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.

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.