guide element (2) comprises convex spherical portions (10), and the link element (6) comprises concave spherical portions (14), and the coupling is of a ball-and-socket type.
6. The bend restrictor of any one of claims 1 - 5, wherein the axial length (L3) of the link element (6) is greater than or equal to twice the axial length (L2) of a spherical portion (10), and the axial length (L of the central portion (9) is greater than the axial length (L3) of the link element (6).
7. The bend restrictor of any one of claims 1 - 6, wherein the guide elements and the link member comprise tubular elements and have respective communicating passageways (3, 19) for accommodating said elongate flexible element.
8. The bend restrictor of any one of claims 1 - 7, wherein the retainer means (8) comprises a ring configured for clamping the halves (6a, 6b) together, and the locking means comprises a groove (16) on the halves and a locking ring (17) for insertion into the groove, whereby the ring (8) is held in position by the locking ring which is inserted in the groove.
9. The bend restrictor of any one of claims 1 - 8, further comprising friction means (5) for controlling the bend restrictor rigidity.
10. The bend restrictor of claim 9, wherein the friction means comprises an o- ring (5) arranged in a recessed section (1) of the spherical portion (10).
1 1. Use of the bend restrictor as specified by any one of claims 1 - 10, for restricting the bend radius of a pliable but semi-rigid cable (4), such as a carbon composite rod cable.
12. Use of the bend restrictor as specified by any one of claims 1 - 10, for deploying a composite rod cable (4) between a spooling unit (23), into an injector head (22) which is connected to a borehole.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NO20100174A NO20100174A1 (en) | 2010-02-03 | 2010-02-03 | Boyingsbegrenser |
NO20100174 | 2010-02-03 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2011096820A2 true WO2011096820A2 (en) | 2011-08-11 |
WO2011096820A3 WO2011096820A3 (en) | 2012-05-31 |
Family
ID=44168283
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/NO2011/000041 WO2011096820A2 (en) | 2010-02-03 | 2011-02-02 | A bend restrictor |
Country Status (2)
Country | Link |
---|---|
NO (1) | NO20100174A1 (en) |
WO (1) | WO2011096820A2 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013095157A2 (en) | 2011-12-23 | 2013-06-27 | C6 Technologies As | Flexible routing device for well intervention |
NO333887B1 (en) * | 2011-12-23 | 2013-10-14 | C6 Technologies As | A bend limiter that can be traversed and traversed by a continuous well intervention string |
WO2014109642A1 (en) | 2013-01-09 | 2014-07-17 | C6 Technologies As | A well intervention cable bending restriction for a rigid resilient rod-shaped intervention cable |
WO2014163508A1 (en) * | 2013-03-11 | 2014-10-09 | C6 Technologies As | A petroleum well injection system for an intervention cable with a well tool run into or out of a well during a well operation |
WO2015054046A1 (en) * | 2013-10-11 | 2015-04-16 | Antelope Oil Tool & Mfg. Co., Llc | Centralizer preconditioning and testing apparatus and method |
WO2017182781A1 (en) * | 2016-04-21 | 2017-10-26 | Advanced Insulation Plc | Guide apparatus |
US9889907B2 (en) | 2015-03-26 | 2018-02-13 | Cgg Services Sas | Quick mount cable-protecting device usable in marine surveys |
US10787866B2 (en) | 2015-11-18 | 2020-09-29 | Halliburton Energy Services, Inc. | Segmented bend-limiter for slickline rope sockets and cable-heads |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NO20100666A1 (en) | 2010-05-07 | 2011-11-08 | C6 Technologies As | Brake for an elongated element |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0197546B1 (en) | 1985-04-09 | 1989-02-08 | Tsubakimoto Chain Co. | Flexible supporting sheath for cables and the like |
GB2269274A (en) | 1992-07-22 | 1994-02-02 | Orcina Cable Protection Limite | Bend limiter |
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Publication number | Priority date | Publication date | Assignee | Title |
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DE9017373U1 (en) * | 1990-12-22 | 1991-04-18 | LIC Langmatz GmbH, 8100 Garmisch-Partenkirchen | Protective pipe segment for the composition of a protective pipe section for electrical cable |
US6039081A (en) * | 1997-02-12 | 2000-03-21 | Pmi Industries, Inc. | Articulated bend limiter |
DE20305462U1 (en) * | 2003-04-04 | 2003-06-12 | AHMTEC GmbH, 26789 Leer | Protector for cables and pipelines |
GB2435084A (en) * | 2006-02-13 | 2007-08-15 | Crp Group Ltd | Cladding for elongate flexible member |
-
2010
- 2010-02-03 NO NO20100174A patent/NO20100174A1/en not_active Application Discontinuation
-
2011
- 2011-02-02 WO PCT/NO2011/000041 patent/WO2011096820A2/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0197546B1 (en) | 1985-04-09 | 1989-02-08 | Tsubakimoto Chain Co. | Flexible supporting sheath for cables and the like |
GB2269274A (en) | 1992-07-22 | 1994-02-02 | Orcina Cable Protection Limite | Bend limiter |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013095157A2 (en) | 2011-12-23 | 2013-06-27 | C6 Technologies As | Flexible routing device for well intervention |
NO333887B1 (en) * | 2011-12-23 | 2013-10-14 | C6 Technologies As | A bend limiter that can be traversed and traversed by a continuous well intervention string |
WO2013095157A3 (en) * | 2011-12-23 | 2014-01-03 | C6 Technologies As | Flexible routing device for well intervention |
WO2014109642A1 (en) | 2013-01-09 | 2014-07-17 | C6 Technologies As | A well intervention cable bending restriction for a rigid resilient rod-shaped intervention cable |
US9932782B2 (en) | 2013-01-09 | 2018-04-03 | C6 Technologies As | Well intervention cable bending restriction for a rigid resilient rod-shaped intervention cable |
US9458684B2 (en) | 2013-03-11 | 2016-10-04 | C6 Technologies As | Petroleum well injection system for an intervention cable with a well tool run into or out of a well during a well operation |
WO2014163508A1 (en) * | 2013-03-11 | 2014-10-09 | C6 Technologies As | A petroleum well injection system for an intervention cable with a well tool run into or out of a well during a well operation |
WO2015054046A1 (en) * | 2013-10-11 | 2015-04-16 | Antelope Oil Tool & Mfg. Co., Llc | Centralizer preconditioning and testing apparatus and method |
US9611705B2 (en) | 2013-10-11 | 2017-04-04 | Antelope Oil Tool & Mfg. Co. | Centralizer preconditioning and testing apparatus and method |
US9889907B2 (en) | 2015-03-26 | 2018-02-13 | Cgg Services Sas | Quick mount cable-protecting device usable in marine surveys |
US10787866B2 (en) | 2015-11-18 | 2020-09-29 | Halliburton Energy Services, Inc. | Segmented bend-limiter for slickline rope sockets and cable-heads |
WO2017182781A1 (en) * | 2016-04-21 | 2017-10-26 | Advanced Insulation Plc | Guide apparatus |
US10844992B2 (en) | 2016-04-21 | 2020-11-24 | Advanced Insulation Limited | Guide apparatus |
Also Published As
Publication number | Publication date |
---|---|
WO2011096820A3 (en) | 2012-05-31 |
NO20100174A1 (en) | 2011-08-04 |
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