Patent Application
20100288509
The present invention relates, generally, to an apparatus and methods used to apply torque to a sucker rod connection or a similar connection between tubular segments.
Conventionally, strings of sucker rods are used to facilitate production of a well after a significant amount of production has taken place. As a supply of hydrocarbons is depleted through typical production, the pressure within a well reservoir can become insufficient to transport the hydrocarbons to the surface without the assistance of a pump. In these instances, a downhole pump is lowered into the well, attached to the lower end of a sucker rod string. The upper end of the sucker rod string is then attached to a pump jack or similar reciprocating surface apparatus, which uses the sucker rod string to drive the downhole pump, enabling continued production of the well.
Typically, a sucker rod string is formed from multiple segments of rod with threaded ends, each a uniform length, that are threaded together using connectors between each segment. The end of each rod segment is threaded into one side of a connector, and torqued to ensure a secure connection, then as the sucker rod string is lowered, additional rod segments and connectors can be added and torqued. Normally, a tong device is usable to form connections between rod segments. A typical rod tong is a hydraulic device, similar in design to the tong devices used to grip and torque segments of tubing and other oilfield tubulars. Most tong designs include a primary gripping device used to engage an upper rod segment and a secondary or back-up gripping device used to engage the connector or a lower rod segment. The primary gripping device rotates the upper rod segment while the back-up gripping device retains the connector or lower rod segment in a stationary position, thereby allowing formation of the connection. When the sucker rod string is removed from the well, the same rod tong, or a similar device, is normally used to break the sucker rod connections by rotating each segment in the opposite direction.
As demand for hydrocarbons increases throughout the world, use of non-conventional oil reserves, such as heavy-oil deposits, has been more frequently undertaken. Heavy-oil deposits are normally shallow and contain thicker, heavier oil compared to that found in conventional reservoirs. Development of heavy-oil reserves has become more economical through the use of horizontal drilling and the use of progressive cavity pumps, which are specifically adapted to lift the heavier oil. Progressive cavity pumps utilize a rotor-stator type pump that is rotated by a string of sucker rods, rather than actuated through simple vertical reciprocation. Due to the high rate of production of these wells, large diameter tubing and large diameter sucker rods are utilized, with the sucker rods having a diameter as large as 1.5 inches.
The constant rotation and flexion of the large diameter sucker rods as they drive the progressive cavity pump applies torque to the sucker rod connections and causes the sucker rod connections to become extremely tight. When the sucker rod string is removed from a well, these high torque connections are extremely difficult to break. Due to the additional torque applied to the connections during operation of the pump, a standard hydraulic rod tong does not provide enough torque to disassemble the sucker rod string. Even the most high-torque rod tongs are inadequate for this purpose. Attempts to use conventional rod tongs to break these connections often causes damage to the tong device. The sucker rod connections can be manually struck with hammers or similar tools to facilitate their disassembly, however this method is inefficient, time-consuming, unreliable, and dangerous, often causing damage to the rod segments and rod connectors, and accidents and injuries among the operators. Pipe wrenches are also usable to break the rod connections; however, this method is equally dangerous and time-consuming.
A conventional tubing tong is used to provide extremely high torque to segments of tubing, in excess of what would be required to break these tightened sucker rod connections, however a tubing tong is unable to grip and apply torque to objects having a diameter as small as that of the sucker rods. It would be desirable to adapt an existing tubing tong, which would be readily available at most production sites, to torque sucker rod connections, without requiring extensive modifications to the tubing tong, thereby enabling a single tool to be utilized for torquing both tubing segments and sucker rod connections.
As such, a need exists for an apparatus and method that can provide sufficient torque to break a large diameter sucker rod connection without causing damage to equipment or injury to crew members.
A need also exists for an apparatus and method that can adapt a conventional tubing tong for use with sucker rods, thereby eliminating the need for a separate rod tong at a worksite, while enabling application of the high torque capabilities of the tubing tong to sucker rod connections.
A further need exists for an apparatus and method that is simple to construct, install, and remove, enabling a single tubing tong to be interchangeably, economically, and efficiently used for multiple purposes.
The present invention meets these needs.
The present invention relates, generally, to an apparatus and method usable to apply torque to a connection between tubulars using a tong device intended for use with a first type of tubular, the tong device being fitted with an insert that configures the tong device to apply torque to a second type of tubular having a diameter smaller than that of the first type of tubular.
In a specific, preferred embodiment, the present invention relates to an apparatus and method usable to apply torque to a sucker rod connection. Specifically, the apparatus includes an insert adapted for engagement with a tong device. The insert can be sized for engagement with a tubing tong intended for use in providing torque to an oilfield tubular, which can include any conventional open-face tong or similar tong device. The tong device can include an opening and one or more gripping members disposed therein, the tong being adapted to apply torque to objects extending through the opening and secured by the gripping members.
In the preferred embodiment of the invention, the insert can include an upper flange connected to a tubular body, which is connected to a lower engagement member. The three parts of the insert can be formed as a one-piece construction, or the insert can be assembled using multiple parts, such as by welding.
The upper flange is adapted to be secured to the tong device, proximate to the opening, such as within the drive head of the tong. In an embodiment of the invention, the upper flange can include one or more lugs configured for engagement with corresponding slots in the tong device.
The tubular body of the insert extends through the opening of the tong device when the insert is installed, such that the tubular body is engaged by the gripping members of the tong when in place. In an embodiment of the invention, the tubular body can be formed from a portion of an oilfield tubular, such as a piece of production tubing. In instances where the high torque from the tong may cause bending or warping of the tubular body, a stronger material, such as a piece of tubing with thicker walls can be utilized. Embodiments of the invention where the engagement between the tubular body and the tong device are sufficient to support and apply torque to the insert do not require the upper flange, as described above, and as such, in these embodiments of the invention, the upper flange can be omitted.
The lower engagement member can include a thick piece of steel, or a similar durable material, having a slot cut therethrough sized to engage a segment of a sucker rod string.
The upper flange, tubular body, and lower engagement member can have a side opening extending along the axial length of the insert, for permitting lateral engagement of the insert with a sucker rod segment. When the insert is engaged with the tong device, the side opening can be aligned with a similar opening in the tong device to accommodate the sucker rod segment.
In operation, torque from the tong device can be applied to the insert through the connection between the upper flange and the tong device and/or through the engagement between the gripping members of the tong and the tubular body of the insert. The insert then transfers this torque to a sucker rod segment through the engagement between the lower engagement member and the sucker rod segment. The thickness of the engagement member enables the lower engagement member to withstand the torque provided to the sucker rod segment.
In an embodiment of the invention, a back-up tong device can be used in conjunction with the tong device and insert, the back-up tong having a lower opening adapted to engage a second sucker rod segment connected to the segment of rod engaged with the insert. The back-up tong can be movably and/or removably secured to the tong device. Preferably, the back-up tong can include a movable engagement member having the lower opening disposed therein, enabling the back-up tong to be used to engage the second sucker rod segment from multiple directions, as needed. At times, an upper sucker rod segment can become rotationally misaligned with a lower sucker rod segment, requiring that the lower opening of the back-up tong be movable, rather than in fixed alignment with the slot in the insert. In an alternate embodiment of the invention, the back-up tong can be rotationally fixed and engaged with a lower sucker rod segment while the tubing tong and/or the insert can be rotated or pivoted to align with the upper sucker rod segment. In a further embodiment of the invention, both the back-up tong and the tubing tong and/or insert can be movable accommodate a desired alignment between adjacent sucker rod segments.
The present invention thereby provides a simple and efficient means by which a conventional tong device can be adapted to provide torque to a sucker rod connection, or another type of tubular connection, including the high torque required to break a large diameter sucker rod connection used to actuate a progressive cavity pump, without risking damage to equipment or injury to personnel. Further, through use of the present invention, the need for a rod tong specifically manufactured for use with sucker rod segments can be eliminated, a single tong device being usable to torque both sucker rod segments and other oilfield tubulars of varying sizes.
In the detailed description of the embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
The depicted embodiments of the invention are described below with reference to the listed Figures.
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that the embodiments can be practiced or carried out in various ways.
Referring now to
The flange (12) is depicted as a generally round piece of steel, or a similar durable material, having a diameter and a thickness sized to fit within the drive head of a tubing tong or similar tong device. The shape and dimensions of the flange (12) can vary depending on the tong device within which the insert (10) is to be installed. Placement of the flange (12) within an appropriate corresponding location on a tong device stabilizes the insert (10) such that the tong device can be used to apply torque effectively, without dislodging the insert (10) or causing damage to any components. The flange (12) is shown having a generally central opening (18) for accommodating a sucker rod segment, which in operation, passes through the flange (12), tubular body (14), and engagement member (16), approximately along the longitudinal axis of the insert (10). The flange (12) is also shown having two holes (20, 22), used to accommodate lugs or similar attachment members, for securing the flange (12) to the tong device, thereby securing the insert (10) in an operative position. In embodiments of the invention where engagement between the tubular body (14) and the tong device is sufficient to support the insert (10) and apply sufficient torque to form and/or break a sucker rod connection, the flange (12) can be omitted.
The tubular body (14) is depicted as a hollow, generally cylindrical piece of steel, or a similar durable material, welded to the flange (12). The tubular body (14) can have a length and diameter sized to fit within the opening of a tubing tong or similar tong device and engage at least one gripping member of the tong. The shape and dimensions of the tubular body (14) can vary depending on the tong device within which the insert (10) is to be installed. In an embodiment of the invention, the tubular body (14) can be a cut segment of drill pipe, or of a similar oilfield tubular normally engaged by one or more gripping members of the tong device during normal operations. In embodiments of the invention where extremely high torque is to be applied to the insert (10) by the tong device, and a conventional segment of drill pipe may become twisted or otherwise deformed, a more durable tubular body, such as a segment of a thick-walled oilfield tubular or a tubular body specifically designed for use within the insert (10) can be utilized. When the insert (10) is operatively positioned within a tong device, the tubular body (14) extends through the opening of the tong device to engage one or more gripping members of the tong, while a segment of a sucker rod string extends axially through the hollow center of the tubular body (14).
The engagement member (16) is depicted as a thick, generally round piece of steel, or a similar durable material, welded to the tubular body (14). While the flange (12), tubular body (14), and engagement member (16) are shown as individual members, welded together to form the insert (10), in various embodiments of the invention, the insert can be a one-piece construction, a two-piece construction, or the individual parts of the insert (10) can themselves contain multiple parts welded or otherwise connected together, such that the insert is a multi-part construction containing any number of connected parts.
The thickness and diameter of the engagement member (16) can vary depending on the type, size, shape, and nature of the tong device within which the insert (10) is to be installed, and the type, size, shape, and nature of the sucker rod string or other tubular string that the insert is adapted to engage. The engagement member (16) includes a slot (24) formed therein, the slot (24) having dimensions sufficient to securely engage a segment of a sucker rod string or other tubular. While
The flange (12), tubular body (14), and engagement member (16) are each depicted having a side or lateral opening formed therein, which provide the insert (10) with a continuous side opening (26) for permitting lateral engagement of the insert (10) with a sucker rod string. When the insert (10) is operatively installed within an open-face tong device, the side opening (26) aligns with the lateral opening of the tong to accommodate the sucker rod string.
In operation, the depicted insert (10) can be positioned within a tong device such that the tubular body (14) passes through the tong opening and is engaged by one or more gripping members of the tong, while the flange (12) rests within the drive head of the tong or a similar region of the tong device shaped to engage the flange (12). The flange (12) can be fitted with one or more lugs configured for engagement with complementary slots in the tong device. The tong device and installed insert (10) are then laterally engaged with a sucker rod string or other tubular string, such that a segment of the tubular string passes through the side opening (26) of the insert (10) and is engaged within the slot (24) of the engagement member (16). Torque is then applied by the tong device and is transferred to the insert (10) through the engagement between the tong and the flange (12), and/or through the engagement between the gripping members of the tong and the tubular body (14). The torque applied to the insert (10) is then transferred to the engaged sucker rod or other tubular segment through the engagement member (16).
Referring now to
The tong device (28) is depicted as a conventional tubing tong having a drive head region (30), an engagement opening (32) usable to engage and torque oilfield tubulars enclosed using a hinge door to fully enclose an oilfield tubular engaged within the engagement opening (32). While
The insert (10) is depicted having the flange (12) situated within the drive head region (30) of the tong device (28). The holes (20, 22) are usable to install lugs or similar attachment members to further stabilize the insert (10) within the tong device (28), such that the insert (10) does not become dislodged during operation of the tong device (28).
The tubular body (14) of the insert (10) extends through the engagement opening (32) of the tong device (28) when the insert (10) is installed in an operative position. The engagement member (16) is shown disposed beneath the tubular body (14), having a slot (24) therein for engaging a sucker rod segment or another type of tubular segment having a diameter smaller than that intended for engagement with the tong device (28). When installed within the tong device (28), the side opening (26) of the insert aligns with the side of the engagement opening (32) coverable by the hinge door to enable lateral engagement of the tong device (28) and insert (10) with a sucker rod string or other tubular string.
Other types and configurations of securing members between the tong device (28), back-up tong device (36), and insert (10) are also usable. Further, in an embodiment of the invention, securing members between the back-up tong device (36) and the insert (10) and/or the tong device (28) can be omitted, and the back-up tong device (28) can be freestanding or otherwise positioned operatively for engagement with a sucker rod string or other tubular string.
In operation, a sucker rod string can be laterally engaged by the tong device (28) and insert (10) through the side opening (26), such that an upper segment of the sucker rod string is engaged by the slot (24) within the engagement member (16) of the insert (10). Simultaneously, the movable member (44) of the back-up tong device (36) can be pivotably moved about the pivot point (50) such that the lower slot (46) aligns with a lower segment of the sucker rod. The pivotable movement of the movable member (44) enable the depicted apparatus to be used to simultaneously engage two segments of a sucker rod string that are not in rotational alignment by enabling the lower slot (46) to be moved out of alignment with the slot (24) of the engagement member (16) to engage a lower segment of the sucker rod string. In other embodiments of the invention, the back-up tong device (36) can lack a movable member (44) and the tong device (28) and/or the insert (10) can be rotatably or pivotably movable to enable alignment with an upper segment of a sucker rod string while the lower slot (46) remains fixed. In further embodiments of the invention, both the back-up tong device (36) and the tong device (28) and/or insert (10) can be pivotably or rotatably movable to accommodate any misalignment between adjacent sucker rod segments.
Once a sucker rod string has been engaged by both the insert (10) and the back-up tong device (36), the tong device (28) can be used to apply torque to the insert (10), which transfers the torque to a sucker rod segment engaged within the slot (24). Simultaneously, the back-up tong device (36) retains a lower sucker rod segment and/or a sucker rod connector in a stationary orientation, enabling the torque applied to the upper rod segment to form or break the sucker rod connection.
As described above, the present invention thereby provides an efficient method by which a tong device, such as a tubing tong, can be adapted to torque a sucker rod connection or other tubular connection, with sufficient torque to break connections formed between large diameter sucker rod connections used to drive progressive cavity pumps. Further, the present invention eliminates the time required and the risk of damage and injury inherent in the breakdown of highly torqued sucker rod connections. Additionally, the present invention eliminates the need for a separate rod tong at a work site by enabling a tubing tong or similar tong device to be quickly and simply adapted to torque sucker rod connections, and reverted to torque connections between other oilfield tubulars of varying sizes, as needed.
While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.
