Abstract
A device is for directing a fluid flow in an annulus around a pipe string in a horizontal or deviated well. The device has an orientation sensing member adapted to distinguish between the high-side and the low-side of the borehole along the well path. A fluid direction member is adapted to impede the fluid flow in one portion of the annulus so as to at the same time increase the fluid flow in another portion of the annulus; and an activation member for activating the fluid direction member in the well.
Claims
1. A device for directing a fluid flow in an annulus around a pipe string in a horizontal or deviated well having a borehole defining a well path, the device comprising: an orientation sensing member adapted to distinguish between a high-side and a low-side of the borehole along the well path; a fluid direction member adapted to impede the fluid flow in one portion of the annulus so as to at the same time increase the fluid flow in another portion of the annulus; and said one portion being one of the low side and high side of the borehole and said another portion being a different one of the low side and high side; wherein the orientation sensing member is a buoyancy member adapted to self-orient the fluid direction member via buoyancy.
2. The device according to claim 1, wherein the device further comprises an orientation member for orienting the fluid direction member in the borehole.
3. The device according to claim 1, wherein the fluid direction member is adapted to impede the fluid flow on the high-side of the borehole so as to increase the fluid flow on the low-side of the borehole.
4. The device according to claim 1, wherein the fluid direction member is adapted to impede the fluid flow on the low-side of the borehole so as to increase the fluid flow on the high-side of the borehole.
5. The device according to claim 1, wherein the orientation sensing member is a weight member adapted to self-orient the fluid direction member via gravity.
6. The device according to claim 1, wherein the fluid direction member is an expandable packer or sleeve having a non-uniform radius.
7. The device according to claim 1, further comprising an activation member for activating the fluid direction member in the well.
8. The device according to claim 7, wherein the activation member is operateable via one of the following sources: hydraulic pressure in the pipe string; hydraulic pressure in the annulus; chemical reaction; a downhole electric motor; a biasing member; hydrostatic force; a container of compressed fluid; or shape memory metals.
9. A pipe string comprising: a device for directing a fluid flow in an annulus around a pipe string in a horizontal or deviated well having a borehole defining a well path, the device comprising: an orientation sensing member adapted to distinguish between a high-side and a low-side of the borehole along the well path; a fluid direction member adapted to impede the fluid flow in a first one of the high-side and low-side of the borehole so as to at the same time increase the fluid flow in a second one of the high-side and low-side of the borehole; and said one portion being one of the low side and high side of the borehole and said another portion being a different one of the low side and high side; wherein the orientation sensing member is a buoyancy member adapted to self-orient the fluid direction member via buoyancy.
10. The pipe string according to claim 9, wherein the pipe string is a drill string or work string.
11. The pipe string according to claim 9, wherein the pipe string is a casing string or liner.
12. The pipe string according to claim 9, further comprising an activation member for activating the fluid direction member in the well.
13. A method for directing a fluid flow in a horizontal or deviated well via a device for directing a fluid flow in an annulus around a pipe string in a horizontal or deviated well having a borehole defining a well path, the device comprising: an orientation sensing member adapted to distinguish between a high-side and a low-side of the borehole along the well path; a fluid direction member adapted to impede the fluid flow in one portion of the annulus so as to at the same time increase the fluid flow in another portion of the annulus; said one portion being one of the low side and the high side of the borehole and said another portion being a different one of the low side and high side; and wherein the orientation sensing member is a buoyancy member adapted to self-orient the fluid direction member via buoyancy; wherein the method comprises: running the device into the well on a pipe string.
14. The method according to claim 13, wherein the device further comprises an activation member for activating the fluid direction member in the well, and wherein the method further comprises activating the fluid direction member via the activation member when the device has reached a desired depth in the well.
15. The method according to claim 14, wherein the device is run into the well on a drill string or on a work string, and wherein the method further comprises the step of: cleaning at least a portion of the annulus by flowing a cleaning fluid past the activated fluid direction member.
16. The method according to claim 14, wherein the device is run into the well on a casing string, and wherein the method further comprises: cementing at least of portion of the annulus by flowing cement past the activated fluid direction member.
17. The method according to claim 14, wherein the device is run into the well as part of a bottom hole assembly, and wherein the method further comprises: gravel packing at least a portion of the annulus by flowing a slurry past the activated flow direction member.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In the following are described examples of preferred embodiments illustrated in the accompanying drawings, wherein:
(2) FIGS. 1a-c shows a first embodiment of a device according to the present invention;
(3) FIG. 2a-c shows a second embodiment of a device according to the present invention;
(4) FIG. 3 shows a third embodiment of a device according to the present invention;
(5) FIG. 4 shows a fourth embodiment of a device according to the present invention in a non-activated position;
(6) FIG. 5 shows the device from FIG. 4 in an activated position;
(7) FIG. 6 shows, schematically how activation of a device according to the first aspect of the invention may be initiated; and
(8) FIG. 7 shows a pipe string with a plurality of alternative flow diverter devices.
(9) FIG. 8 shows a fifth embodiment of a device according to the present invention; and
(10) FIG. 9 shows the device according to FIG. 8 included into a pipe string according to the second aspect of the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
(11) In the following, the reference numeral 1 will be used to indicate a device according to the first aspect of the invention, whereas the reference numeral 10 will be used to indicate a pipe string comprising a device 1 according to the first aspect of the invention. Identical reference numerals refer to identical or similar features in the drawings. It should also be noted that the drawings are shown schematically and simplified and that the various features in the drawings are not necessarily drawn to scale. In the following the device 1 according to the invention will be referred to as a flow diverter.
(12) FIGS. 1a, b and c show a first embodiment of a flow diverter 1 in a perspective view and in longitudinal and axial cross-sections, respectively. The flow diverter 1 is shown provided on a pipe string 10, wherein only a short portion of the pipe string 10 is shown in the figures for simplicity. The flow diverter 1 is attached to a not shown bearing in order to enable independent rotation of the pipe string 10 relative to the flow diverter 1. The flow diverter 1 is shown comprising a steel base 2 encircling the pipe string 10, and a fluid direction member 4 in the form of a swellable elastomer packer. The swellable elastomer packer 4 covers about half, i.e. a sector of 180, of the circumference of the pipe string 10 extending radially into a not shown annulus. The steel base 2 is further formed with a weight member 6, in the form of a radial protrusion, ensuring that the flow diverter 1 will self-orient itself due to gravity. The radial protrusion 6 will tend to end up at the low-side of the not shown borehole, further implying that the swellable packer 4, in its activated/extended/swelled position, will impeded the flow of fluids on the high-side of the borehole so as to improve the flow on the low-side, in the area between the elastomer packer 4 and the weight member protrusion 6, of the borehole in order to avoid or significantly reduce the problem of cuttings beds described herein. The steel base 2 with the protrusion 6 thus acts both as an orientation sensing member and as an orientation member. In a more sophisticated embodiment, the orientation sensing member may be a gyroscope, a mercury switch or similar, while the orientation member may be a downhole electrical motor. This first embodiment constitutes a simple and low-cost implementation of the invention. It may be particularly useful in use when there is no need to de-activate the fluid direction member 4, such as for cleaning and/or cementing an annulus outside a casing string or liner. A person skilled in the art will understand that the swellable elastomer packer 4 acts as its own activation member, in that it is activated in contact with a certain fluid, typically water or oil.
(13) FIGS. 2a, b and c show a second embodiment of a flow diverter 1 in a perspective view and in longitudinal and axial cross-sections, respectively. The flow diverter differs from the one shown in FIGS. 1a-c in that the steel base 2 is formed with three different protrusions 6, acting as weight members for self-orienting the flow diverter 1, similarly to what was described for the first embodiment above, which may be beneficial for providing more weight for self-orienting the fluid direction member 4.
(14) FIGS. 3a, b and c show a third embodiment of a flow diverter 1 according to the present invention. In the shown embodiment a plurality of smaller buttons/lugs 8 are evenly distributed around the circumference of the pipe 10. The idea is that the flow diverter 1 is wrapped with an elastomer packing element 5. The series of buttons 8 are spaced around the circumference of the pipe string 10. Once the flow diverter 1 is in place in the wellbore, the flow diverter can identify high side, as explained above. It then decides which buttons to activate. In the shown embodiment, there are 12 buttons. The flow diverter would select 4-6 buttons that were most closely aligned with high side. These buttons 8 will then be extended and thereby deform the elastomer packing element 5 on the high-side of the wellbore and force it to contact the wellbore. There may be several rows of buttons of lugs 8 spaced along the length of the pipe string 10 to deform the elastomer packing element 5 over a longer length.
(15) FIGS. 4 and 5 show a fourth embodiment of a flow diverter 1 according to the present invention. In the fourth embodiment, a first portion 12 of the flow diverter 1 is moved axially relative to a second portion 14 of the flow diverter 1, whereby a activation member in form of a cone 16 acts a wedge to force a sheath 18 radially out from the pipe string 10 and into the not shown annulus around the pipe string 10 in order to impede the fluid flow in a portion of the annulus. In the shown embodiment, the sheath 18 covers about one fourth, i.e. 90 segment, of the circumference/annulus around the pipe. The relative, axial motion of the two parts 12, 14 of the flow diverter may be initiated by a downhole actuator 28, as shown schematically in FIG. 6. As such, the fourth embodiment may be suitable for operations where de-activation of the flow direction member may be desirable. In the shown embodiment, the cone 16 and 18 comprises different segments that are separately activatable, depending on the sensed orientation of the device 1 in the wellbore as described herein.
(16) FIG. 6 shows simplified and schematically how activation and de-activation of the sheath and cone embodiment according to FIGS. 4 and 5 may be initiated. A sensor switch 20 receives a signal, by any means described herein, to activate the flow diverter 1 as shown in FIGS. 4 and 5. An operation switch 22 is then activated so as to close an electro-circuit 24 in which a pair of batteries 26 is provided as a power source. The batteries 26 activate a hydraulic actuator 28, hydraulic fluid flowing from the actuator 28 through a valve 30 to a piston 32. The hydraulic force extends a piston rod 34 into contact with the cone 16, forcing the cone 16 in under the sheath 18 to force the sheath 18 radially out from the pipe string as described above. Once the sheath 18 has reached the desired position, the valve 30 may be closed to maintain its activated position. The sheath 18 may subsequently be de-activated/retracted by opening the valve 30 and reversing the activation process.
(17) FIG. 7 shows a pipe string 10 provided with a plurality of simplified flow diverter devices 3, not provided with any orientation sensing members or orientation members. The simplified flow diverters 3 are distributed axially and circumferentially along the pipe string 10 so as to create an even, spiralling fluid flow along axial direction of the pipe string 10 once activated. Due to the distribution of multiple flow diverters 3 along the pipe string 10, there is no need to sense the orientation or to orient the flow diverters, as the pipe string and flow diverters will always be in the right orientation. Activation and optional de-activation of the flow diverters 3 may be initiated as for the flow diverters 1 described herein.
(18) FIG. 8 shows, schematically and simplified, a fifth embodiment of a flow diverter 1 according to the first aspect of the invention. The flow diverter is provided with an orientation sensing member in the form of a buoyancy member 36. In the simplest form the buoyancy member 36 is a pocket filled with a gas such as air or any other fluid with a sufficiently low specific gravity for the buoyancy member 36 to float up to an upper portion of a not shown annulus. The buoyancy member 36 is included into a sleeve 38, where an upper portion of the sleeve containing the buoyancy member 36 acts as a fluid direction member 4 by protruding into the high-side of the not shown annulus.
(19) FIG. 9 shows the embodiment from FIG. 8 as included into a pipe string 10 in an exploded view. The sleeve 38 is rotatably supported on a low-frictional surface 44 of the pipe string 10, while further being connected to two centralizers 42 via axial bearings 40, implying that the sleeve 38 with the buoyancy member 36 may rotate around the pipe string 10 independently of the centralizers 42. It may be useful to use centralizers 42 in combination with the other flow diverters 1 discussed herein in order to provide an improved stand-off between the pipe string 10 and the wall of the borehole.
(20) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article a or an preceding an element does not exclude the presence of a plurality of such elements.
(21) The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
