TECHNICAL FIELD

This invention generally relates to cutting. In particular, to an apparatus and method for cutting a tubular that is part of a pipeline or an oil well or a gas well.

BACKGROUND

In many jurisdictions an oil-well or a gas-well operator has a number of regulatory obligations to meet when a well reaches the end of its production life. In general terms, the well may be abandoned by inserting a plug into the well below the surface in order to prevent fluid communication above the plug. Additionally, branches and dead legs of pipelines often require a similar plugging upon abandonment. The present disclosure may collectively refer to a well and a pipeline as a tubular. The plugging is also accompanied with removal of an above-surface portion of the tubular in order to reclaim the surrounding land at the location of the abandoned tubular.

One known approach for plugging and removing the above-surface portion of the tubular is to excavate the earth surrounding the above-surface portion to gain access to the well or pipeline below the surface. Excavation often requires heavy equipment and/or hydrovac trucks and utility locators to avoid damaging utility lines or other sub- surface infrastructure. Once the excavation is complete, a plug can be inserted into the tubular and the above-surface portion can be cut off and removed. Next, the excavated materials are returned in order to fill in the excavated hole.

A cutting torch can be used to cut the tubular, but the open flame or sparking may pose a safety hazard if volatile hydrocarbons are present.

Another approach for plugging and removing the above-surface portion of the tubular is to insert a plug into the well or pipeline to a predetermined depth below the surface. Once plugged, a high-pressure water cutting tool is inserted into the tubular for cutting the tubular above the plug. Water cutting tools typically require equipment to pressurize the water, clean water source and in some cases, additives such as sand, to be transported to the tubular's location. Access for such tools, water sources and additives to the tubular may be limited by the conditions of the land at the location. Furthermore, water cutting tools may require a heating unit to operate in colder temperatures.

SUMMARY

This invention is based, at least in part, on the development of a more efficient and field repairable cutter tool have at least two cutting elements.

In illustrative embodiments of the present invention, there is provided a cutter tool for cutting a tubular, the cutter tool comprising: a) a housing operable to be inserted into the tubular; b) a shaft operably moveable within the housing, the shaft having an operating end and a guide end; and c) at least two cutting members operably coupled to the guide end of the shaft, the at least two cutting members each having a cutting means for cutting the tubular and each having an engagement means for engaging the guide end of the shaft; wherein the movement of the operating end of the shaft in a first direction causes the at least two cutting members to move from a retracted position to a cutting position and movement of the operating end of the shaft in a second direction causes the at least two cutting members to move from a cutting position to a retracted position.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the movement of the shaft is movement along a longitudinal axis of the housing.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the movement of the shaft is rotation of the shaft relative to the housing.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein further comprising an operating body, which operating body is operably coupled to the operating end of the shaft and is operable to move the operating end of the shaft in the first and second directions. ln illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the operating body is a hydraulic or a pneumatic system.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein further comprising a rotation means for rotating the cutter tool.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the rotation body comprises a motor.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein further comprising a biasing means operable to bias the shaft in the first direction.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein at least one cutting means on the at least two cutting members is a cutting wheel.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein all the cutting means on the at least two \cutting members is a cutting wheel.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the guide end of the shaft is a spear head body that couples with the at least two cutting members.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the at least two cutting members are two cutting members.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the at least two cutting members are four cutting members.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the guide end of the shaft comprises a thread that couples with the at least two cutting members.

In illustrative embodiments of the present invention, there is provided a cutter tool described herein wherein the operating end of the shaft is threaded and the thread on the operating end engages with a threaded portion of the housing.

Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention,

Figure 1 is an illustration of a side view of a cutter tool according to the present invention.

Figure 2 is an illustration of a cross-sectional view of a cutter tool according to the present invention.

Figure 3 is an illustration of a cross-sectional view of a portion of a cutter tool according to the present invention.

Figure 4 is an illustration of a cross-sectional view of a portion of a cutter tool according to the present invention, which shows a portion of a shaft and a portion of a housing.

Figure 5 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows a portion of the shaft.

Figure 6 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows a portion of the shaft.

Figure 7 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows the shaft and its engagement with cutting members.

Figure 8 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows a head and cap portion of the housing.

Figure 9 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows a head and cap portion of the housing. Figure 10 is an illustration of a top view of a portion of a cutter tool according to the present invention, which shows a cutting member.

Figure 11 is an illustration of a side view of a portion of a cutter tool according to the present invention, which shows a cutting member.

DETAILED DESCRIPTION

Technical and scientific terms used herein have the meaning as commonly understood by a person of skill in the art unless defined otherwise or the context makes clear that a different meaning is used.

Embodiments of the present invention relate to cutter tools that can be used to cut tubulars from the inside thereof. Some embodiments of the present invention relate to cutter tools that can be used to cut tubulars of oil wells, gas wells, and other pipelines. The cutter tools of the present invention can be used to cut tubulars of various sizes and various materials in various types of installations. For example, the tubular to be cut may be underground, may be above ground, and/or may have a portion above ground and a portion underground. The tubular may be a single walled tubular or may be a tubular having an inner tubular and an outer tubular which define an annular space therebetween. All of or a portion of the annular space may or may not be filled with a material such as concrete. Tubulars suitable for cutting using a cutter tool of the present invention, include, but are not limited to, plastic tubulars, aluminum tubulars, carbon fiber tubulars, and composite tubulars.

The cutter tools of the present invention have at least two cutting members that can be moved between a retracted and a cutting position while the cutting members are positioned at the locations within the tubular where the cuts will be made. The cutter tools can be rotated by a user or by equipment at the surface and as the cutter tool is being rotated, the position of the cutting member can be adjusted to start, continue, and finish cutting through the tubular. In some embodiments of the present disclosure, the position of the cutting member can be adjusted by a user at surface while the cutter tool is being rotated beneath the ground. Referring to the Figures, in embodiments of the present invention, there is provided a cutter tool for cutting a tubular shown generally at 10. The cutter tool comprises: a) a housing 20 operable to be inserted into the tubular; b) a shaft 30 operably moveable within the housing 20, the shaft 30 having an operating end 40 and a guide end 50; and c) at least two cutting members 60 operably coupled to the guide end 50 of the shaft 30, the at least two cutting members 60 each having a cutting means 70 for cutting the tubular and each having an engagement means 80 for engaging the guide end 50 of the shaft 30.

Movement of the operating end 40 of the shaft 30 in a first direction causes the at least two cutting members 60 to move from a retracted position to a cutting position and movement of the operating end 40 of the shaft 30 in a second direction causes the at least two cutting members 60 to move from a cutting position to a retracted position.

In embodiments of the present invention, the housing 20 may be any material that is suitably strong enough to withstand the forces being applied to the cutter tool. Typical materials include, but are not limited to, metals, such as steel and aluminum, as well as plastics, such as nylon and polycarbonate as well as plastic alloys and any combination thereof. Surface hardening compositions may also be used to treat the surface of the housing 20. The housing 20 may be any size and shape that is able to accommodate the shaft 30 and at least two cutting members 60. In preferable embodiments, the housing 20 is circular and has a diameter as small as possible so as to be able to fit into tubulars having small diameters as well as tubulars having large diameters. In some other embodiments, the housing 20 has a larger diameter to better support the cutting members 60 during the cutting of large diameter tubulars by having the cutting members 60 closer to the housing 20 during the cutting operation.

The housing 20 defines a shaft hole 140 through the housing 20. The shaft hole 140 extends through the housing 20 along a longitudinal axis of the housing 20. The shaft hole 140 is shaped to accommodate the shaft 30. In preferable embodiments, the shaft 30 fits snuggly into the shaft hole 140 defined by the housing 20 so that no movement, or minimal movement of the shaft 30 is possible except for the movement of the shaft 30 that causes the cutting members 60 to move between the cutting position and the retracted position. The shaft hole 140 may have a uniform cross-section along the length of the shaft hole 140 or may have a non-uniform cross-section along the length of the shaft hole 140. For example, the shaft hole 140 may be defined by the housing 20 where the housing 20 has a threaded portion for engaging with a thread on the operating end 40 of the shaft 30 resulting in a generally circular cross-section and then, moving along the longitudinal axis of the housing, shaft hole 140 is defined by the housing 20 as a rectangular shape cross-section which snuggly accommodates the guide end 50 of the shaft 30. It will appreciated that a variety of shapes in various sections of the shaft hole 140 may be accommodated by various embodiments of the present invention.

The housing 20 also comprises at least two cutting member slots, which slots are operable to accommodate the cutting members 60. The housing 20 reduces or eliminates movement of the shaft 30 and the cutting members 60 in undesirable directions. In some preferred embodiments, the desired movement of the shaft 30 is along the longitudinal axis of the housing 20 and shaft 30 fits into the shaft hole 140 in a manner that enables easy movement along the longitudinal axis of the housing 20. In some preferred embodiments, the desired movement of the cutting members 60 is towards and/or away from the housing 20 in a direction that is perpendicular or generally perpendicular (i.e. precisely perpendicular is not required and a variation of about 5% to about 10% is acceptable) to the longitudinal axis of the housing 20. In these latter embodiments, a cap and head portion 90 of the housing 20 is often used.

A cap and head portion 90 of the housing 20, comprises a head section 100 and a cap section 110. The head section 100 defines cutting member slots and within each cutting member slot a single cutting member 60 is able to fit snugly. The cap section 110 encloses the cutting member slots along one side thereby creating cutting member holes 150, resulting in the movement of the cutting members 60 relative to the housing 20 being restricted to movement of the cutting members 60 towards and/or away from the housing 20 in a direction that is perpendicular or generally perpendicular to the longitudinal axis of the housing 20. In some embodiments, the cap and head portion 90 is separable from the remainder of the housing 20 and the cap section 110 is separable from the head section 100. Often fasteners, such as screws, bolts, pins, etc. are used to hold the cap section 110 together with the head section 100 and also to hold the cap and head portion 90 to the remainder of the housing 20. This arrangement facilitates easy access, for example for repair and/or maintenance, to the cutting members 60, the cutting means 70, and the engagement means 80. Further, having the cap and head portion 90 separable from the remainder of the housing 20 means that replacement of all cutting members 60 at the same time is readily achieved by separating the cap and head portion 90, from the remainder of the housing 20, together with the cutting members 60 within the cutting member holes 150 and then replacing it with a new cap and head portion 90 having new cutting members 60 within the cutting member holes 150 of the replacement cap and head portion 90. Further, a replaceable cap and head portion 90 is also beneficial in circumstances where the cut to be made is further underground or less further underground. The cap and head portion 90 may be moved from a longer housing 20 to a shorter housing 20 when a less further underground cut is to be made or may be moved from a shorter housing 20 to a longer housing 20 when a further underground cut is to be made.

In embodiments of the present invention, the shaft 30 may be any material that is suitably strong enough to withstand the forces being applied to the cutter tool 10. Typical materials include, but are not limited to, metals, such as steel and aluminum, as well as plastics, such as nylon and polycarbonate, or any combination thereof. The shaft 30 has an engagement end 40 and a guide end 50. The engagement end 40 is generally shaped so that it fits snuggly into the shaft hole 140. Often the engagement end 40 of the shaft 30 has a rectangular shaped cross-section. In preferred embodiments, the shaft 30 may have a circular shaped cross-section and in some cases may or may not be threaded. When threaded, the thread engages with a corresponding thread on the housing 20. Rotation of the engagement end 40 of the shaft 30 in a first direction, for example in a clockwise direction, relative to the housing 20 results in movement of the cutting members 60 from a retracted position to a cutting position. This may be achieved by holding the operating end 40 of the shaft 30 in a stationary position and rotating the housing 20 in a counterclockwise direction or may be achieved by holding the housing 20 in a stationary position and rotating the operating end 40 of the shaft 30 in a clockwise direction or may be achieved by rotating the operating end 40 of the shaft 30 in a clockwise direction and rotating the housing 20 in a counterclockwise direction. Since rotation of the housing 20 result in rotation of the cutting members 60, it will be appreciated that a biasing means for biasing the cutting members 60 in the cutting position may be readily achieved by either of the alternatives above that have counterclockwise rotation of the housing 20. Often it is preferable to using the biasing means to bias the operating end 40 of the shaft 30 in the clockwise direction. Similarly, once the cutting is completed, rotating the housing in a clockwise direction and/or rotating the operating end 40 of the shaft 30 in a counterclockwise direction will move the cutting members 60 to a retracted position for easy removal of the cutter tool from the tubular.

In other embodiments, the operating end 40 of the shaft 30 is not threaded and in these embodiments it is often that applying a force to the operating end 40 of the shaft 30 in the direction towards the guide end 50 along the longitudinal axis of the housing 20 will result in the cutting members moving to a cutting position. In such embodiments, a biasing means may be used to bias the operating end 40 in the first direction, for example towards the guide end 50 along the longitudinal axis of the housing 20, in order to keep the cutting means 70 engaged with tubular.

The guide end 50 of the shaft 30 may be shaped like a spear head or an axe head, where a point of the guide end 50 is the portion of the guide end 50 that is most distant from the operating end 40 and the guide end 50 extends towards the operating end 40 with incrementally increasing cross-sectional area until it meets the operating end 40. In preferred embodiments, the guide end 50 of the shaft 30 is a spear head body. The point of the spear head body may be a small edge like an axe or a point like a pin or spear. Such embodiments are termed herein as a "spear head body".

In some embodiments, the operating end 40 has a similar cross-sectional area as the cross-sectional area of the guide end 50 where it meets the operating end 40. In other preferred embodiments, the operating end 40 has a cross- sectional area that is generally circular and consistent across its length and embeds into a larger cross-sectional area of the guide end 50. In some of these preferred embodiments, the cross-sectional area of the guide end 50 is rectangular and the nature of the embedding of the operating end 30 into the guide end 50 permits rotation of the operating end 40 relative to the guide end 50, but does not permit the two ends to separate from each other. A non-limiting example of this type of embedding is where the operating end 40 comprises a circular groove around the circumference of the operating end 40 and the groove is not at the very edge of the operating end 40. In these embodiments, the guide end 50 defines a hole into which the portion of the operating end 40 between the very edge and the groove may fit. The guide end 50 defines the hole such that a portion of the guide end 50 is able to engage with the groove in the operating end 30 thereby holding the two ends together.

In other embodiments still, the embedding does not permit rotation of the two ends relative to each other. In other embodiments still, the shaft 30 is a threaded rod and has a consistent, generally circular cross-sectional area across the entire length of the shaft 30, including engagement end 40 and guide end 40. In these embodiments, the thread of the shaft 30 engages with the threaded portion of the housing 20 and also engages with a thread on the engagement means 80 of the cutting member 60.

The shaft 30 is also shaped at the guide end 50 so that it has at least one key 120 that is operable to engage with the engagement means 80 on the cutting member 60. Each key 120 is operable to engage at least one of the cutting members 60. Each key 120 may be any shape in cross-section, but the key 120 extends along the complete length of the guide end 50, or most of the length of the guide end 50. Often the cross-sectional shape of the key 120 is square or rectangular and is often consistent across its length. In some other embodiments the key 120 is a single key 120 and is a thread on the shaft 30. In embodiments in which the key 120 is a thread, the same, single key 120 is able to engage with all of the cutting members 60 via the engagement means 80.

Cutting members 60 suitable for use in the present invention comprise any cutting means 70 known to a person of skill in the art suitable for cutting tubulars coupled to an engagements means 80. Non-limiting examples of cutting means include, high pressure water cutters, high pressure sand cutters, cutting edges, like blades and cutting wheels, etc., flame based cutters, abrasive cutters, such as grinding wheels, diamond dust cutters garnet dust cutter, etc. The engagements means 80 may be any material that is suitably strong enough to withstand the forces being applied to the cutter tool. Typical materials include, but are not limited to, metals, such as steel and titanium. The engagement means 80 engages with both the cutting means 70 and the guide end 50 of the shaft 30. The engagement means 80 engages with the cutting means 70 by holding the cutting means 70. The engagement means 80 engages with the guide end 50 of the shaft 30 via the key 120 on the shaft 30. The engagement means defines a keyway 130 into which the key 120 from the shaft 30 fits snuggly. The keyway 130 has the same cross-sectional shape as the key 120, and corresponds to the key 120. In some cases the keyway 130 is a thread that engages with the thread on the shaft 30. In some embodiments, the engagement means 80 may hold the cutting means 70 so that replacement of the cutting means 70 is possible. Cutting means 70 is often held by engagement means 80 by means of a faster, such as a bolt, pin, screw, etc. In other embodiments replacement of a worn out or defective cutting means 70 requires replacement of the whole cutting member 60.

A cutting member 60 is operable to be in a retracted position or in a cutting position. The retracted position is a position where the cutting means 70 on the cutting member 60 is not engaged with a tubular to be cut. The cutting position is a position where the cutting means 70 on the cutting member 60 is engaged with the tubular to be cut. It will be appreciated that, depending on the size of the tubular, a cutting position with respect to one particular tubular will be a retracted position with respect to another particular tubular. One particular retracted position is the fully retracted position where the cutting member 60 is inside the perimeter of the housing 20.

The cutting means 70 may be fully, partially or not at all within the perimeter of the housing 20. The housing 20 comprises at least two cutting member slots within which the cutting members 60 are able to fit snugly. The housing 20 has a perimeter, which perimeter includes a notional portion of the housing where the cutting member slots are. When the cutting member 60 is in the fully retracted position, the cutting means 70 does not protrude from the housing 20 and is within the perimeter of the housing 20, even though the cutting means 70 may be visible from outside the housing 20. Movement of the shaft 30 moves the cutting member 60 either closer to or further from the fully retracted position. Moving the cutting member 60 further from the fully retracted position results in the cutting means 70 protruding from the housing 20, protruding more from the housing 20, or being further from the housing 20. Moving the cutting member 60 closer to the fully retracted position results in the cutting means 70 not protruding from the housing 20, protruding less from the housing 20, or being closer to the housing 20. In some embodiments, the cutter tool 10 does not have a fully retracted position as the cutting means 70 are always protruding from the perimeter of the housing 20 or fully outside of the perimeter of the housing 20. In these latter embodiments, it may be helpful to understand a notional fully retracted position which is position that is not possible to achieve, but may be understood as a reference point when referencing the fully retracted position.

Cutter tools according to the present invention comprise at least two cutting members 60. The use of multiple cutting members 60 results in reduced incidents in which the housing 20 of the cutter tool 10 comes into contact with the tubular during a cutting operation. This reduces ware on the cutter tool 10 and results in easier cutting. Cutting is faster and the amount of rotation of the tool is reduced with the use of more cutting members 60. Further, when a tubular is cut, each cutting means 70 is used less resulting in less ware to the cutting means per tubular cut resulting in less maintenance per tubular cut.

The at least two cutting members 60 are situated within cutting member slots in the housing 20. The cutting member slots are positioned on the housing such that there is generally about an equal distance between all of the cutting members 60 on the cutter tool 10. This arrangement of cutting members 60 permits for a more balanced and centered position of the cutter tool 10 during operation. Each of the cutting members 60 on the cutter tool 10 interact with the same shaft 30 and movement of the shaft 30 results in an equal amount of movement to each cutting member 60 with respect to movement of the cutting member 60 closer to or farther from the housing 20. In other words, movement of the shaft 30 moves all of the cutting members 60 further from the housing 20 by the same amount of distance or closer to the housing 20 by the same amount of distance. By moving all of the cutting members 60 the same amount of distance to and from the housing 20, it is possible to achieve a more centered and balanced position within the tubular for the cutter tool 10 during the cutting operation.

In particular embodiments of the present invention, cutter tools 10 comprise an operating body. An operating body is any device that is operable to move the shaft 30. In some embodiments, the operating body comprises a motor operatively coupled to the shaft 30. The motor is often a drive motor. In other embodiments, the operating body is simply an extension of the operating end 40 of the shaft 30. In other embodiments, the operating body is a hydraulic system which may be operatively coupled to the shaft 30 directly or operatively coupled to the extension of the shaft 30. In other embodiments, the operating body is a pneumatic system which may be operatively coupled to the shaft 30 directly or operatively coupled to the extension of the shaft 30. In some embodiments the operating body also acts as a biasing means to bias the shaft 30 towards movement of the shaft 30 causing the cutter members 60 to be in the cutting position.

When in operation, the cutter tools of the present invention are able to be inserted into a tubular to be cut. In order for the cutter tool 10 to be inserted into the tubular to be cut, the cutting members 60 must be in the retracted position, and often are in the fully retracted position. Once in the tubular, the shaft 30 is moved so that the cutting members are moved from the retracted position to the cutting position. The cutting position is the position when the cutting means 70 are engaged with the tubular to be cut. Once the cutting means 70 are engaged with the tubular to be cut, the cutter tool 10 is rotated, thereby cutting the tubular. As the cutter tool 10 rotates, the cut in the tubular is made and often the cutting means 70 need to be moved further from the housing 20 (i.e. closer to the tubular) in order to maintain engagement between the cutting means 70 and the tubular. In some embodiments, this is achieved by using a biasing means to bias the shaft 30 towards movement that results in the cutting members 60 moving further from the housing 20. The biasing means may be a pneumatic or a hydraulic system that maintains a force on the shaft. Alternatively, the biasing means may simply be an operator applying force to the shaft. The biasing means may be a motor operable to rotate the shaft 30, the housing 20 and/or both the shaft 30 and the housing 20. The motor is often a mud motor. The biasing means may or may not be a part of the operating body.

Rotation of the cutter tool 10 may be achieved by means of a motor, a user rotating the cutter tool 10, a hydraulic system, or a pneumatic system. In some embodiments of the present invention, the cutter tools are operatively coupled to a rotation means for rotating the cutter tool 10. A rotation means is any device that is operatively coupled to the cutter tool 10 so that the cutter tool 10 may be rotated by the rotation means. In some embodiments, the rotation means is a motor operatively coupled to the housing 20.

Although various embodiments of the invention are disclosed herein, many adaptations and modifications may be made within the scope of the invention in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the invention in order to achieve the same result in substantially the same way. Numeric ranges are inclusive of the numbers defining the range. Furthermore, numeric ranges are provided so that the range of values is recited in addition to the individual values within the recited range being specifically recited in the absence of the range. The word "comprising" is used herein as an open-ended term, substantially equivalent to the phrase "including, but not limited to", and the word "comprises" has a corresponding meaning. As used herein, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a thing" includes more than one such thing. Citation of references herein is not an admission that such references are prior art to the present invention. Furthermore, material appearing in the background section of the specification is not an admission that such material is prior art to the invention. Any priority document(s) are incorporated herein by reference as if each individual priority document were specifically and individually indicated to be incorporated by reference herein and as though fully set forth herein. The invention includes all embodiments and variations substantially as hereinbefore described and with reference to the examples and drawings.