Downhole tool with casing scraper with induced rotation

A downhole tool for cleaning debris from an inner surface of a downhole casing that includes an inner mandrel moveable within the casing; and a scraper mandrel movably coupled to the outside of the inner mandrel by the engagement of a lug within a groove, the scraper mandrel including a scraper blade positioned on an outside of the scraper mandrel. Longitudinal movement of the scraper mandrel relative to the inner mandrel causes the lug to move within the groove, causing the scraper mandrel and the scraper blade to rotate relative to the inner mandrel and clean debris from the inner surface of the casing. The longitudinal movement is achieved by restraining movement of the scraper mandrel relative to the inner mandrel by contacting the debris with a scraper blade on the outside of the scraper mandrel, causing the scraper mandrel to move longitudinally relative to the inner mandrel.

BACKGROUND

This section is intended to provide relevant background information to facilitate a better understanding of the various aspects of the described embodiments. Accordingly, these statements are to be read in this light and not as admissions of prior art.

Many wellbore drilling, completion, and/or production operations in the oil and gas industry require isolation of a particular zone within a wellbore to achieve a desired result. However, multiple trips are often required to isolate the particular zone, to perform the wellbore operation, and to carry on another subsequent wellbore operation effectively. For example, a trip may be required to set the isolation tool in a casing extending within the wellbore at a depth interval so that the particular zone requiring isolation for execution of the wellbore operation is isolated. Another trip may be required to complete the wellbore operation. Yet another trip may be required to remove the isolation tool. Still another trip may be required to carry on another wellbore operation subsequently. Moreover, depending on the characteristics of the wellbore and the casing, one or more additional trips may be necessary to clean the casing at the depth interval before the isolation tool is set at the depth interval to ensure an effective seal between the isolation tool and the casing. It would therefore be desirable to reduce the number of trips required to isolate the particular zone, to perform the wellbore operation, and to carry on another subsequent wellbore operation effectively. Therefore, what is needed is an apparatus, system, and/or method that addresses one or more of the foregoing issues, and/or one or more other issues.

DETAILED DESCRIPTION

The present disclosure describes a downhole tool with a casing scraper usable as part of a system for cleaning debris from an inner surface of a downhole casing. The downhole tool uses an inner mandrel moveable within the casing. A scraper mandrel is moveable on the outside of the inner mandrel by the engagement of a lug moveable within a groove. The scraper mandrel includes a scraper blade positioned on the outside of the scraper mandrel that engages the inner surface of the casing. As the inner mandrel moves within the casing, friction from engagement of the scraper blade with the casing restrains movement of the scraper mandrel relative to the inner mandrel, causing the lug to move within the groove and rotate the scraper blade to clear debris from the inner surface of the casing.

Although a figure may depict a horizontal wellbore or a vertical wellbore, unless indicated otherwise, the various aspects of the present disclosure are equally well suited for use in wellbores having other orientations including vertical wellbores, horizontal wellbores, slanted wellbores, multilateral wellbores, or the like. Unless otherwise noted, even though a figure may depict an offshore operation, the various aspects of the present disclosure are equally well suited for use in onshore operations. Unless otherwise noted, even though a figure may depict a cased-hole wellbore, the various aspects of the present disclosure are equally well suited for use in open-hole wellbore operations.

Referring toFIG.1, an offshore oil and gas platform100is schematically illustrated. The offshore oil and gas platform100includes a semi-submersible platform105that is positioned over a submerged oil and gas formation110located below a sea floor115. A subsea conduit120extends from a deck125of the platform105to a subsea wellhead installation130. One or more pressure control devices135, such as, for example, blowout preventers (BOPs), and/or other equipment associated with drilling or producing a wellbore may be provided at the subsea wellhead installation130or elsewhere in the system. The platform105may include a hoisting apparatus140, a derrick145, a travel block150, a hook155, and a swivel160, which components are together operable for raising and lowering a conveyance string165.

The conveyance string165may be, include, or be part of, for example, a casing, a drill string, a completion string, a work string, a pipe joint, coiled tubing, production tubing, other types of pipe or tubing strings, and/or other types of conveyance vehicles, such as wireline, slickline, and/or the like. For example, the conveyance string165may be an axially extending tubular string made up of a plurality of pipe joints coupled to together end-to-end. The platform105may also include a kelly, a rotary table, a top drive unit, and/or other equipment associated with the rotation and/or translation of the conveyance string165. A wellbore170extends from the subsea wellhead installation130and through the various earth strata, including the formation110. At least a portion of the wellbore170includes a downhole casing175cemented therein. The casing175includes an inner surface176to which debris may adhere over time.

A generally tubular downhole tool180is connected to the conveyance string165and extends within the wellbore170. The downhole tool180includes a setting tool185, an isolation tool190connected to the setting tool185, and a casing scraper195. Although described herein as part of the downhole tool180, the casing scraper195may instead be deployed into the wellbore170as a standalone device for cleanout runs or integrated into a single-trip system in combination with other wellbore cleaning tools. The conveyance string165is adapted to convey the downhole tool180into the wellbore170. In addition, or instead, the downhole tool180may be a “pumpdown” type tool conveyable into the wellbore170by hydraulic pressure inside the casing175and above the downhole tool180. The setting tool185may be, for example, an electric wireline, slickline, coiled tubing, mechanical, or hydraulic setting tool.

The isolation tool190is adapted to provide zonal isolation of the wellbore170so that a wellbore operation in which such isolation is required may be performed. In some embodiments, the isolation tool190is a frac plug used primarily between zones in multistage stimulation treatments, in which case the frac plug is adapted to isolate a lower zone during stimulation but to allow flow from below once the stimulation is over to aid in well cleanup. The isolation tool190may be, for example, a bridge plug that can be used in multistage stimulation treatments to provide isolation between zones or to provide a barrier for temporary abandonment or BOP change out. The isolation tool190may alternatively be a packer such as, for example, a squeeze packer. The isolation tool190may also be any one of Halliburton's EZ DRILL®, FAS DRILL®, and/or OBSIDIAN® plugs and packers.

Referring toFIGS.2A-2F, an embodiment of a downhole tool200in the form of a casing scraper is shown. The downhole tool200may be used, for example as the casing scraper195shown inFIG.1. The downhole tool200is moveable within the downhole casing175and includes an inner mandrel202and a scraper mandrel204that is coupled to and moveable on the outside of the inner mandrel202. The coupling is accomplished by the engagement of one or more lugs206on the inside of the scraper mandrel204moveable within a groove208in the inner mandrel202. Although the lugs206are shown on the scraper mandrel204and the groove208is shown in the inner mandrel202, it should be appreciated that the lugs206may instead be on the inner mandrel202and the groove208be on the scraper mandrel204. Relative linear movement between the inner mandrel202and the scraper mandrel204causes the lugs206to move longitudinally within the groove208. In addition, the groove208is shaped such that movement of the lugs206within the groove208also causes the scraper mandrel204to rotate relative to the inner mandrel202. Alternatively, although shown with just a single scraper mandrel204, the downhole tool200may include multiple scraper mandrels204. Further, the inner mandrel202may include longitudinally separated sets of grooves208, one set for each scraper mandrel204. Some of the sets of grooves208may also be oriented in opposite helical configurations such that longitudinal movement of the scraper mandrels204in the same direction relative to the inner mandrel causes the scraper mandrels to rotate in opposite directions. Although not shown, the downhole tool200may also include stabilizers or centralizers to support the movement of the downhole tool200within the casing.

Movement of the scraper mandrel204longitudinally relative to the inner mandrel202from an initial position acts on a biasing device210located in a space between the inner mandrel202and the scraper mandrel204. As shown, the biasing device is a compression spring and the relative movement compresses the spring. However, other biasing devices, such as a hydraulic- or an electrical-based biasing device may also be used. Relative linear movement between the scraper mandrel204and the inner mandrel202produces a force from the biasing device210acting to return the scraper mandrel204to the initial position. For example, compressing a spring produces a force from the spring acting back on the scraper mandrel204in the downhole direction to return the scraper mandrel204to the initial position. The space between the scraper mandrel204and the inner mandrel202for the biasing device210may also be fluid filled. If desired, the inner mandrel may further include ports212to allow fluid or debris to flow into and out of the space for the biasing device210as the scraper mandrel204moves longitudinally back and forth relative to the inner mandrel202. Allowing fluid to flow in and out of the space also prevents the downhole tool200from becoming hydraulically locked.

The scraper mandrel204further includes at least one scraper blade214positioned on the outside of the scraper mandrel204. As shown, there are six scraper blades214positioned around the scraper mandrel204. However, there can be more or fewer than six depending on the design preferences for the downhole tool200. Each scraper blade214fits within a pocket in the outside of the scraper mandrel204. With the scraper blades214positioned within the pockets, the scraper blades are held in place using a retainer216that connects with the outside of the scraper mandrel204. Even with the retainer216in place, each scraper blade214is allowed to move radially relative to the scraper mandrel204, although such movement is restrained by a flange/lip interaction between the scraper blade214and the scraper mandrel204and potentially also the retainer216. Each scraper blade214is also biased radially outward by a spring218between each scraper blade214and the outside of the scraper mandrel204. Each spring biases a scraper blade214outward but allows the scraper blade214to retract radially inward upon sufficient force against the spring218, thus assisting to maintain contact with the inner surface of the casing, even when there is debris located in the casing or if there is a change in size of the inner surface of the casing.

As shown more clearly inFIGS.2D and2E, in use, the downhole tool200is moved within the casing. As the inner mandrel202moves within the casing, friction from engagement of the scraper blades214with the casing or debris on the inner surface of the casing restrains movement of the scraper mandrel204relative to the inner mandrel202, causing the lugs206to move within the grooves208. With the grooves208being configured in a spiral or helical orientation, linear movement of the scraper mandrel204relative to the inner mandrel202causes the scraper mandrel204and thus the scraper blades214to rotate within the casing. Rotation of the scraper mandrel204and the scraper blades214in this manner acts to clean and remove debris from the entire circumference of the inner surface of the casing.

In addition to causing rotation of the scraper mandrel204, longitudinal movement of the scraper mandrel204from an initial position acts on the biasing device210to produce a force to return the scraper mandrel204to the initial position. For example, compressing a spring produces a force from the spring acting back on the scraper mandrel204to return the scraper mandrel204to the initial position. Thus, as the scraper blades214clean the inner surface of the casing to remove debris, the force acting on the scraper mandrel204by the contact with the debris decreases or ends, allowing the force from the biasing device210to return the scraper mandrel204to the initial position. When returned to the initial position, the scraper mandrel204is ready to encounter additional debris on the inner surface of the casing as the downhole tool200continues to move within the casing.

As shown inFIG.2F, the downhole tool200may include multiple scraper mandrels204mounted either on a single inner mandrel202or a string of inner mandrels202. For each scraper mandrel204, there is a corresponding set of grooves208separated longitudinally along the inner mandrel202. As shown, the sets of grooves208are oriented in opposite configurations such that the longitudinal movement of the scraper mandrels204in the same direction causes at least two scraper mandrels204to rotate in opposite directions.

Referring toFIGS.3A-3C, another embodiment of a downhole tool300in the form of a casing scraper is shown. Components similar to the downhole tool200are given similar reference numbers and include an inner mandrel302and a scraper mandrel304. A lug306travels within a groove308. Scraper blades314are biased radially outward by springs318and held in place using a retainer316. Longitudinal movement of the scraper mandrel304relative to the inner mandrel302when encountering friction or debris activates a biasing device310, which may be a spring as shown, to produce a force to return the scraper mandrel304to an initial position. As components are similar to the downhole tool200, the discussion of the arrangement of the components and alternatives applies to the downhole tool300as well. However, unlike the downhole tool200, in the downhole tool300the groove308is configured as a continuous “J-slot” groove that extends around the circumference of the inner mandrel302. As best shown inFIG.3A, the groove308includes a continuous path with downhole stop positions320and uphole stop positions322spaced around the circumference of the inner mandrel302. Each of the downhole stop positions320and uphole stop positions322include at least a portion of the groove308oriented longitudinally. These longitudinal portions allow the scraper mandrel304to move longitudinally within the portions without rotating. The downhole stop positions320and the uphole stop positions322are arcuately offset from each other, with sloped surfaces324on the wall of the groove308opposite each. As the scraper mandrel304reciprocates back and forth in the uphole and downhole directions, the lug306moves within the channel308and contacts the sloped surfaces324. Continued movement of the lug306longitudinally along a particular sloped surface324then also causes the scraper mandrel304to rotate, which also aligns the lug308with the next downhole stop position320or uphole stop position322. Reciprocal movement of the scraper mandrel304relative to the inner mandrel302thus rotates the scraper mandrel304and the scraper blades314to clean and remove debris from the entire circumference of the inner surface of the casing. Although not shown, the downhole tool300may also include stabilizers or centralizers to support the movement of the downhole tool300within the casing.

In addition to causing rotation of the scraper mandrel304, longitudinal movement of the scraper mandrel304from an initial position acts on the biasing device310to produce a force to return the scraper mandrel304to the initial position. For example, compressing a spring produces a force from the spring acting back on the scraper mandrel304to move the scraper mandrel304in the downhole direction. Thus, as the scraper blades314clean the inner surface of the casing to remove debris, the force acting on the scraper mandrel304by the contact with the debris decreases or ends, allowing the force from the biasing device310to move the scraper mandrel304downhole relative to the inner mandrel302. Doing so moves the lug306to the next downhole stop position320in the groove308, where the scraper mandrel304is ready to encounter additional debris on the inner surface of the casing as the downhole tool300continues to move within the casing.

As with the downhole tool200, the downhole tool300may include multiple scraper mandrels304mounted on either a single inner mandrel302or a string of inner mandrels302. For each scraper mandrel304, there is a corresponding groove308separated longitudinally along the inner mandrel302. The grooves308are oriented in opposite configurations such that the longitudinal movement of the scraper mandrels304in the same direction causes at least two scraper mandrels304to rotate in opposite directions.

Examples of the above embodiments include the following numbered examples:

Example 1 is a downhole tool for cleaning debris from an inner surface of a downhole casing, comprising an inner mandrel moveable within the casing and a scraper mandrel movably coupled to the outside of the inner mandrel by the engagement of a lug within a groove, the scraper mandrel comprising a scraper blade positioned on an outside of the scraper mandrel. Longitudinal movement of the scraper mandrel relative to the inner mandrel causes the lug to move within the groove, causing the scraper mandrel and the scraper blade to rotate relative to the inner mandrel and clean debris from the inner surface of the casing.

Example 2. The downhole tool of Example 1, further comprising more than one groove, each groove comprising a helical configuration.

Example 3. The downhole tool of Example 1, wherein the groove comprises a continuous J-slot.

Example 4. The downhole tool of Example 1, further comprising a biasing device activated to produce a force acting on the scraper mandrel by the longitudinal movement of the scraper mandrel relative to the inner mandrel.

Example 5. The downhole tool of Example 1, further comprising multiple scraper blades sized and positioned to contact the debris and restrain and cause the longitudinal movement of the scraper mandrel relative to the inner mandrel.

Example 6. The downhole tool of Example 5, wherein each scraper blade is biased radially outward by a spring.

Example 7. The downhole tool of Example 1, further comprising multiple scraper mandrels and multiple grooves separated longitudinally.

Example 8. The downhole tool of Example 7, wherein the grooves are oriented in opposite configurations such that longitudinal movement of the scraper mandrels in the same direction causes at least two scraper mandrels to rotate in opposite directions.

Example 9. The downhole tool of Example 1, further comprising ports for fluid and debris flow from longitudinal movement of the scraper mandrel relative to the inner mandrel.

Example 10. A method of cleaning debris from an inner surface of a downhole casing, comprising moving a downhole tool through the casing, the downhole tool comprising a scraper mandrel movably coupled to the outside of an inner mandrel; restraining movement of the scraper mandrel relative to the inner mandrel by contacting the debris with a scraper blade on the outside of the scraper mandrel, causing the scraper mandrel to move longitudinally relative to the inner mandrel; and moving a lug within a groove from the relative longitudinal movement of the scraper mandrel relative to the inner mandrel to cause the scraper mandrel and the scraper blade to rotate relative to the casing and clean debris from the inner surface of the casing.

Example 11. The method of Example 10, wherein the downhole tool comprises more than one groove, each groove comprising a helical configuration.

Example 12. The method of Example 10, wherein the groove comprises a continuous J-slot.

Example 13. The method of Example 10, further comprising activating a biasing device with the relative longitudinal movement to produce a force acting on the scraper mandrel.

Example 14. The method of Example 10, further comprising restraining movement of the scraper mandrel relative to the inner mandrel by contacting the debris with multiple scraper blades on the outside of the scraper mandrel

Example 15. The method of Example 10, further comprising multiple scraper mandrels and multiple grooves separated longitudinally.

Example 16. The method of Example 15, wherein the grooves are oriented in opposite configurations such that longitudinal movement of the scraper mandrels in the same direction causes at least two scraper mandrels to rotate in opposite directions.

Example 17. The method of Example 10, further comprising communicating pressure through ports due to the relative longitudinal movement.

Example 18. A system for cleaning debris from an inner surface of a downhole casing, the system comprising a conveyance string and a downhole tool connected to the conveyance string and comprising: an inner mandrel moveable within the casing; and a scraper mandrel movably coupled to the outside of the inner mandrel by the engagement of a lug within a groove, the scraper mandrel comprising a scraper blade positioned on an outside of the scraper mandrel; wherein longitudinal movement of the scraper mandrel relative to the inner mandrel causes the lug to move within the groove, causing the scraper mandrel and the scraper blade to rotate relative to the inner mandrel and clean debris from the inner surface of the casing

Example 19. The system of Example 18, further comprising more than one groove, each groove comprising a helical configuration.

Example 20. The system of Example 18, wherein the groove comprises a continuous J-slot.

The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.