Mobile coiled tubing drilling apparatus

Abstract

A mobile, coiled tubing drilling apparatus includes a non-rotating mast on a mobile platform. The mast has mounted thereon an injector, a coiled tubing reel having a tubing pay-off point associated therewith, and a tubing control system. The tubing control system is located between the reel and the injector, and includes a tubing abutment adjacent the tubing pay-off point for applying an opposite bend to the tubing during pay-out of the tubing. The reel is mounted for horizontal (x,y) movement such that, during pay-out of the tubing, the tubing pay-off point can be maintained generally above the injector, and can also be moved towards or away from the tubing abutment.

Claims

1. A mobile, coiled tubing drilling apparatus, the apparatus comprising: a non-rotating mast on a mobile platform, the mast having mounted thereon an injector, a coiled tubing reel having a tubing pay-off point associated therewith, and a tubing control system, wherein: the tubing control system is between the reel and the injector, and includes a tubing abutment adjacent the tubing pay-off point for applying an opposite bend to the tubing during pay-out of the tubing; and the reel is mounted for horizontal (x,y) movement such that, during pay-out of the tubing, the tubing pay-off point can be maintained generally above the injector, and can also be moved towards or away from the tubing abutment.

2. The apparatus according to claim 1, wherein the injector includes an operational axis and the reel is mounted for horizontal (x,y) movement such that, during pay-out of the tubing, the tubing pay-off point can be maintained generally above the injector but away from the injector's operational axis.

3. The apparatus according to claim 2, wherein the reel is mounted for horizontal (x,y) movement such that, during take-up of the tubing, the tubing take-on point can be maintained directly above the injector at a point along the injector's operational axis.

4. The apparatus according to claim 1, wherein the tubing control system also includes an adjustable tubing straightener after the tubing abutment and before the injector.

5. The apparatus according to claim 1, wherein the tubing abutment is fixed with respect to the mast.

6. The apparatus according to claim 1, wherein the tubing abutment is an elongate abutment beam, fixed generally vertically to the mast with an upper end and a lower end, and with the upper end being the end located adjacent the tubing pay-off point of the reel during pay-out.

7. The apparatus according to claim 6, wherein the elongate abutment beam is a substantially straight and elongate abutment beam, having a channel therealong that is capable of receiving and guiding therealong tubing from the reel.

8. The apparatus according to claim 1, wherein the mast is mounted on the mobile platform so as to be movable between an upright drilling position where the reel is above the injector, and a lowered transport position.

9. The apparatus according to claim 1, wherein the reel is also mounted on the mast for vertical (z) movement.

10. A method of operating a mobile, coiled tubing drilling apparatus, the apparatus including a non-rotating mast on a mobile platform, the mast having mounted thereon an injector, a coiled tubing reel having a tubing pay-off point associated therewith, and a tubing control system between the reel and the injector, wherein the reel is mounted for horizontal (x,y) movement and the tubing control system includes a tubing abutment adjacent the tubing pay-off point, the method including: maintaining the tubing pay-off point generally above the injector and adjacent to the tubing abutment during pay-out of the tubing by way of the horizontal (x,y) movement of the reel; applying an opposite bend to the tubing during pay-out of the tubing by engagement of the tubing adjacent the pay-off point with the tubing abutment; and maintaining a tubing take-on point above the injector and away from the tubing abutment during take-up of the tubing by way of the horizontal (x,y) movement of the reel.

11. The method according to claim 10, wherein the injector includes an operational axis and the reel is mounted for horizontal (x,y) movement such that, during pay-out of the tubing, the tubing pay-off point can be maintained generally above the injector but away from the injector's operational axis.

12. The method according to claim 11, wherein the reel is mounted for horizontal (x,y) movement such that, during take-up of the tubing, the tubing take-on point can be maintained directly above the injector at a point along the injector's operational axis.

13. The method according to claim 10, wherein the tubing abutment is fixed with respect to the mast.

14. The method according to claim 10, wherein the tubing control system also includes an adjustable tubing straightener after the tubing abutment and before the injector.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Having briefly described the general concepts involved with the present invention, a preferred embodiment of a mobile coiled tubing drilling apparatus will now be described that is in accordance with the present invention. However, it is to be understood that the following description is not to limit the generality of the above description.

(2) In the drawings:

(3) FIG. 1 is a perspective view from above of a mobile, coiled tubing drilling apparatus in accordance with a preferred embodiment of the present invention, deployed in its drilling position;

(4) FIG. 2 is a side view of the apparatus of FIG. 1 in a transport position;

(5) FIGS. 3(a) and 3(b) are schematic side views of the mast and reel of the apparatus of FIG. 1 when in tubing pay-out mode (FIG. 3(a)) and tubing take-up mode (FIG. 3(b)); and

(6) FIGS. 4(a) and 4(b) are schematic top views of a preferred reel mounting configuration for use with the apparatus of FIG. 1 when in tubing pay-out mode (FIG. 3(a)).

DETAILED DESCRIPTION

(7) Illustrated in FIG. 1 is a mobile, coiled tubing drilling apparatus 10 in its upright drilling position, while FIG. 2 shows the same apparatus 10 in its lowered transport position. The apparatus 10 generally includes a mast 12 mounted on a mobile platform 14 in a manner such that the mast is not rotatable about a vertical axis when in its upright drilling position. The apparatus also includes a coiled tubing reel 16, an injector 18 (with injector guide rollers 19) and a tubing control system in the form of an elongate tubing abutment 20. As will be better understood from the following description, point A in FIG. 1 is a point on the reel and is the general location of both a tubing pay-off point and a tubing take-up point (referred to later as A′).

(8) The vertical axis mentioned above is designated in FIG. 1 as the z axis in the identified x-y-z coordinate system, with the x axis (or x direction) being the direction of movement for the tubing pay-off point A (and thus also the reel 16) towards and away from the tubing abutment 20. The y axis (or y direction) is then the direction of movement for the tubing pay-off point A (and again also the reel 16) along the longitudinal axis of the reel 16.

(9) The mobility of the platform 14 is provided in this embodiment by a continuous track propulsion system 15, while much of the ancillary drilling equipment provided on the mobile platform (such as fluid pumps, air compressors, nitrogen purge systems, a diesel engine, hydraulic pumps and valves, and suitable control and operating systems) have been omitted from FIG. 1 and FIG. 2 for ease of illustration. Additionally, in this embodiment, the reel 16 is mounted on the mast 12 for vertical (z) movement by way of the mast 12 having a telescoping configuration (not shown).

(10) As mentioned above, such vertical movement of the reel 16 is advantageous in providing for relatively small vertical movement of a drill bit (for example), located at the bottom of the tubing in a borehole, into and out of contact with the bottom of the borehole. This is in preference to such movement having to be provided by rotating the reel 16 to raise or lower the drill bit, which, if avoided, can further reduce the stresses placed on the tubing, further increasing the operating life of the tubing.

(11) The mast 12 of the apparatus 10 also includes, below the injector 18, a retractable, conventional rotary head 22 (only partly shown) that can be used for drilling with conventional drill rods. In this respect, the apparatus 10 can then be used to install casing or the like to the borehole, or to connect and disconnect the different elements of a bottomhole assembly.

(12) Referring now to FIGS. 3a and 3b, the reel 16 can be seen mounted for horizontal (x,y) movement, with the x direction being left-right across the page and the y direction being into and out of the page, such that, during pay-out of the tubing 30, the tubing pay-off point A can be maintained generally above the injector 18 but away from the injector's operational axis, the operational axis being defined by the pathway through the injector 18 of the longitudinal axis of the tubing 30 therein.

(13) In this embodiment, the tubing control system of the apparatus 10 also includes an adjustable tubing straightener 32 after the tubing abutment 20 and before the injector 18, the tubing straightener 32 being adjustable such that it can engage tubing 30 entering or exiting the injector 18 and be utilised to provide more or less (or no) force to tubing 30 entering or exiting the injector 18. In this embodiment, the adjustable tubing straightener 32 is shown in FIG. 3(a) as being in engagement with the tubing 30 entering the injector 18 (during pay-out), but in FIG. 3(b) is shown not engaging with the tubing 30 exiting the injector 18 (during take-up), for reasons that will be outlined below. The adjustable straightener 32 is a single hydraulic powered roller configured to engage with tubing against a fixed abutment.

(14) The tubing abutment 20 is shown fixed with respect to the mast 12 so that the movement of the reel 16 to maintain the tubing 30 pay-off point A generally above the injector 18 during pay-out of the tubing 30 also positions the tubing pay-off point A adjacent the tubing abutment 20 so that the tubing 30 engages with the tubing abutment 20. As mentioned above, this engagement with the tubing abutment 20 places an opposite bend in the tubing 30 during pay-out (such a bend being “opposite” to the bend in the tubing 30 that already exists in the coiled tubing from it being coiled on the reel 16), which in this embodiment occurs before the tubing 30 passes through the adjustable tubing straightener 32 and the injector 18.

(15) The tubing abutment 20 is an elongate abutment beam, fixed generally vertically to the mast 12 with an upper end 20a and a lower end 20b, and with the upper end 20a being the end located above the tubing pay-off point A of the reel 16 during operation. The uncoiling tubing 30 engages with the abutment beam and is guided along the abutment beam to the adjustable straightener 32 and then to the injector 18 during pay-out of the tubing 30. The elongate abutment beam is substantially straight and elongate, and has a channel 36 therealong that is capable of receiving and guiding therealong tubing 30 from the reel 16.

(16) As mentioned above, the application of this opposite bend to the tubing 30 at a location closely adjacent to the tubing pay-off point A has been found to minimise stress on the tubing 30 (and thus increase the operational life of the tubing 30) while reasonably accurately aligning the tubing 30 with the adjustable tubing straightener 32 and the injector 18. The application of the opposite bend has also been found to reduce any residual plastic bend remaining in the tubing 30 before entering the borehole, assisting in avoiding subsequent difficulties with the control and direction of the borehole.

(17) In contrast, and referring to FIG. 3b which shows the re-coiling of the tubing 30 when the tubing 30 is being withdrawn from the borehole (not shown), the tubing 30 entering the injector 18 from below has of course already been straightened, and thus is not subjected to the same existing bend that is present with coiled tubing 30 being uncoiled (FIG. 3(a)). In this phase, the tubing abutment 20 is not utilised by the apparatus 10 during tubing take-up, and a tubing take-on point A′ (being essentially the same point during re-coiling as the tubing pay-off point A during uncoiling) is made as close as operationally possible to a point along the injector's operational axis, and thus will be directly above the injector 18.

(18) With reference to FIGS. 4(a) and 4(b), as mentioned above the reel 16 is mounted on the mast 12 for horizontal (x,y) movement such that the tubing pay-off point A can be maintained generally above the injector 18 during pay-out of the tubing 30 and such that the tubing take-on point A′ can be maintained directly above the injector 18 during take-up of the tubing 30.

(19) In this respect, and identifying movement in the x direction as being movement of the reel towards and away from the mast 12 (left and right on the page), and movement in the y direction as being movement of the reel 16 along its own longitudinal axis (axis Y-Y in FIGS. 4(a) and 4(b)), the x direction movement is provided by mounting the reel 16 on the mast 12 via pivoting arms 40 that are controlled to pivot towards and away from the mast 12.

(20) Such pivoting movement therefore moves the entire reel 16 towards and away from the mast 12 (as required, either before, during or after drilling) and thus towards and away from the tubing abutment 20. Mounting the reel 16 in this manner provides for movement of the longitudinal axis Y-Y of the reel 16 towards and away from the tubing abutment 20, and of the coiled tubing 30a, 30b on the reel 16 towards and away from the tubing abutment 20, and thus of the pay-off point A of the tubing towards and away from the tubing abutment 20.

(21) Indeed, during drilling, this movement permits the tubing 30a, 30b at the pay-off point A to be continually urged towards and against the tubing abutment 20 as the tubing 30a, 30b uncoils from the reel 16 and as the diameter of the tubing 30a, 30b coiled on the reel 16 decreases, as is shown from FIG. 4(a) where the reel 16 is full of tubing 30a through to FIG. 4(b) where the tubing 30b is almost entirely unwound from the reel 16.

(22) In this respect, it will be appreciated that the pay-off point A of the tubing 30a, 30b will move along the longitudinal axis Y-Y of the reel 16 as the reel rotates about its longitudinal axis Y-Y and as the tubing 30a, 30b uncoils. With the reel 16 being adapted to provide for continual adjustability of the reel 16 along its longitudinal axis Y-Y, the reel can be moved in the y direction in response to the pay-off point A moving in the y-direction, thus keeping the pay-off point A adjacent to the tubing abutment 20 as required, and also keeping the tubing 30a, 30b at that point in engagement with the tubing abutment 20 to apply the requisite opposite bend thereto.

(23) Finally, there may be other variations and modifications made to the configurations described herein that are also within the scope of the present invention.