PIPE INJECTORS AND METHODS OF INTRODUCING TUBING INTO OR REMOVING IT FROM A WELL BORE

Abstract

A pipe injector assembly is disclosed, comprising: a pipe injector that includes at least three tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are laterally displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the lateral spacing between the drive components is increased to permit the passage of a coupling of the tubing. A pipe injector assembly is also disclosed, comprising: a pipe injector that includes at least two tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of a coupling of the tubing; and a set of tubing slips that are laterally displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the lateral spacing between the tubing slips is increased to permit the passage of the coupling; in which the pipe injector is displaceable longitudinally relative to the set of tubing slips.

Description

TECHNICAL FIELD

This document relates to pressurised well bores. More particularly it relates to a method of introducing tubing into or removing it from a well bore. It further relates to a pipe injector assembly suitable for use in the method.

BACKGROUND

Introducing tubing into, or removing tubing from, a well bore under pressure requires that the tubing be gripped at all times, in order to prevent the tubing from being blown out of the well. Further, the tubing may require the same gripping after the weight of the tubing in the well has surpassed the pressure of the well, in order to prevent the tubing from falling into the well.

Coupled pipe, also known as jointed or collared tubing, incorporates lengths of tubing connected end to end by couplings that have a wider outer diameter than the lengths of tubing themselves. The presence of these couplings makes injection with a conventional coiled tubing chain injector difficult.

SUMMARY

According to an embodiment, there is provided a method of introducing tubing into or removing it from a well bore which includes: displacing tubing into or out of a well bore by a pipe injector having drive components which drivingly engage the tubing, and displacing at least some of the drive components outwardly to permit a coupling in the tubing to pass between the drive components; and once the coupling has passed the pipe injector, displacing the drive components inwardly drivingly to engaging the tubing. The pipe injector may have at least three tubing drive units radially arranged around the tubing, the tubing drive units having the drive components that drivingly engage the tubing.

The Inventor believes that the embodiments of this document will find application particularly though not necessarily exclusively in pressurised well bores.

In an embodiment, the method may include making use of a pipe injector which is relatively displaceable longitudinally, for example relative to the tubing feed direction. Hence, the method may include, when the drive components of the pipe injector are displaced outwardly, displacing the pipe injector longitudinally in a direction opposite to a feed direction of the tubing, and once the drive components have passed the coupling, displacing the drive components inwardly to drivingly engage the tubing. When the drive components are displaced inwardly they drivingly engage the tubing on the opposite side of the coupling. In some embodiments, the pipe injector is displaceable longitudinally relative to a set of tubing slips. These embodiments may further include: displacing the set of tubing slips outwardly and displacing the tubing longitudinally using the pipe injector to permit a coupling in the tubing to pass the set of tubing slips; and displacing the drive components outwardly and gripping the tubing longitudinally using the set of tubing slips to longitudinally displace the drive components relative to the set of tubing slips to permit a coupling in the tubing to pass the drive components.

The pipe injector may be relatively longitudinally displaceable under the influence of a pressurized fluid, typically hydraulically.

The method may include, prior to displacing the drive components outwardly, locking the tubing releasably in position. Locking the tubing releasably in position may include displacing tubing slips into engagement with the tubing. The method may further include, once the drive components of the pipe injector have been displaced inwardly into driving engagement with the tubing, releasing the tubing by displacing the tubing slips out of engagement with the tubing.

In another embodiment of this document, the method may include making use of an upper pipe injector and a lower pipe injector positioned below and longitudinally in register with the upper pipe injector, the method including displacing drive components of one pipe injector outwardly and displacing the tubing longitudinally using the other pipe injector or injector to permit a coupling in the tubing to pass said one pipe injector or injector. Hence, normally, the tubing may be fed into the well bore using both injectors. As a coupling approaches the upper injector, its tube engaging or drive components are displaced outwardly and the tubing is fed into the well by the lower injector. When the coupling has passed the upper injector, its drive components are displaced inwardly drivingly to engage the tubing above the coupling. The tubing drive components of the lower injector are then displaced outwardly permitting the coupling to pass therebetween, after which they are displaced inwardly drivingly to engage the tubing above the coupling. When tubing is being removed from the well bore the reverse procedure will be followed.

According to another embodiment there is provided a pipe injector assembly which includes: at least one pipe injector that includes at least two tubing drive units radially arranged around a feed axis along which tubing is fed, the drive units including drive components that are laterally displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the lateral spacing between the drive components is increased to permit the passage of a coupling connecting lengths of tubing together therebetween.

The pipe injector may include at least three tubing drive units arranged for example equiangularly around the feed axis.

The drive components may include, associated with each tubing drive unit, a chain guide, an endless feed chain supported on the chain guide and configured in the closed condition drivingly to engage said tubing and a chain drive arrangement. The chain may be contoured and configured to engage the tubing with a friction bite.

In an embodiment of this document, the pipe injector may be relatively displaceable longitudinally, for example relative to the feed axis. In a further embodiment, the assembly may include a support structure and a jacking arrangement whereby the pipe injector is mounted on the support structure. The jacking arrangement may include a plurality of hydraulically actuated piston and cylinder arrangements. In some embodiments, the pipe injector is displaceable longitudinally relative to a set of tubing slips that are displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the spacing between the tubing slips is increased to permit the passage of the coupling.

In another embodiment, the assembly may include an upper pipe injector and a lower pipe injector positioned below and longitudinally in register with the upper injector, the tubing drive units of the upper injector being displaceable from their closed to their open condition independently of those of the lower injector and vice versa.

The assembly may include a sensor arrangement for sensing the position of a coupling in the tubing and for controlling the operation of each pipe injector in response thereto.

These and other aspects of the device and method are set out in the claims, which are incorporated here by reference.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments will now be described with reference to the figures, in which like reference characters denote like elements, by way of example, and in which:

FIGS. 1 to 6 show a side view of a pipe injector assembly in accordance with embodiments of this document illustrating sequentially, the passage of a coupling connecting together lengths of tubing through the pipe injector assembly;

FIGS. 7 to 11 show another pipe injector assembly in accordance with embodiments of this document illustrating sequentially the passage of coupling connecting together lengths of tubing therethrough;

FIG. 12 shows, on an enlarged scale, a side view of part of the pipe injector assembly of FIGS. 7 to 11; and

FIG. 13 shows a sectional elevation of the part of the pipe injector shown in FIG. 12.

FIG. 14 shows another embodiment of a pipe injector assembly with a stationary pipe injector and a movable set of tubing slips.

DETAILED DESCRIPTION

Immaterial modifications may be made to the embodiments described here without departing from what is covered by the claims.

In FIGS. 1 to 6 of the drawings, reference numeral 10 refers generally to a pipe injector assembly in accordance with embodiments of this document.

Referring to FIGS. 2 and 3, a pipe injector assembly 10 is illustrated comprising pipe injector 14. Pipe injector 14 includes at least two tubing drive units 36 radially arranged around a feed axis 18 along which tubing 62 is fed. The tubing drive units 36 have drive components, described in more detail below, which are displaceable between a closed condition (shown in FIG. 2) in which the drive components drivingly engage the tubing 62 and an open condition (shown in FIG. 3) in which the spacing between the drive components is increased to permit the passage of a coupling 70 of the tubing 62.

Referring to FIGS. 1 and 2, in some embodiments the pipe injector assembly 10 includes a set of tubing slips 20 that are laterally displaceable between a closed condition (shown in FIG. 2) in which the tubing slips 20 grip the tubing 62 and an open condition (shown in FIG. 1) in which the lateral spacing between the tubing slips 20 is increased to permit the passage of the coupling 70. In these embodiments, the pipe injector 14 is displaceable longitudinally relative to the set of tubing slips 20.

Referring to FIGS. 1-6, the pipe injector assembly 10 may include a jacking arrangement, generally indicated by reference numeral 16, between the set of tubing slips 20 and the pipe injector 14, whereby the pipe injector 14 is displaceable relative to the tubing slips 20. The pipe injector 14 may also be displaceable relative to a support structure 12 longitudinally relative to a feed axis 18 as described in more detail herebelow.

Mounted below the support structure 12 may be set of tubing slips 20, an annular Bop 22, a single gate 24, an equalise/bleed off spool 26, a single gate Bop 28 and a well head 30. A rotating segment 21 may be positioned between the slips 20 and the Bop 22 that permits the pipe injector 14 to rotate about the axis 18 thereby enabling the assembly to be used for drilling.

The support structure 12 may include three platforms 32 (two of which are visible in FIGS. 1 to 6 of the drawings) which may be displaceable radially in the direction of arrows 34 between a closed condition (shown in FIGS. 1, 2, 5 and 6 of the drawings) and an open condition (shown in FIGS. 3 and 4 of the drawings). The pipe injector 14 may include three tubing drive units, generally indicated by reference numeral 36, one of which may be mounted on each of the platforms 32 by means of a hydraulically actuated piston and cylinder arrangement 38. The three piston and cylinder arrangements 38 together may form the jacking arrangement 16, although other jacking arrangements are possible. The tubing drive units 36 may comprise endless chain tubing drive units as shown. In these embodiments, each drive unit 36 may include one or more drive component, such as a chain guide 40, an endless feed chain 50, and a chain drive arrangement, which may include drive sprocket 44. The chain guide 40 may comprise a pair of spaced apart plates 42 between which a drive sprocket 44 and a pair of idler sprockets 46, 48 are mounted. An idler sprocket may be mounted above the drive sprocket 44, with the idler sprocket 46 mounted horizontally in line with the drive sprocket 44 such that endless chain 50 may be supported on the sprockets, 44, 46, 48 to define a generally triangular path having a vertical run 52, a horizontal run 54 and an inclined run 56. A hydraulic motor 58 (FIG. 11) may be mounted on one of the plates 42 and drivingly connected to the drive sprocket 44 in order to drive the chain 50 in the direction of arrow 60. The motor may be connected to any one of the sprockets. Further, more than one drive motor may be used, e.g. up to three drive motors could be drivingly connected to the sprockets.

A method of introducing tubing 62 into or removing it from well bore 30 may comprise providing set of tubing slips 20 and pipe injector 14 for example as shown in FIGS. 1-6. Referring to FIGS. 5-6, the set of tubing slips 20 may be displaced outwardly and the tubing 62 longitudinally displaced using the pipe injector 14 to permit coupling 70 in the tubing 62 to pass the set of tubing slips 20. In use, in order to inject tubing 62 into a well bore, the drive units 36 may be positioned in their closed condition such that the chains 50 engage the tubing 62 along their vertical runs 52 and feed the tubing along the feed axis 18 in the direction of arrow 66 through the tubing slips 20 which, as shown in FIG. 1 of the drawings, are in their open position, the rotating segment 21, the Bop 22, the gate 24, the bleed off spool 26, the Bop 28 and the well head 30 into the well. Referring to FIGS. 3-4, the drive components may be displaced outwardly and the tubing 62 gripped longitudinally using the set of tubing slips 20 to longitudinally displace the drive components relative to the set of tubing slips 20 to permit coupling 70 in the tubing 62 to pass the drive components of pipe injector 14. As illustrated, this stage may comprise gripping the tubing 62 using the set of tubing slips 20 and longitudinally displacing the drive components of pipe injector 14 relative to the set of tubing slips 20 using jacking arrangement 16 between the tubing drive units and the set of tubing slips. The drive components may be displaced longitudinally relative to a tubing feed direction 66 (shown in FIG. 1).

As described, the pipe injector 14 may be displaceable longitudinally relative to the feed axis 18 when in the open condition. Referring to FIG. 14, an embodiment is illustrated where pipe injector 14 is fixed to the well head 30. In this embodiment, slips 20 are longitudinally displaceable relative to feed axis 18, and may act as a pipe injector that longitudinally displaces tubing 62, for example when pipe injector 14 is not drivingly engaged with tubing 62.

Injector assembly 10 may have a sensor 68 configured to sense the presence of a coupling 70. Sensor 68 may be mounted on top of one of the drive units 36 and configured to sense the presence of a coupling 70 connecting together lengths of tubing. The sensor 68 may be part of a control system configured such that, upon receipt of a signal from the sensor 68 indicative of the presence of a coupling 70 adjacent to the drive units 66, operation of the hydraulic motors 58, is stopped. The tubing slips 20 may be displaced inwardly to grip the tubing 62 (FIG. 2). The drive units 36 may be then displaced radially outwardly by means of openers 72 into their open condition shown in FIG. 3 of the drawings, in which they are clear of the tubing 62. The piston and cylinder arrangements 38 may be then extended in order to displace the drive units 36 past the coupling 70, as shown in FIG. 4 of the drawings. In this position, the drive units may be once again displaced inwardly into driving engagement with the tubing 62 above the coupling 70 and the tubing slips 20 may be displaced into their open position (as illustrated in the FIG. 5 of the drawings). The piston and cylinder arrangements 38 may be returned to their retracted positions, shown in FIG. 6 of the drawings, and the hydraulic motors 58 may be operated in order to drive the chains 50 and feed the tubing into the well bore.

Further, in order to remove tubing from the well bore, the reverse procedure to that described above may be followed. In particular, the drive units 36 may be positioned in their closed condition such that the chains 50 engage the tubing 62 and displace it in a direction opposite to the direction of arrow 66.

A sensor 90 may be mounted below one of the drive units 36 and configured to sense the presence of a coupling 70. The sensor 90 may be part of the control system and accordingly, when a coupling 70 is sensed by the sensor 90, operation of the hydraulic motors 58, is stopped. The piston and cylinder arrangements 38 may be then extended in order to displace the drive units and the tubing into the position shown in FIG. 5 of the drawings. The tubing slips 20 may be displaced to their closed position and the drive units 36 may be displaced radially outwardly by means of the opener 72 into their open condition, shown in FIG. 4 of the drawings, in which they are clear of the tubing 62. The piston and cylinder arrangements 38 may be then retracted in order to displace the drive units 36 past the coupling 70 as shown in FIG. 3 of the drawings. In this position, the drive units may be once again displaced inwardly into driving engagement with the tubing 62 below the coupling 70 and the tubing slips 20 may be displaced to their open position and the hydraulic motors 58 may be operated in order to drive the chains 50 and remove the tubing from the well bore.

Reference is now made to FIGS. 7 to 13 of the drawings, in which reference numeral 200 refers generally to another pipe injector assembly in accordance with embodiments of this document and, unless otherwise indicated, the same reference numerals used above are used to designate similar parts.

In some embodiments pipe injector 14 includes at least three tubing drive units 36 radially arranged, for example equiangularly (shown in FIG. 12), around a feed axis (shown as axis 18 in FIG. 1). The use of three or more tubing drive units is advantageous because it prevents or reduces undesired bending or arc-ing of the tubing 62 passed through.

In the embodiment, shown, instead of or in addition to making use of the jacking arrangement 16, the assembly includes at least two injectors, for example an upper injector 202 that may be pipe injector 14, and a second pipe injector 204, which is positioned below and in register with the upper injector along the feed axis 18. The structure of the upper and lower injectors 202, 204 may be substantially identical to the injector 14, and for the sake of brevity, is not described in any detail. It should, however, be noted that, in the embodiment shown, the injector 204 may be inverted, however, it need not be.

Further, it is important to note, that the drive components of drive units 36 of the upper injector 202 may be displaceable radially between their closed and open conditions, independently of the drive components of drive units 36 of the lower injector 204 and vice versa.

A method of introducing tubing 62 into or removing it from well bore 30 comprises displacing tubing into or out of a well bore by pipe injector 14, as shown in FIG. 7. In use, as illustrated in FIG. 7 of the drawings, when feeding tubing into the well bore, the drive units 36 of both the upper and lower injectors 202, 204 may be in their closed conditions such that their chains 50 drivingly engage and feed the tubing 62 into the well bore. Referring to FIG. 8, at least some of the drive components of the tubing drive units 36 are displaced outwardly to permit a coupling 70 in the tubing 62 to pass between the drive components. As illustrated, when the drive components of the upper injector 202 are displaced outwardly, the lower injector 204 may displace the tubing 62 longitudinally to permit coupling 70 in the tubing to pass the upper injector 202. This may be initiated with sensor 68. When the sensor 68 senses the presence of a coupling 70 immediately adjacent the upper end of the upper injector 202, the drive units 36 of the upper injector 202 may be displaced to their open condition (shown in FIG. 8) by the associated openers 72 whilst the lower injector 204 continues to feed the tubing into the well. The spacing between the drive units 36 of the upper injector 202 is such that the coupling 70 passes, with clearance, therebetween. Referring to FIG. 9, once the coupling 70 has passed the drive units of the pipe injector, the drive components may be displaced inwardly to drivingly engage the tubing 62. When the drive components of the lower pipe injector 204 are displaced outwardly, the tubing 62 may be longitudinally displaced using the upper pipe injector 202 to permit coupling 70 in the tubing 62 to pass the lower pipe injector 204. Again, this may be done with sensors. Sensors may sense the presence of a coupling clearing either injector in use, in order to move the respective injector back into the closed position. When a second sensor (not shown), positioned between the upper and lower injectors 202, 204 senses the presence of the coupling 70 which is indicative of the fact that the coupling has passed the upper injector 202, the drive units 36 of the upper injector 202 may be displaced to their closed positions in which they drivingly engage the tubing above the coupling 70. The drive units 36 of the lower injector 204 may be then displaced to their open condition (shown in FIG. 10 of the drawings) by the associated openers 72 and the upper injector 202 feeds the tubing into the well bore. When the coupling 70 has passed the lower injector 204 its drive units 36 may be once again returned to their closed condition (shown in FIG. 11) and the tubing may be fed into the well by means of both the upper and lower injectors 202, 204.

It will be appreciated that the pipe injector assembly 200 can also be used to remove tubing from the well bore by following the reverse procedure described above. To this end, suitable sensors will be provided in order to sense the presence of a coupling below the lower injector 204 and between the injectors 202, 204.

The Inventor believes that the embodiments of this document will facilitate the injection of tubing into and removal of tubing from a well bore in an efficient and automated fashion thereby leading to improved productivity.

In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite article “a” before a claim feature does not exclude more than one of the feature being present. Each one of the individual features described here may be used in one or more embodiments and is not, by virtue only of being described here, to be construed as essential to all embodiments as defined by the claims.

Claims

1. A pipe injector assembly, comprising:

a pipe injector that includes at least three tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are laterally displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the lateral spacing between the drive components is increased to permit the passage of a coupling of the tubing.

2. The pipe injector assembly of claim 1 in which the tubing drive units comprise endless chain tubing drive units.

3. The pipe injector assembly of claim 2 in which the drive components associated with each endless chain tubing drive unit comprise:

a chain guide;

an endless feed chain supported on the chain guide and configured in the closed condition to drivingly engage said tubing; and

a chain drive arrangement.

4. The pipe injector assembly of claim 1 in which the tubing drive units are arranged equiangularly around the feed axis.

5. The pipe injector assembly of claim 1 in which the pipe injector is displaceable longitudinally relative to the feed axis when in the open condition.

6. The pipe injector assembly of claim 1 in which the pipe injector is displaceable longitudinally relative to a set of tubing slips that are displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the spacing between the tubing slips is increased to permit the passage of the coupling.

7. The pipe injector assembly of claim 1 further comprising a second injector positioned below and in register with the pipe injector along the feed axis.

8. The pipe injector assembly of claim 7 in which the second pipe injector comprises at least two tubing drive units radially arranged around the feed axis, the tubing drive units of the second pipe injector including drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of the coupling;

in which the tubing drive units of the pipe injector are displaceable from the closed condition to the open condition independently of the tubing drive units of the second pipe injector.

9. The pipe injector assembly of claim 8 in which the second pipe injector comprises at least three tubing drive units radially arranged around the feed axis.

10. The pipe injector assembly of claim 8 in which the tubing drive units of the second pipe injector comprise endless chain tubing drive units.

11. The pipe injector assembly of claim 1 further comprising a sensor configured to sense the presence of a coupling connecting.

12. A method of introducing tubing into or removing it from a well bore, the method comprising:

displacing tubing into or out of a well bore by a pipe injector having at least three tubing drive units radially arranged around the tubing, the tubing drive units having drive components which drivingly engage the tubing;

displacing at least some of the drive components of the tubing drive units outwardly to permit a coupling in the tubing to pass between the drive components; and

once the coupling has passed the drive units, displacing the drive components inwardly to drivingly engage the tubing.

13. The method of claim 12 further comprising:

when the drive components of the pipe injector are displaced outwardly, displacing the pipe injector longitudinally in a direction opposite to a feed direction of the tubing; and

once the drive components have passed the coupling, displacing the drive components inwardly to drivingly engage the tubing.

14. The method of claim 12 in which a second pipe injector is positioned below and in register with the pipe injector along the feed axis, the second pipe injector having at least two tubing drive units including drive components that drivingly engage the tubing, the drive components being radially arranged around the tubing, the method further comprising:

1displacing drive components of the pipe injector outwardly and displacing the tubing longitudinally using the second pipe injector to permit a coupling in the tubing to pass the pipe injector; and

displacing drive components of the second pipe injector outwardly and displacing the tubing longitudinally using the pipe injector to permit a coupling in the tubing to pass the second pipe injector.

15. A pipe injector assembly, comprising:

a pipe injector that includes at least two tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of a coupling of the tubing; and

a set of tubing slips that are laterally displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the lateral spacing between the tubing slips is increased to permit the passage of the coupling;

in which the pipe injector is displaceable longitudinally relative to the set of tubing slips.

16. The pipe injector assembly of claim 15 further comprising a jacking arrangement between the set of tubing slips and the pipe injector.

17. The pipe injector assembly of claim 16 in which the jacking arrangement comprises a hydraulic piston and cylinder arrangement.

18. A method of introducing tubing into or removing it from a well bore, the method comprising:

providing a set of tubing slips and a pipe injector having at least two tubing drive units radially arranged around the tubing, the tubing drive units having drive components which drivingly engage the tubing;

displacing the set of tubing slips outwardly and displacing the tubing longitudinally using the pipe injector to permit a coupling in the tubing to pass the set of tubing slips; and

displacing the drive components outwardly and gripping the tubing longitudinally using the set of tubing slips to longitudinally displace the drive components relative to the set of tubing slips to permit a coupling in the tubing to pass the drive components.

19. The method of claim 18 in which gripping further comprises gripping the tubing using the set of tubing slips and longitudinally displacing the drive components relative to the set of tubing slips using a jacking arrangement between the tubing drive units and the set of tubing slips.

20. The method of claim 18 in which the drive components are displaced longitudinally relative to a tubing feed direction.