DOWNHOLE JOINT ROTATOR

Abstract

A downhole tubing rotator that has a housing configured into a production tubing string in a well in a reservoir, the housing being generally cylindrical with a hollow center and containing a two pole, three phase induction squirrel cage motor operatively connected to a tubing rotator configured to clamp onto a production tubing joint and rotate one or more production tubing joints (but not an entire production tubing string) when the motor is activated. An armor-protected insulated power and control cable connects the motor to a control box positioned at a surface of a reservoir and various sensors provide feedback for the unit. Methods of using this tool are also provided.

Claims

1. A downhole joint rotator tool, said tool comprising: a) a housing configured to fit into a production tubing string downhole in a well in a reservoir; b) said housing being generally cylindrical with a hollow center; c) said housing having a tool joint at an upper end thereof to connect to a joint above said tool and a swivel joint at a lower end for a swiveling connection to a joint below said tool; d) said housing comprising an induction motor with a hollow center and a rotator that attaches a joint, said motor and rotator configured to rotate said joint; e) an armor-protected insulated power and control cable connecting said induction motor to a control box positioned at a surface of said reservoir; f) wherein said tool is able to rotate joints below said tool, but not above said tool (or vice versa), when said induction motor is activated via said control box.

2. The tool of claim 1, further comprising an anchor module to anchor the tool to a casing in said well.

3. The tool of claim 1, said motor being a two pole, three phase induction squirrel cage motor.

4. The tool of claim 1, further comprising one or more sensors operatively connected to said tool and said cable.

5. The tool of claim 4, further comprising a torque sensor operatively connected to said tubing rotator.

6. The tool of claim 4, further comprising a temperature sensor and a pressure sensor operatively coupled to said cable.

7. The tool of claim 4, further comprising a motor temperature sensor operatively coupled to said cable.

8. The tool of claim 6, further comprising a vibration sensor operatively coupled to said cable.

9. The tool of claim 1, further comprising one or more centralizers on an exterior of said housing.

10. The tool of claim 1, further comprising a plurality of two pole, three phase induction squirrel cage motors each operatively connected to a tubing rotator.

11. A downhole joint rotator tool, said tool comprising: a) a cylindrical housing with a hollow center configured to fit into a production tubing string in a well in a reservoir; b) either said production tubing string or said tool comprising at least one swivel joint; c) said housing comprising an induction motor with a hollow center configured to rotate at least one joint above or below said tool; d) an armor-protected insulated power and control cable connecting said induction motor to a control box positioned at a surface of a reservoir; e) wherein said tool is able to rotate one or more joints above or below said tool but not an entirety of said production tubing string when said induction motor is activated via said control box.

12. The tool of claim 11, further comprising an anchor module to anchor the tool to a casing in said well.

13. The tool of claim 11, said motor being a two pole, three phase induction squirrel cage motor.

14. The tool of claim 11, further comprising one or more sensors operatively connected to said tool and said cable, said sensors selected from a torque sensor operatively connected to said tubing rotator, a temperature sensor and a pressure sensor operatively coupled to said cable, a motor temperature sensor operatively coupled to said cable and a vibration sensor operatively coupled to said cable.

15. A method of rotating one or more production tubing joints in a production tubing string, said method comprising: a) deploying a production tubing string inside a casing in a well in a reservoir, said string comprising a plurality of tubing joints and the tool of claim 1 and a swivel joint, said tool and said swivel joint bracketing a region of tubing to be rotated; b) applying power to said tool such that one or more tubing joints in said region are rotated from an initial position, but not an entirety of said production tubing string; and c) producing hydrocarbon from said production tubing.

16. The method of claim 15, wherein said rotation is <10° per day, <5° per day, or about <2° per day.

17. The method of claim 15, wherein said rotation is intermittent.

18. A method of rotating one or more production tubing joints in a production tubing string, said method comprising: a) deploying a production tubing string inside a casing in a well in a reservoir, said string comprising a plurality of tubing joints and a pair of tools of claim 1 bracketing a region of tubing to be rotated; b) applying power to said tool such that one or more tubing joints in said region are rotated from an initial position, but not an entirety of said production tubing string; and c) producing hydrocarbon from said production tubing.

19. The method of claim 18, wherein said rotation is <10° per day, <5° per day, or about <2° per day.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] FIG. 1. Schematic of the system deployed downhole.

[0078] FIG. 2. Downhole joint rotator tool.

[0079] FIG. 3. Motor.

DETAILED DESCRIPTION

[0080] FIG. 1 shows the well 100 in a reservoir 101 (not drawn to scale). A control panel 104 at the surface 103 is connected via control line 108 to the downhole rotator tool 110. Tool 110 fits into the tubing string 106 and is small enough in outer diameter (OD) to fit inside the production casing 107. The tool 110 comprises a generally cylindrical housing 114 with hollow center that contains tubing rotator 111 driven by motor 112 (here shown as a simple black box for both components). Shown here is a swivel 113 at a lower end of the tubing string, which allows the tool to rotate just the portion above the swivel. A second swivel joint may be located above the tool and below the well deviation or can be in a second tool. Also shown here is pump 116, packer 115 and rod string 105 which provide the artificial lift system.

[0081] The tool can be anchored to the casing or just have some sort of contact with the casing to account for the reactive torque from rotating the tubing. For example, the tool can have either drag blocks that are incorporated into the tool or arms or fins that are electrically deployed to the casing when the rotator is activated. The tool will be made up into the tubing string just as any other tubing string component would be, i.e. packers, subs, nipples, etc. and thus connected thereto via two tool joints or a tool joint and swivel joint.

[0082] The DJR tool is shown in more detail in FIG. 2. DJR tool 200 fits into the tubing 201 inside casing 202 in reservoir 203, typically via standard tool joint fittings (usually threaded ends), not shown herein. The casing 202 is cemented 211 as is typical, but this is not an essential feature. Power and control cable 204 connects to pump control box 205 at surface 206 powered by electric supply 207. Cable 204 can be round, unless space needs may dictate a flat cable. In addition, the cable is armor protected and insulated.

[0083] Tool 200 has a rotator portion 208 that grips the tubing to rotate it driven by motor 209 which is protected from downhole fluids by the motor protector 210. The submersible motor is preferably a two pole, three phase induction motor, but any suitable motor could be used.

[0084] Swivel 211 at the bottom end of the string allows the joints above it to rotate freely. See also swivel 211 at top above several joints. The bottom-most swivel 211 may be part of tool 200 or separate therefrom, as preferred. If part of the tool, it may be exchangeable with a series of swivels whose top end each fits the tool, but having different lower end diameters, each designed to fit on a different size tubing.

[0085] The rotator portion 208 may also come in series, the lower end of each configured to fit the motor and the upper end to fit different size tubing. Alternatively, and preferably, an adaptor portion (not shown) may be provided to accommodate different size tubing. The adaptor lower end would thus always be the same size in order to couple to the rotator 208 and the upper end would have differing diameter tool joints.

[0086] Also seen is anchor module 212 with legs 213 to brace against casing 202, and may also serve a centralizing function. Also seen are sensors and processors 221, 222, and 223.

[0087] A cutaway motor is shown in FIG. 3, wherein cable output 301 is shown, along with stator 303 and O-rings 305. Windings 313 surround magnets 311 mounted on rotor rings and providing the motivating force when electricity is run therethrough. A cooling channel 307 is also shown.

[0088] In one embodiment, there may be a second motor and a second rotator, or a single motor running two rotators, allowing the grabbing of the upper and lower ends of a joint or joints to rotate same. However, this is more costly, and in most cases, one set of DJR and swivel would be suitable in nearly all situations, especially since wells that are on rod pump lift systems are generally lower producers.

[0089] The present invention is exemplified with respect to a downhole tubing rotator comprising a single motor and rotator. However, this is exemplary only, and the invention can be broadly applied to add additional motors and rotators, and add various sensors, centralizers, and the like. Alternatively, two tools may be deployed down hole as needed for more strength or to bracket a region of rotation. The examples are intended to be illustrative only, and not unduly limit the scope of the appended claims.

[0090] The following references are each incorporated by reference in their entireties for all purposes. [0091] SPE-16198-PA (1988) MCaslin, M. K., A Study of the Methods for Preventing Rod-Wear Tubing Leaks in Sucker-Rod Pumping Wells Prod Eng 3(04): 615-618. [0092] U.S. Pat. No. 5,327,975 Tubing anchor catcher with rotating mandrel [0093] U.S. Pat. No. 5,427,178 Tubing rotator and hanger [0094] U.S. Pat. No. 5,431,230 Slant wellbore tubing anchor catcher with rotating mandrel [0095] U.S. Pat. No. 5,566,769 Tubular rotation tool for snubbing operations [0096] U.S. Pat. No. 5,732,777 Well tubing suspension and rotator system [0097] U.S. Pat. No. 6,026,898 Integral tubing head and rotator [0098] U.S. Pat. No. 6,199,630 Pull-through tubing string rotator for an oil well [0099] U.S. Pat. No. 6,543,533 Well tubing rotator [0100] U.S. Pat. No. 6,834,717 Tubing rotator [0101] U.S. Pat. No. 7,306,031 Tubing string rotator and method [0102] U.S. Pat. No. 8,272,434 Tubing string hanger and tensioner assembly [0103] U.S. Pat. No. 9,366,104 Downhole tubing rotators and related