Anchor apparatus and method

Abstract

Anchor apparatuses and methods for anchoring a tool within a wellbore are disclosed. An anchor apparatus can include an operator, such as an electrical motor, a hydraulic source, or other similar sources of motion, to cause movement of a rod between a first and second position. A plurality of arms pivotally secured to the apparatus are movable between a retracted position and an extended position. Movement of the rod from the first position to the second causes the rod to pivot the arms toward the extended position. Computer instructions can be utilized to cause automatic retraction of the arms upon receipt of a command after a selected interval of time has lapsed to prevent attempted removal of the apparatus while the arms are extended. The anchor apparatus can also include a frangible member provided with a selected tolerance to enable removal of the apparatus without retraction of the arms.

Description

FIELD

The present invention relates, generally, to anchor apparatuses and methods for anchoring and/or maintaining a position of a tool within a wellbore.

BACKGROUND

When producing a well, or performing other downhole operations, a large variety of extreme pressures and other forces within the wellbore environment affect the apparatuses lowered into the well, as well as the tool strings, wirelines, slicklines, or other conduits used to lower these apparatuses. Additionally, actuation of various downhole tools can cause changes in downhole pressure, and can create forces that catastrophically entangle or otherwise badly damage the tools and their associated conduits. For example, when producing a well, a perforating gun is typically actuated to create multiple perforations within a segment of casing and sections of the borehole external to the casing. This operation can create a region of high pressure at the site of the perforation, which can forcibly move the perforating gun in an uphole direction, breaking and/or entangling the wireline, slickline, tool string, or other conduit used to lower the perforating gun. Remedial fishing and/or clean-up operations to correct such a situation can be extremely costly and time consuming and can halt production of a well for a significant length of time.

To prevent undesired movement of a tool caused by downhole forces, anchor devices are typically engaged with a perforating gun or other perforating apparatus prior to lowering the apparatus into the wellbore. Additionally it is often desirable to retain other types of tools, such as production logging tools, at a generally fixed location within a wellbore while flowing the well pressure toward the surface. Conventional anchor devices typically include a body sized to pass through any restrictions between the surface and the desired position for the tool, having one or more arms or slip segments movable between a retracted position within the body and an extended position to engage the wellbore. Most anchor devices are mechanical in nature, having arms or slip segments that move outward to engage the wellbore responsive to sudden or significant uphole velocity, preventing further uphole movement before significant damage is incurred. Other anchor devices use actuatable sleeves or mandrels to physically bias arms or slip segments in an extended position to engage the wellbore prior to actuating the perforating apparatus.

A need exists for an anchor apparatus and method for anchoring and/or maintaining a position of a tool within a wellbore that provides improved reliability and simplicity over conventionally available anchor devices, while incorporating use of back-up methods of removal when standard disengagement from the internal surface of a wellbore is unsuccessful or impossible, and use of automatic safety features for preventing attempted retrieval of the anchor apparatus when engaged with the interior surface of a wellbore.

The present invention addresses these needs.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of the embodiments of the invention presented below, reference is made to the accompanying drawings, in which:

FIGS. 1-14 depict a partial cross-sectional view of an embodiment of an anchor apparatus usable within the scope of the present disclosure. Each successive figure depicts a portion of the embodiment of the anchor apparatus disposed generally adjacent to that shown in the preceding and following figures.

FIG. 15A depicts an embodiment of a rod, piston, and/or mandrel usable within the anchor apparatus of FIGS. 1-14 for biasing of the arms to engage a wellbore.

FIGS. 15B and 15C depict embodiments of movable arms usable within the anchor apparatus of FIGS. 1-14 for engagement with an interior surface of a wellbore.

FIG. 16A depicts a diagrammatic view of an embodiment of an anchor apparatus usable within the scope of the present disclosure disposed in a disengaged position.

FIG. 16B depicts the anchor apparatus of FIG. 16A disposed in an engaged position.

The depicted embodiments of the invention are described below with reference to the listed Figures.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Before explaining the disclosed embodiments of the invention in detail, it is to be understood that the present invention is not limited to the particular embodiments depicted or described, and that the invention can be practiced or carried out in various ways.

The preset invention relates, generally, to anchor apparatuses and methods for maintaining a position of a tool, such as a perforating, cutting, or isolation apparatus, a production logging apparatus, or other types of downhole tools, within a wellbore, before, during, and after actuation of the tool, and during production of a well. Embodiments of the anchor apparatus can include a tubular body having one or more connections, such as a threaded pin or box end, for engagement with one or more tools, and an internal rod, piston, cylinder, and/or mandrel moveable within the body. An operator, which can include a hydraulic source, an electrical motor, or any other source of locomotive force, including pneumatic, fluid-driven, and/or mechanical sources, can be in operative communication with the rod, such that actuation of the operator causes movement of the rod within the tubular body between a first position and a second position.

A plurality of arms pivotally secured to the tubular body are movable between a retracted position within or proximate to the body, and an extended position for engagement with the interior surface of a wellbore. A biasing member, such as one or more springs, can be provided in association with the arms, such that the arms are normally biased toward their retracted position. Movement of the rod from the first position to the second position causes contact between the rod and the arms, such that the arms are urged into their extended position for engagement with the interior surface of the wellbore. While the rod is retained in the second position, the arms can be maintained in their extended position against the force exerted by the biasing member. Forces caused by actuation of the tool and/or other forces within the wellbore are thereby unable to undesirably move the anchor apparatus or the attached tool due to the engagement between the arms and the interior surface of the wellbore. When retrieval of the anchor apparatus and/or the tool is desired, the arms can be retracted by actuating the operator to move the rod axially from the second position to the first position, such that the biasing member can return the arms to their retracted position.

In an embodiment of the invention, a frangible member, such as a shear ring, screw, and/or pin, can be provided at one end of the arms, the frangible member being provided with a preselected tolerance that exceeds forces within the wellbore, but is less than a force sufficient to damage the arms. When it is undesirable, unsuccessful, or impossible to cause retraction of the arms from the interior surface of the wellbore, sufficient uphole force can be applied from the surface, in any manner known in the art, to shear the frangible member, enabling retrieval of at least a portion of the anchor apparatus and removal of the wireline, slickline, tool string, or other carrier from the wellbore.

Embodiments of the invention can further include circuitry within the anchor apparatus, in communication with a processor, such that the processor causes actuation of the operator to move the rod, to thereby extend and retract the arms, responsive to receipt of a command. For example, a command from the surface can be transmitted to the processor using a wireline, to selectively cause extension and/or retraction of the arms. Alternatively, a slickline memory tool or similar downhole apparatus can be sued to cause actuation of the anchor apparatus, such that no communication or signal to or from the surface is required. For example, a memory tool can be programmed to cause actuation of the anchor apparatus when the tool is lowered to a preselected downhole location where it is desirable to engage in logging operations, perforating, cutting, or other downhole operations. In other embodiments of the invention, a memory tool can be programmed to cause actuation of the anchor apparatus when pressure from the well becomes equal to or exceeds the weight of the tool string or other carrier.

Further embodiments of the invention can include use of an automatic safety feature. When performing certain downhole operations, a significant length of time can elapse between extension and retraction of the arms of the anchor apparatus. It is common for a human operator to become unaware of the position of the arms, and attempted removal of the anchor apparatus while engaged with the interior surface of the wellbore can cause unnecessary damage to the anchor apparatus and associated components. In an embodiment of the invention, computer instructions in communication with the processor can instruct the processor to monitor the elapsed time between commands to extend or retract the arms. If a preselected time, such as five minutes, has lapsed since the previous command was received, the computer instructions can instruct the processor to automatically cause retraction of the arms, if extended, or to retain the arms in a retracted position, if not extended, upon receipt of the subsequent command. An indication of the engagement of this safety feature can then be provided to the operator causing transmission of the command.

As described previously, usable operators for causing movement of the rod can include, without limitation, one or more hydraulic sources, one or more electric motors, or combinations thereof. Other sources of force and/or motion, including pneumatic and other fluid-driven sources and/or mechanical sources are also usable. In an embodiment of the invention, electrical connections can be provided between an electrical motor and the processor or other portion of the tool for enabling selective transmission of current having positive polarity, negative polarity, or combinations thereof. Movement of the rod can be caused in a first direction responsive to a first polarity, and in a second direction responsive to a second polarity, enabling selective engagement and retraction of the arms, as desired.

In a further embodiment of the invention, an addressable switch can be provided in communication with the processor or another portion of the tool, such that the operator cannot be actuated until a preselected code is received, thereby preventing unintentional actuation of the anchor apparatus, and/or enabling other tools along a wireline to be actuated without causing actuation of the anchor apparatus.

In operation, a perforating or cutting tool, or another similar tool intended for use within a wellbore, such as a production logging tool, can be engaged with the anchor apparatus and lowered to a selected position within the wellbore. The rod of the anchor apparatus can then be moved within the anchor apparatus, as described above, such that the arms of the anchor apparatus extend to contact the internal surface of the wellbore. The arms can then be engaged with the wellbore, such as through application of an upward force to the anchor apparatus to cause the arms to protrude slightly into the interior surface of the wellbore. Pressure and other forces within the wellbore, including those caused upon actuation of the tool or those caused by production of the well, thereby fail to move the tool undesirably, due to the engagement between the arms and the interior surface of the wellbore. When it is desirable to retrieve the tool and/or the anchor apparatus, the arms can be disengaged from the interior surface of the wellbore, and the rod can be moved in the opposite direction to permit a biasing member to return the arms to a retracted position. If it is undesirable, unsuccessful, or impossible to actuate the operator, move the rod, and/or retract the arms, a frangible member provided with a preselected tolerance can be broken through application of an uphole force, separating at least a portion of the anchor apparatus for retrieval.

Referring now to FIG. 1, a top portion of an anchor apparatus usable within the scope of the present disclosure is shown. The depicted embodiment of the anchor apparatus includes an electrical motor, in operative association with an internal piston, which is usable to bias a plurality of arms toward an extended position. Specifically, FIG. 1 depicts a top sub (10) of the anchor apparatus, which can be adapted for engagement with any manner of tool string, wireline, slickline, or other carrier or conduit, one or more downhole tools, or other components or apparatuses, as known in the art.

The top sub (10) is shown attached to a circuit board housing (14) within which a circuit board (shown in FIG. 2) is contained, via a top sub adapter (12), which can be threaded, bolted, welded, connected using any manner of nut, screw, rivet, or other fasteners, or otherwise secured to the top sub (10) and/or the circuit board housing (14) in any manner. In further embodiments of the invention, any of the top sub (10), top sub adapter (12), circuit board housing (14), or any other portion of the anchor apparatus can be integral with one another, rather than separable parts.

Any manner of brass or other electrical contacts (16), for accommodating use of wirelines, electrical motors, and similar components, insulators (18), retaining rings, sleeves, or other retaining apparatuses (20), O-rings, liners, and/or other sealing apparatuses (22), can be disposed over, within, and/or between components of the anchor apparatus, as known in the art, to accommodate current, and to revived sufficient sealing and/or securing of parts to maintain integrity of the apparatus within a wellbore environment.

Referring now to FIG. 2, FIG. 3, and FIG. 4, a second, third, and fourth portion, respectively, of the anchor apparatus of FIG. 1 is shown. During normal operations, the portion the anchor apparatus shown in FIG. 2 is disposed downhole from the portion of the anchor apparatus shown in FIG. 1, and the portion of the anchor apparatus shown in FIG. 3 is disposed downhole from the portion depicted in FIG. 2. Similarly, the portion of the anchor apparatus shown in FIG. 4 is disposed downhole from that shown in FIG. 3.

Specifically, FIGS. 2 through 4 depict the circuit board housing (14), within which a circuit board (24) is shown. The circuit board (24) can be secured using any number of hex screws or other fasteners (26), soldering, or other means of connection, or alternatively, the circuit board (26) can be integral with the circuit board housing (14) or other portion of the anchor apparatus. In use, the circuit board (24) can receive signals, such as through a wireline (not shown) attached to and/or extending through the top sub (10, visible in FIG. 1) and adjacent portions of the apparatus. Alternatively, the circuit board (24) could receive signals from a downhole slickline memory tool, through an integral component within the anchor apparatus, or combinations thereof. An associated processor of the circuit board (24) can thereby process received signals and cause actuation of the anchor apparatus responsive to the signals. The circuit board (24) can also include any manner of associated data storage for storing computer instructions to control operations of the processor, such as implementation of a safety feature to cause retraction of the arms of the anchor apparatus if no command is received for a selected period of time, as described previously. Adjacent either end of the circuit board (24), a chassis (28) is shown, which can be secured using any manner of O-ring or similar sealing apparatus (22), or other type of fastener as known in the art. FIG. 4 also depicts a motor housing (30) within which an electrical motor (shown in FIG. 5) is disposed, which can be secured using any manner of sealing apparatus (22) or similar method of fastening or securing known in the art.

Referring now to FIG. 5, a fifth portion of the anchor apparatus shown in FIGS. 1-4 is depicted. During normal operations, the portion of the anchor apparatus shown in FIG. 5 is disposed downhole from that shown in FIG. 4. FIG. 5 depicts an electrical motor (32) disposed within the motor housing (30). The electrical motor (32) is shown disposed adjacent to and mounted using a motor mount (34), however it should be understood that any manner of connection or securing known in the art can be used to position the electrical motor (32) within the anchor apparatus. Additionally, the anchor apparatus can be understood to include any manner of wiring, electrical contacts, connections, conductors, and insulators, as known in the art, to enable the electrical motor (32) to receive electrical signals through a wireline or similar conductor, a slickline memory tool, wireless and/or remote actuation, or combinations thereof. Further, while the depicted embodiment of the anchor apparatus is shown including an electrical motor (32), it should be understood that in various embodiments of the invention, other operators are also usable, including, without limitation, one or more hydraulic sources, pneumatic sources, other fluid-driven operators, mechanical sources, or combinations thereof.

FIG. 6 depicts a sixth portion of the anchor apparatus, disposed, during normal operations, downhole from the portion of the anchor apparatus shown in FIG. 5. Specifically, FIG. 6 depicts the electrical motor (32) within the motor housing (30), adjacent the motor mount (34), which is shown secured within the anchor apparatus using one or more sealing apparatuses (22) or other fasteners or methods of attachment. The electrical motor (32) is shown operatively engaged with a drive shaft (36) via a motor attachment (38), the drive shaft being operable to drive or otherwise impart force to an internal piston (depicted in subsequent Figures) or other portion of the anchor apparatus. FIG. 6 also depicts a transmission housing (40), which contains various components of a transmission system associated with the electrical motor (32).

Referring now to FIG. 7 and FIG. 8, a seventh and eight portion, respectively, of the anchor apparatus are shown, which are disposed, during normal operations, downhole from the portion of the anchor apparatus shown in FIG. 6. The motor mount (34) and additional sealing apparatuses (22) for securing the motor mount (34) are shown disposed within the transmission housing (40). The transmission housing (40) is shown including a screw (42) or similar pin or secured member within, which can include a lead screw in an embodiment of the invention, engaging the drive shaft (36) and positioned and/or movable using a screw guide (44). A busing (46) coupled with a bearing (48) facilitates relative motion between components within the transmission housing (40), as known in the art, while a nut (50) or similar fasteners can be used to secure fixed components within the transmission housing (40). Within the lower portion of the transmission housing (40), a wire guide (52), a tube (54), or combinations thereof can be used to accommodate conductors and other similar components.

Referring now to FIG. 9, a ninth portion of the anchor apparatus is shown, which can be disposed adjacent to the portion shown in FIG. 8 during normal operations. The lower portion of the tube (54) is shown within the transmission housing (40), which engages an anchor adapter (56) at its lower end, for attachment to adjacent components of the anchor apparatus. Two o-rings or similar sealing members (22) or other engaging members can be placed between the transmission housing (40) and the anchor adapter (56).

Referring now to FIGS. 10 and 11, tenth and eleventh portions of the anchor apparatus are shown, which are disposed adjacent to the portion shown in FIG. 9 during normal operations. Specifically, FIGS. 10 and 11 depict the lower end of the anchor adapter (56) disposed adjacent to a tube (58) with an endcap (60) engaged thereto. A piston (62) is disposed adjacent to the tube (58), in operative association with an actuator (64). A plurality of arms (66) are disposed adjacent to the piston (62), each of the arms (66) being pivotally attached within the anchor apparatus via a hinge pin (72) or similar member, such that when biased by the piston (62), the arms (66) are movable between a retracted position within the anchor apparatus, and an extended position that protrudes through associated openings (68) within the body of the anchor apparatus for engagement with an interior surface of a wellbore. The piston (62) can be provided in operative communication with the electric motor (32, shown in FIG. 6), such that actuation of the piston (62) using the drive shaft (36, shown in FIG. 6) of the electric motor causes axial movement of the piston (62) within the body of the anchor apparatus. Movement of the piston (62) can engage an angled surface (70) of one or more of the arms (66), such that the arms are biased through the associated openings (68) into an extended position for engagement within the wellbore. When the piston (62) is removed from engagement with the arms (66), a spring (76) or similar biasing member in communication with a movable body (74) can bias the arms (66) toward a retracted position. While the number, dimensions, and configuration of the arms (66) can be varied depending on the specific application of the anchor apparatus, in an embodiment of the invention, the anchor apparatus can include three sets of arms of differing sizes, each set of arms including three individual arms. For example, an embodiment of the invention can include a first set of three arms each having a length of about 3.5 inches, a second set of three arms each having a length of about 45 inches, and a third set of three arms each having a length of about 5.5 inches.

FIG. 15A depicts an embodiment of the piston (62) usable within the scope of the present disclosure. While the dimensions and shape of the piston (62) can vary, in an embodiment of the invention, the piston (62) can include a segment of pipe having a diameter of approximately 3.5 inches. The piston (62) is shown having a first end (96) with a diameter slightly narrow than that of a second end (98), with a tapering shoulder (100) therebetween. The second end (98) of the piston is further shown having a tapered end (102) for engagement with one or more of the plurality of arms (66).

FIGS. 15B and 15C depict embodiments of arms (66), usable within the scope of the present disclosure. While the dimensions and shapes of the arms (66) can vary, the arm (66) depicted in FIG. 15B is shown having a length of approximately 4.5 inches, and the arm (66) depicted in FIG. 15C is shown having a length of approximately 3.5 inches. Each arm (66) is shown having a generally angled surface (70), adapted for contact with the tapered end (102) or other portion of the piston (62), such that movement of the piston (62) biases the arm (66) outward from the anchor apparatus. The arms (66) are further shown having pointed ends (104), which can include tungsten carbide and/or diamond facing or inserts, as known in the art, to facilitate penetration into an interior surface of a wellbore. Each arm (66) is also shown having a bore (106) or through-hole, for accommodating a hinge pin or similar member to provide pivotal movement of the arm (66) relative to the body of the anchor apparatus.

Referring now to FIG. 12, a twelfth portion of the anchor apparatus is shown, which can be disposed adjacent to the portion shown in FIG. 11 during normal operations. The lower ends of the spring (76) and actuator (64) are shown adjacent to a locator body (78) and a shear ring (80) or similar frangible member, such as a screw or pin. Prior to lowering the anchor apparatus into the wellbore, the shear ring (80) or similar frangible member can be provided with a selected tolerance, such that when retraction of the arms (66, depicted in FIGS. 10-11) is undesired, unsuccessful, or impossible, a sufficient force provided to the anchor apparatus can shear the shear ring (80), enabling at least partial retrieval of the anchor apparatus and the wireline or other conduit used to lower the apparatus into the wellbore.

FIG. 12 also depicts a series of packing or spacing elements (82), which can include any manner nuts, spacers, or similar elements known in the art, which facilitate engagement with lower portions of the anchor apparatus. O-rings or similar sealing members (22) can be provided adjacent to and/or between any of the spacing elements (82).

Referring now to FIGS. 13 and 14, a thirteenth and fourteenth portion of the anchor apparatus, respectively, are shown, which can be disposed adjacent to the portion shown in FIG. 12 during normal operations. Specifically, the lower portion of the anchor apparatus is shown, which includes a lower adapter (88) engaged with the remainder of the anchor apparatus, having one or more O-rings or similar sealing members (22) disposed thereon. A rubber boot (84) or similar insulating member is shown adjacent to the lower adapter (88), which can be secured by a crimped contact (86) or similar conductive member. A plunger (90) is shown engaged at the lowest point of the anchor apparatus, which can be axially movable via a spring (92) or similar biasing member. Any manner of contacts (16) and/or insulators (18) are usable to electronically connect or isolate the plunger (90) and/or the lower adapter (88) as known in the art. Similarly, one or more sealing members (22), such as O-rings, are shown, in addition to a retainer ring (94), are shown securing the plunger (90) and lower adapter (88).

In use, a tool can be secured to the anchor apparatus of FIGS. 1-14, and the tool and anchor apparatus can be lowered to a selected position within a wellbore. The electrical motor (32) can be actuated, such as through use of a wire line to communicate a signal from the surface to the circuit board (24), or through use of a slickline memory tool provided in communication with the electrical motor, causing the drive shaft (36) of the electrical motor (32) to impart movement to the piston (62) within the body of the apparatus. Movement of the piston (62) biases the arms (66) into an extended position by pivoting the arms through the openings (68) in the body of the apparatus using the hinge pins (72) or similar movable members. The arms (66) can then be engaged with an interior surface of the wellbore, such as through application of an uphole force applied from the surface, which can cause the tips of the arms (66) to protrude slightly into the wellbore surface. Engagement between the arms (66) and the wellbore prevents undesired movement of the anchor apparatus and attached tool responsive to any changes in pressure or other forces within the wellbore, including pressure changes caused through actuation of the tool.

To remove the anchor apparatus and/or the tool from the wellbore, the arms (66) can be disengaged from the interior surface of the wellbore and permitted to retract through the openings (68) into the body of the apparatus by communicating a second signal, to cause the electrical motor (32) to move the piston (62) in the opposite direction. Movement of the piston (62) away from the arms (66) permits springs (76) or similar biasing members to return the arms (66) to the retracted position. In selected embodiments of the invention, movement of the piston (62) in a first selected direction can be caused using current having a first polarity, while movement of the piston (62) in the reverse direction can be caused using current having a second polarity. Alternatively, the shear ring (80) or similar frangible member can be broken, such as through application of an uphole force in excess of the tolerance of the shear ring (80), to enable removal of the apparatus from the wellbore.

In an embodiment of the invention, a processor in association with the circuit board (24) can be provided in operative communication with computer instructions that determine the amount of time that has lapsed between commands received by the processor. If a selected interval of time, such as five minutes, has lapsed, receipt of a command by the circuit board (24) can cause automatic movement of the piston (62) to retract the arms (66), if the arms (66) are disposed in an extended position, or alternately, receipt of a command by the circuit board (24) can cause no movement of the piston (62), if the arms are in the retracted position. In a further embodiment of the invention, the circuit board (24) can include an addressable switch, such that signals, commands, and/or current transmitted to the anchor apparatus will not cause actuation of the electrical motor (32) and/or movement of the piston (62) until activation of the addressable switch using a preselected address and/or code.

Referring now to FIG. 16A a diagrammatic view of an embodiment of an anchor apparatus (204) usable within the scope of the present disclosure is shown disposed within a wellbore conduit (200). It is to be understood that the wellbore conduit (200) can include any manner earthen or rock borehole, or any manner of drillpipe, casing, or other tubular member, as known in the art. Within the wellbore conduit (200), the anchor apparatus (204) is shown engaged with a downhole tool (202), which FIG. 16A depicts as a perforating tool. The anchor apparatus (204) includes a plurality of arms (206), which are shown disposed within its body. A piston (208), driven by a drive shaft (210) of a motor or similar operator, is useable to contact and bias the plurality of arms (206) outward once the anchor apparatus (210) and downhole tool (202) have been lowered or raised to a desired position within the wellbore conduit (200).

FIG. 16B depicts the anchor apparatus (204) of FIG. 16A engaged with the wellbore conduit (200). Actuation of the motor or other operator can cause the drive shaft (210) to move the piston (208) in a downhole direction. Contact between the piston (208) and the arms (206) biases the arms (206) in an outward direction to contact the interior surface of the wellbore conduit (200). The engagement between the arms (206) and the wellbore conduit (200) prevents undesired movement of the anchor apparatus (204) and the attached downhole tool (202) responsive to downhole forces, including those generated through actuation of the downhole tool (202). When it is desired to remove the downhole tool (202) and/or the anchor apparatus (204) from the wellbore conduit (200), the drive shaft (210) can be used to retract the piston (208) in an uphole direction, permitting the arms (206) to return to the position shown in FIG. 16A, such as through use of a spring or other biasing member.

Embodiments of the present invention thereby provide anchor apparatuses and methods for anchoring and/or maintaining a position of a tool within a wellbore that provide improved reliability and simplicity over conventionally available devices, can incorporate use of back-up methods of removal, and can further include automatic safety features for preventing attempted retrieval of the anchor apparatus when engaged with the interior surface of a wellbore.

While the present invention has been described with emphasis on certain embodiments, it should be understood that within the scope of the appended claims, the present invention can be practiced other than as specifically described herein.

Claims

1. An anchor apparatus for maintaining a position of a tool within a wellbore, the anchor apparatus comprising:

a tubular body comprising a rod movable within the tubular body and at least one connection for engagement with the tool;

an operator in communication with the rod, whereby actuation of the operator causes movement of said rod between a first position and a second position; and

a plurality of arms pivotally secured to the tubular body, wherein the plurality of arms are pivotally movable between a retracted position and an extended position for engaging an interior surface of the wellbore, wherein the plurality of arms are in operative communication with a biasing member that biases the plurality of arms toward the retracted position, wherein movement of said rod from the first position to the second position causes the plurality of arms to pivot to the extended position, and wherein engagement between the plurality of arms and the interior surface of the wellbore temporarily anchors the tool within the wellbore.

2. The anchor apparatus of claim 1, further comprising a frangible member disposed at an end of the plurality of arms, wherein the frangible member comprises a portion that is provided with a preselected tolerance that exceeds a first force within the wellbore and is less than a second force sufficient to damage the plurality of arms, and wherein the portion of the frangible member breaks upon application of a force greater or equal to the preselected tolerance for enabling removal of the anchor apparatus from the wellbore.

3. The anchor apparatus of claim 1, further comprising a processor in communication with the operator and computer instructions for instructing the processor to receive a command and cause actuation of the operator to move said rod between the first position and the second position responsive to the command.

4. The anchor apparatus of claim 3, wherein the computer instructions further instruct the processor to cause actuation of the operator to move said rod from the second position to the first position to permit the biasing member to pivot the plurality of arms to the retracted position responsive to the command if no command has been received for a preselected length of time.

5. The anchor apparatus of claim 1, wherein the operator comprises a hydraulic power source.

6. The anchor apparatus of claim 3, wherein the operator comprises an electrical motor.

7. The anchor apparatus of claim 6, wherein the electrical motor further comprises electrical connections in communication with the processor, wherein the electrical connections are adapted to transmit current having positive polarity, negative polarity, or combinations thereof, and wherein the computer instructions further instruct the processor to cause actuation of the electrical motor to move said rod from the first position to the second position responsive to current having a first polarity, and to cause actuation of the electrical motor to move said rod from the second position to the first position responsive to current having a second polarity.

8. The anchor apparatus of claim 6, further comprising an addressable switch in communication with the processor, wherein the addressable switch enables actuation of the operator after a preselected code is received by the addressable switch, the processor, or combinations thereof.

9. The anchor apparatus of claim 1, wherein the tool comprises a perforating apparatus, a cutting apparatus, an isolation apparatus, or a logging apparatus.

10. The anchor apparatus of claim 1, wherein the plurality of arms engage the interior surface of the wellbore with a tolerance greater than or equal to a force resulting from actuation of the tool, wherein the tool thereby maintains the position within the wellbore.

11. A method for maintaining a position of a tool within a wellbore, the method comprising the steps of:

engaging the tool with an anchor apparatus and lowering the tool and anchor apparatus to the position within the wellbore;

moving a rod of the anchor apparatus to cause a plurality of arms in operative association with said rod to contact an internal surface of the wellbore;

engaging the plurality of arms with the internal surface of the wellbore, wherein the engagement between the plurality of arms and the internal surface comprises a tolerance;

actuating the tool, producing the well, or combinations thereof, wherein the actuation of the tool, the production of the well, or combinations thereof causes a force, and wherein the tolerance of the engagement between the plurality of arms and the internal surface exceeds the force thereby maintaining the tool in the position within the wellbore.

12. The method of claim 11, further comprising the steps of:

providing a frangible member of the anchor apparatus with a preselected tolerance that exceeds the force caused by actuation of the tool and is less than a second force sufficient to damage the plurality of arms;

breaking the frangible member by applying a force to the frangible member greater or equal to the preselected tolerance, thereby separating at least a portion of the anchor apparatus from the tool; and

removing said at least a portion of the anchor apparatus from the wellbore.

13. The method of claim 11, further comprising the steps of:

disengaging the plurality of arms from the inner surface of the wellbore; and

moving said rod to permit a biasing member of the anchor apparatus in operative association with the plurality of arms to cause the plurality of arms to withdraw from the inner surface of the wellbore.

14. The method of claim 11, wherein the step of moving said rod of the anchor apparatus comprises transmitting a command to a processor in communication with an operator in association with said rod, wherein the processor causes actuation of the operator to cause movement of said rod responsive to the command.

15. The method of claim 13, wherein the step of moving said rod to cause the plurality of arms to contact the interior surface comprises communicating electrical power having a first polarity to cause movement of said rod in a first direction, and wherein the step of moving said rod to permit the biasing member to cause the plurality of arms to withdraw the inner surface comprises communicating electrical power having a second polarity to cause movement of said rod in a second direction.

16. The method of claim 11, further comprising the step of transmitting a preselected code to an addressable switch in communication with said rod, wherein the addressable switch enables actuation of said rod after the preselected code is received.

17. The method of claim 11, wherein the tool comprises a cutting or perforating apparatus, wherein the step of actuating the tool causes pressure from the wellbore, and wherein the tolerance of the engagement between the plurality of arms and the internal surface of the wellbore exceeds the pressure, thereby maintaining the tool in the position with the wellbore.

18. The method of claim 14, further comprising the steps of:

permitting a preselected length of time to pass; and

transmitting a command to the processor, wherein computer instructions in communication with the processor instruct the processor to cause the plurality of arms to withdraw from the inner surface of the wellbore when the command is received after the preselected length of time has passed.

19. An anchor apparatus for maintaining a position of a tool within a wellbore, the anchor apparatus comprising:

a tubular body engaged with the tool, wherein the tubular body comprises a rod movable within the tubular body;

an operator in communication with said rod, whereby actuation of the operator causes movement of said rod between a first position and a second position;

a plurality of arms pivotally secured to the tubular body, wherein the plurality of arms are pivotally movable between a retracted position and an extended position for engaging an interior surface of the wellbore, wherein the plurality of arms are in operative communication with a biasing member that biases the plurality of arms toward the retracted position, wherein movement of said rod from the first position to the second position causes the plurality of arms to pivot to the extended position, and wherein engagement between the plurality of arms and the interior surface of the wellbore temporarily anchors the tool within the wellbore; and

a processor in communication with the operator and computer instructions for instructing the processor to receive a command and cause actuation of the operator to move said rod between the first position and the second position responsive to the command, wherein the computer instructions further instruct the processor to cause actuation of the operator to move said rod from the second position to the first position to permit the biasing member to pivot the plurality of arms to the retracted position responsive to the command if no command has been received for a preselected length of time.

20. The anchor apparatus of claim 19, further comprising a frangible member disposed at an end of the plurality of arms, wherein the frangible member comprises a portion having a preselected tolerance that exceeds a first force within the wellbore and is less than a second force sufficient to damage the plurality of arms, and wherein the portion of the frangible member breaks upon application of a force greater or equal to the preselected tolerance for enabling removal of the anchor apparatus from the wellbore.

21. The anchor apparatus of claim 19, wherein the operator comprises a hydraulic power source.

22. The anchor apparatus of claim 19, wherein the operator comprises an electrical motor.

23. The anchor apparatus of claim 22, wherein the electrical motor further comprises electrical connections in communication with the processor, wherein the electrical connections are adapted to transmit current having positive polarity, negative polarity, or combinations thereof, and wherein the computer instructions further instruct the processor to cause actuation of the electrical motor to move said rod from the first position to the second position responsive to current having a first polarity, and to cause actuation of the electrical motor to move said rod from the second position to the first position responsive to current having a second polarity.

24. The anchor apparatus of claim 19, further comprising an addressable switch in communication with the processor, wherein the addressable switch enables actuation of the power source after a preselected code is received by the addressable switch, the processor, or combinations thereof.

25. The anchor apparatus of claim 19, wherein the tool comprises a perforating apparatus, a cutting apparatus, or an isolation apparatus.

26. The anchor apparatus of claim 19, wherein the plurality of arms engage the interior surface of the wellbore with a tolerance greater than or equal to a force resulting from actuation of the tool, wherein the tool thereby maintains the position within the wellbore.