Cleaning Device

Abstract

A cleaning device for use in subterranean fluid production which includes a tool mandrel and a retaining sleeve surrounding the tool mandrel. One or more C-ring-style support rings are used to support and bias cleaning members, such as scraper blades, into contact with the interior radial surface of a retaining sleeve.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to systems and methods for cleaning the interior of tubular members. In particular aspects, the invention relates to methods and devices for scraping wellbore casing.

2. Description of the Related Art

Wellbore cleaning devices include casing scrapers and brushing devices. These mechanisms are used to remove mud, cement sheath, perforation burrs, rust, scale, paraffin, and other debris from the internal surface of wellbore casing. The casing scraper or brush is typically attached to a drill string for operation. The drill string and cleaning device are then disposed within the casing members to be scraped, and rotated.

Typical casing scrapers include a central scraping body and one or more scraping blades that extend radially outwardly therefrom. Conventional casing scrapers generally fall into one of two categories: rotating and non-rotating. With a rotating scraper, the scraping body and the scraping blades are securely affixed to each other so that both rotate with the drill string. In applications where the drill string is rotated for long periods of time, rotating scrapers can cause serious wear and damage to the interior surface of casing. With a non-rotating scraper, only the scraping body rotates with the drill string. The scraper blades are not affixed to the central scraping body, but are urged radially outwardly from it by compression springs in order to provide a force for removal of debris. An example of this type of arrangement is found in U.S. Pat. No. 7,311,141 issued to Tulloch et al.

SUMMARY OF THE INVENTION

The invention provides methods and devices for cleaning the interior of tubular members, such as casing members. Exemplary non-rotating tubular cleaning devices are described which include a unitary central tool mandrel with a surrounding retainer sleeve which a sleeve body with one or more windows disposed laterally through the body. The exemplary cleaning devices also include one or more cleaning members, such as scraper blades. A working portion of each cleaning member extends from the radial interior of the retainer sleeve through a window and radially outside of the retainer sleeve.

At least one annular support member with an axial separation, i.e., a C-ring, is disposed radially within the retainer sleeve and supports the one or more cleaning members outwardly against the interior radial surface of the retainer sleeve. The C-ring support ring preferably has a shape memory that causes the C-ring cleaning member support ring to bias the cleaning member against the interior radial surface of the retainer sleeve. During operation, if the cleaning member contacts an obstruction in a surrounding wellbore, the support ring can deflect inwardly due to the axial separation.

The construction of scraper devices in accordance with the present invention permit these tools to have improved strength and resistance to axial and torsional forces within the work string within which the scraper device is used. The threaded connection of the tool mandrel to other components in a tool string largely governs the strength of the tool overall.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and further aspects of the invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout the several figures of the drawing and wherein:

FIG. 1 is a side, cross-sectional view of an exemplary scraper device constructed in accordance with the present invention.

FIG. 2 is a view of the retaining sleeve, cleaning members and support ring portions of the scraper device, shown in an “unrolled” fashion.

FIG. 3 is an enlarged side, one-quarter cross-sectional view of the scraper device shown in FIG. 1.

FIG. 4 is an external, isometric view of cleaning members and an exemplary support ring used in the scraper device shown in FIGS. 1-3.

FIG. 5 is an axial cross-sectional view taken along lines 5-5 in FIG. 1 and illustrating radial inward retraction of the support ring.

FIG. 6 is a side, one-quarter cross-sectional view of an alternative embodiment for a scraper device constructed in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-4 illustrate an exemplary wellbore scraper device 10 that is constructed in accordance with the present invention. The scraper device 10 is useful for incorporation into a wellbore work string and disposed within a wellbore, as is known in the art. The scraper device 10 includes a generally cylindrical tool mandrel, generally indicated at 12. The tool mandrel 12 defines a central flowbore 14 along its length. The upper end of the tool mandrel 12 preferably includes a box-type threaded connection 16 so that the scraper device 10 may be secured to other portions of a wellbore work string (not shown). The lower end of the tool mandrel 12 includes a pin-type threaded connection 18.

Preferably, the tool mandrel 12 is made up of an upper sub 19 and a lower sub 20 which are affixed together by a threaded connection 22. The tool mandrel 12 presents an outer radial surface 24 having a number of different diameter portions. There is an upper, enlarged-diameter portion 26, a middle, reduced-diameter portion, generally shown at 28, and a lower, enlarged-diameter portion 30.

A retainer sleeve 32 radially surrounds the tool mandrel 12. As best seen in FIGS. 2 and 3, the retainer sleeve 32 has a generally cylindrically-shaped body 34 and presents a number of windows 36 disposed through the sleeve body 34.

A cleaning member support ring 38 is disposed around the reduced-diameter portion 28 of the tool mandrel 12 and located inside of the retainer sleeve 32. An exemplary support ring 38 is depicted apart from the other components of the scraper device 10 in FIG. 4. The support ring 38 includes a generally annular ring body 40 having an axial separation 42 along its length from end-to-end (see FIG. 4) in the manner of a C-ring. The ring body 40 presents a radially outward surface 44 from which a plurality of cleaning members in the form of scraper blades 46 project. The scraper blades 46 may be components that are separate from the ring body 40 or, alternatively, they may be affixed to or integrally formed with the ring body 40. As best seen in FIG. 3, each of the scraper blades 46 include an enlarged base portion 45 and a working portion 47 that extends radially outwardly from the base portion 45. In this embodiment, a single support ring 38 supports and biases a plurality of scraper blades 46 outwardly.

When the support ring 38 is disposed radially inside of the retainer sleeve 32, the working portions 47 of the scraper blades 46 extend through the windows 36 of the retainer sleeve 32 and extend radially outwardly beyond the retainer sleeve 32, as can be seen in FIGS. 1 and 3. The windows 36 of the retainer sleeve 32 and the scraper blades 46 of the scraper ring 38 are shaped in a complimentary manner to each other. The scraper ring body 40 has a shape memory that causes the ring body 40 to urge the base portions 45 of the scraper blades 46 radially outwardly against the interior surface 48 of the retainer sleeve 32. The ring body 40 preferably loosely surrounds the reduced-diameter portion 28 of the tool mandrel 12 so that it is easily rotatable about the tool mandrel 12 during use.

Referring again to FIG. 1, it can be seen that stabilizers 50, 52, of a type known in the art, are also disposed radially around the tool mandrel 12. The stabilizers 50, 52 function to centralize the scraper device 10 within a surrounding wellbore during operation. The stabilizers 50, 52 are rotatable upon the tool mandrel 12 by virtue of bearings 54 which are disposed between the stabilizers and the mandrel 12. Annular needle-type roller bearings may be used or other suitable bearings, such as full-compliment roller bearings or bushings.

Referring now to FIG. 5, it can be seen that the ring body 40 can be deflected inwardly when one or more of the scraper blades 46 is contacted by an obstruction 56 in a surrounding wellbore. By virtue of the separation 42 in the ring body 40, the outer radial surface 44 of the ring body 40 can be moved inwardly away from the surrounding retainer sleeve 32 as indicated by deflection space 58 in FIG. 5.

FIG. 6 depicts an alternative scraper device 10′ which is also constructed in accordance with the present invention. The scraper device 10′ is constructed in the same manner as the cleaning device 10 except where otherwise indicated. In the exemplary cleaning device 10′ each of the scraper blades 46 is urged against the interior surface 48 of the retainer sleeve 32 by multiple support rings 38a, 38b and 38c, each having a C-ring configuration.

It is noted that brushes, magnets or other cleaning members might be used in place of scraper blades to create a cleaning device in accordance with the present invention. It can be seen that the present invention provides a cleaning device that is useful for cleaning tubular members and wellbores that are often used in subterranean fluid production, such as the production of hydrocarbons.

The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope and the spirit of the invention.

Claims

1. A cleaning device for use in subterranean fluid production comprising:

a tool mandrel;

a retaining sleeve radially surrounding the tool mandrel and radially rotatable about the mandrel, the retainer sleeve having a sleeve body with a window disposed through the sleeve body; and

at least one cleaning member disposed within the window of the retainer sleeve, the cleaning member having a base portion and a working portion; and

a support ring that radially surrounds the tool mandrel, the support ring having an annular ring body with an axial separation thereof, the support ring biasing the cleaning member radially outwardly such that the working portion is urged radially outwardly through the window.

2. The cleaning device of claim 1 wherein the support ring has a shape-memory to help bias the cleaning member outwardly.

3. The cleaning device of claim 1 wherein the base portion of the working member is biased against an interior radial surface of the retainer sleeve.

4. The cleaning device of claim 1 wherein there are multiple support rings and multiple support rings support and bias a single cleaning member.

5. The cleaning device of claim 1 wherein a single support ring supports and biases multiple cleaning members.

6. The cleaning device of claim 1 wherein the cleaning member comprises a scraper blade.

7. The cleaning device of claim 1 further comprising a stabilizer radially surrounding the tool mandrel.

8. The cleaning device of claim 1 wherein the support ring deflects radially inwardly in response to an obstruction in a surrounding wellbore.

9. A cleaning device for use in subterranean fluid production comprising:

a tool mandrel;

a retaining sleeve radially surrounding the tool mandrel and radially rotatable about the mandrel, the retainer sleeve having a sleeve body with a plurality of windows disposed through the sleeve body; and

a plurality of cleaning members, each cleaning member disposed within one of the windows of the retainer sleeve, the cleaning members each having a base portion and a working portion; and

a support ring that radially surrounds the tool mandrel, the support ring having an annular ring body with an axial separation thereof, the support ring biasing at least one of the cleaning members radially outwardly such that the working portion is urged radially outwardly through the window within which it is disposed.

10. The cleaning device of claim 9 wherein the cleaning members comprise scraper blades.

11. The cleaning device of claim 9 wherein the support rings each have shape memory to help bias the cleaning members outwardly.

12. The cleaning device of claim 9 wherein the base portion of each working member is biased against an interior radial surface of the retainer sleeve.

13. The cleaning device of claim 9 wherein a single support ring supports and biases multiple cleaning members.

14. The cleaning device of claim 9 wherein there are multiple support rings and wherein multiple support rings support and bias a single cleaning member.

15. The cleaning device of claim 9 further comprising a stabilizer radially surrounding the tool mandrel.

16. The cleaning device of claim 9 wherein the support ring deflects inwardly in response to an obstruction in a surrounding wellbore.

17. A cleaning device for use in subterranean fluid production comprising:

a tool mandrel;

a retaining sleeve radially surrounding the tool mandrel and radially rotatable about the mandrel, the retainer sleeve having a sleeve body with a window disposed through the sleeve body; and

at least one cleaning member disposed within the window of the retainer sleeve, the cleaning member having a base portion and a working portion;

a support ring that radially surrounds the tool mandrel, the support ring having an annular ring body with an axial separation thereof, the support ring biasing the cleaning member radially outwardly such that the working portion is urged radially outwardly through the window; and

a stabilizer radially surrounding the tool mandrel.

18. The cleaning device of claim 17 wherein each of the at least one cleaning member comprises a scraper blade.

19. The cleaning device of claim 17 wherein a single support ring supports and biases multiple cleaning members.

20. The cleaning device of claim 17 wherein there are multiple support rings and wherein multiple support rings support and bias a single cleaning member.