Abstract:
A method and apparatus for fishing a wellbore with wired drill pipe are provided. Embodiments of the invention advantageously identify objects for removal and signal proper attachment therewith. In an embodiment, a method of fishing with wired drill pipe comprising attaching a fishing apparatus to the end of a wired drill pipe string, extending the wired drill pipe string into a wellbore, monitoring signals received through the wired drill pipe string from one or more sensors coupled to the fishing apparatus, and determining proper coupling of the fishing apparatus with one or more objects intended for removal based on the signals received from the sensors is provided.

Description:
BACKGROUND OF THE INVENTION 
     Description of the Related Art 
     At times, well logging and well forming tools may become detached, stuck, or broken, for example, within a wellbore. In an oilfield, the retrieval of tools, as well as other objects which may enter the wellbores, may need to be conducted from time to time in order to allow well forming and well logging operations to continue efficiently. This retrieval process is often referred to as “fishing” in the wellbore. Additionally, the rigs used for the well logging and well forming operations often contain objects which may fall into the wellbore. These objects may include, for example, articles of clothing and hand tools. 
     Current methods and devices for fishing are incapable of signaling that objects or tools being fished for have been found and properly attached to the retrieval equipment. Tools created for the retrieval of misplaced tools and objects, as well as unwanted debris, simply travel the wellbore in an attempt to gather everything with no indication that all of the objects have been found and collected. Additionally, during fishing operations, logging of the wellbore may be put on hold. Since fishing operations may last for extended periods of time, many opportunities for logging the wellbore may be missed. 
     When a tool, such as a well logging tool, becomes stuck in a wellbore, several events may occur. For example, the cable, such as a wireline, connecting the tool with the surface may be entirely intact and connected to the tool and the surface, the cable may break near the surface and still be connected to the tool, or the cable may break near the tool. In the case when the cable has broken, communication with the tool may no longer be possible and therefore any further measurements taken by the device are lost. 
     Therefore, a method and apparatus for efficiently sensing and gathering objects from a wellbore are needed. Also, a method and apparatus for logging the wellbore while fishing are needed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a partial cross sectional view of an embodiment of a wired drill pipe and a pipe threading apparatus. 
         FIG. 2A  is a partial cross sectional view of an embodiment of a tool overshot with conductive pads. 
         FIG. 2B  is a partial cross sectional view of another embodiment of a tool overshot. 
         FIG. 3  is a partial cross sectional view of an embodiment of a wireline grapple. 
         FIG. 4  is a partial cross sectional view of an embodiment of a debris removal mechanism. 
         FIG. 5  is a partial cross sectional view of an embodiment of a magnetic debris removal mechanism. 
         FIG. 6  illustrates an embodiment of a logging while fishing tool. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present inventions generally relate to apparatus and methods for retrieving (“fishing”) tools or other unwanted items from an oilfield wellbore using wired drill pipe having tools connected thereto. 
       FIG. 1  shows an embodiment of a drill pipe threading apparatus  100  which may be used to thread a cable  101 , such as a wireline, a slickline or other cable providing data and/or power communication, through a drill string, such as the drill pipe sections  106 A and  106 B. In an embodiment, the drill pipe sections  106 A and  106 B may be wired drill pipe. Wired drill pipe in general may be a drill pipe which has an internal communication channel connected to communication elements in the box and pin ends of the drill pipe. The communication element, such as an inductive or flux coupler, of each pipe may communicatively couple with the communication elements of other wired drill pipes to create a communication channel along a whole string of wired drill pipe. The communication elements may also be used to communicatively couple with surface components and downhole tools. Examples of wired drill pipe that may be used in the present disclosure are described in detail in U.S. Pat. Nos. 6,641,434 and 6,866,306 to Boyle et al. and U.S. Pat. No. 7,413,021 to Madhavan et al. and U.S. Patent App. Pub. No. 2009/0166087 to Braden et al., assigned to the assignee of the present application and incorporated by reference in their entireties. 
     The drill pipe threading apparatus  100  may generally consist of a spearhead sub  102 , a cable  103 , and a spearhead overshot  105 . The plurality of wired drill pipe sections  106 A and  106 B may be coupled together to form a wired drill pipe string which may have a fishing apparatus, for example a tool overshot  201  shown in  FIG. 2A , coupled to the end for retrieving a cable conveyed tool string  200 . The tool string  200  shown in  FIG. 2A  may be lost or stuck, such as being caught in a crack, wedged to the wellbore wall by debris, stuck due to a pressure differential or may be stuck or otherwise irretrievable for any other reason that will be appreciated by those having ordinary skill in the art. The threading apparatus  100  may be useful when the cable  101  is still connected to both the surface and the stuck tool or the cable  101  has a sufficient length to be retrieved by a cable fishing apparatus, for example a wireline grapple  300  shown in  FIG. 3 . Threading of the wired drill pipe string may assist in guiding the fishing tool to the tool string  200  which may be lost downhole. The cable  101  may be coupled to the spearhead sub  102  for facilitating threading of the cable  101  through the wired drill pipe sections  106 A and  106 B. The cable  103  may have one end connected to a pipe elevator of a drill rig (not shown) and the other end may be coupled to the tool overshot  201 . 
     The spearhead overshot  105  may be fed through the wired drill pipe section  106 A. A previously threaded wired drill pipe section  106 B may be wedged in place above the wellbore  109  using slips  107  or other device to clamp the drill string, while a spearhead sub  102  may be held in place with a clamp  108 , such as a c-plate. The spearhead overshot  105  may be coupled with the spearhead sub  102 . The clamp  108  may be removed and the spearhead overshot  105  may hold the spearhead sub  102  while the wired drill pipe section  106 A may be coupled to the previously threaded wired drill pipe section  106 B. The slips  107  may be loosened and the newly threaded wired drill pipe section  106 A may be lowered into the wellbore  109 . The wired drill pipe section  106 A may then be wedged in place using the slips  107 . The spearhead sub  102  may be pulled through the wired drill pipe section  106 A by pulling up on the cable  103  with the pipe elevator (not shown). The spearhead sub  102  may be brought to the end of the wired drill pipe section  106 A and held in place with the use of the clamp  108 . The spearhead overshot  105  may then decouple from the spearhead sub  102 . The steps described above may be repeated until a string of wired drill pipe sections  106 A,  106 B is created. The string of wired drill pipe sections  106 A,  106 B may be guided by the cable  101  to the stuck tool string  200 . 
       FIG. 2A  illustrates embodiments of a tool overshot  201  having conductive pads  202  to sense connection with a tool string  200  which may be lost or stuck in a wellbore  212 . The tool string  200  may generally include one or more tools  204  which may be coupled in an assembly, one or more centralizers  205  positioned along the tool string  200 , a spear section  210 , and one or more conductive contacts  203 . The one or more tools  204  may measure a property of the wellbore  212 , a formation about the wellbore  212 , and/or the drill string. In an embodiment, the tools  204  may be well logging tools, such as for example formation evaluation tools, formation sampling tools, and/or well completion tools, such as for example perforating tools. The formation evaluation tools may include, but are not limited to, induction resistivity instruments, gamma ray sensors, formation fluid sampling devices (which may include fluid pressure sensors). The one or more centralizers  205  may be adapted to provide a standoff distance from the wellbore wall and the tool string  200 . The spear section  210  may be coupled to the end of the cable  101  and the top of the tool string  200 . The conductive contacts  203  may be a conductive material linearly spaced and wrapped around the spear section  210 . The conductive contacts  203  may be communicatively coupled with the one or more tools  204 , the cable  101 , or both, and adapted to communicatively couple with the conductive pads  202  of the tool overshot  201 . 
     The cable  101  may be fed through a number of wired drill pipes  206 , as described above, and the resulting wired drill pipe string may be coupled with the tool overshot  201 . The tool overshot  201  comprises a conductive grapple assembly including a body  207 , a head section  208 , the conductive pads  202 , and a grapple mechanism  209 . Examples of the grapple mechanism are shown and described in U.S. Pat. Nos. 2,970,859; 3,191,981; 2,745,693; and 4,061,389; 4,877,085, which are incorporated by reference in their entirety. In an embodiment, the grapple mechanism  209  may be sized and shaped like a loosely wound spring that may grab the tool  204  of the tool string  200  that is connected to the spear section  210 . The grapple mechanism  209  may have an internal diameter that is smaller than an external diameter of the tool  204  when in an uncompressed state. In an embodiment, as the tool string  200  is inserted into the tool overshot  201 , the grapple mechanism  209  may be compressed as it is forced against an upper surface of the tool  204 . In another embodiment, an actuator (not shown) may be coupled with grapple mechanism  209  to compress the grapple mechanism  209 . During this compression, the internal diameter of the grapple mechanism  209  may increase until the internal diameter of the grapple mechanism  209  is the same or larger than the external diameter of the tool  204 . The tool string  200  may be more easily inserted into tool overshot  201  by compressing the grapple mechanism  209  with the actuator, to increase the internal diameter of the grapple mechanism  209 , prior to insertion of the tool string  200  into the tool overshot  201 . The actuator may be released once the tool string  200  is inserted to allow the grapple mechanism  209  to grapple the tool  204 . Friction between the grapple mechanism  209  and the tool  204  retains the tool string  200  within the tool overshot  201 . The friction between the tool  204  and the grapple mechanism  209  increases as the tool string  200  pulls against the grapple mechanism  209  during removal of the tool string  200  from its stuck position. As the tool string  200  pulls against the grapple mechanism  209 , tension is created in the grapple mechanism  209  which forces the grapple mechanism  209  to try and lengthen and consequently decrease in diameter. However, since the grapple mechanism  209  is wrapped around the tool  204  the grapple mechanism  209  cannot decrease in diameter and therefore extra pressure is applied to the tool  204  instead. 
     The body  207  of the tool overshot  201  may be shaped to match a contour of the spear section  210  to ensure proper alignment of the tool string  200  with the tool overshot  201 . The spear section  210  may be further adapted to assist in guiding the tool string  200  into the tool overshot  201 . A tapering upper end of the spear section  210  may contact an inner portion of the head section  208 , thereby urging the spear section  210  toward the center of the tool overshot  201 . The spear section  210  may then enter the body  207 . The conductive pads  202  may be linearly spaced along the body  207  at intervals corresponding with the conductive contacts  203 . When the spear section  210  is fully inserted into the tool overshot  201  the conductive pads  202  and conductive contacts  203  are aligned. The conductive pads  202  may be communicatively coupled with the communication channel of the wired drill pipe string. The tool overshot  201  may be lowered until a receiver (not shown) connected to the top of the wired drill pipe string, consisting of the wired drill pipe sections  206 , senses a connection between the conductive pads  202  and one or more conductive contacts  203 . In an embodiment, communicating and receiving signals through the wired drill pipes  206  with the tool string  200  may indicate proper connection with the tool string  200 . The tool string  200  may be removed from the wellbore  212  once coupled with the tool overshot  201 . 
       FIG. 2B  illustrates an embodiment of the tool overshot  201  being used to locate the tool string  200  when the cable  101  has been broken. In such a situation, the cable may be too short to be retrieved and threaded as shown in  FIG. 1 . Threading of the cable  101  through the wired drill pipes  206  allows the tool overshot  201  to be guided to the tool string  200 . If threading of the cable  101  is not possible then sensors coupled to the tool overshot  201  and wired drill pipes  206  may need to be relied upon for efficiently locating the tool sting  200 . Therefore, in order to efficiently fish for the tool string  200 , the conductive pads  202  of the tool overshot  201  may be used to verify proper insertion of the tool string  200  into the tool overshot  201  as described above for  FIG. 2A . In another embodiment, verifying insertion of the tool string  200  into the tool overshot  201  may be accomplished by sensing connection between a corresponding number of the conductive pads  202  and conductive contacts  203 . For example, if there are six conductive pads  202  and six corresponding conductive contacts  203 , verifying complete insertion of the tool string  200  into the tool overshot  201  may be established by sensing six connections between the conductive pads  202  and conductive contacts  203 . 
     In another embodiment, a fluid pressure sensor  211  may be coupled to the tool overshot  201 . The fluid pressure sensor  211  may be used to measure the pressure of fluid within the tool overshot  201 . An increase in pressure sensed by the fluid pressure sensor may indicate proper insertion of the tool string  200  into the tool overshot  201 . In another embodiment, a strain gauge (not shown) may be coupled with the grapple mechanism  209  of the tool overshot  201 . The strain gauge may be used to sense connection with the tool string  200 . A sufficient increase in strain shown by the strain gauge during extraction of the tool string  200  may indicate that the tool string  200  has been properly coupled with the tool overshot  201  and is being carried out of the wellbore  212 . In another embodiment, a sonar camera may be used to determine coupling of the tool overshot  201  with tool string  200 . 
     The process of verifying insertion of the tool string  200  into the tool overshot  201  described above may decrease the time spent retrieving the stuck tool string  200 . In an embodiment, the tool string  200  may contain well logging tools. Signals cannot be communicated from the tool string  200  to the surface through the broken cable  101 , and it may therefore be beneficial to transmit signals from the tool string  200  through the wired drill pipes  206  instead. Signals from the tool string  200  may be transmitted from the conductive contacts  203  to the conductive pads  202 . The signals may then be transmitted up the wired drill pipe string to a surface component. In this embodiment, well logging measurements may be obtained by the tool string  200 , and transmitted to the surface to be recorded, while the tool string  200  is being removed from the wellbore  212 . This may be beneficial since the downtime in measurement acquisition will be reduced. Additionally, a diagnosis of the event which caused the tool string  200  to become stuck downhole may be determined from measurements taken by the tool string  200 , and possible reasons for the tool string  200  becoming stuck may be discovered. Such measurements may include detecting wellbore irregularities, such as wash-out, mud-cake quality or mud invasion of the formation, wellbore and formation pressure, and wellbore diameter changes, among others. 
       FIG. 3  illustrates a partial cross section of an embodiment of a wireline grapple  300  which may be used to retrieve a cable  101  connected to a stuck tool string  200 . As shown, the cable  101  has broken with sufficient length to be retrieved. The wireline grapple  300  may be extended down a wellbore  310  on a wired drill pipe string  301  in order to retrieve the cable  101 . The wireline grapple  300  may include a grapple mechanism  302 , a motor  303  to drive and operate the grapple mechanism  302 , and a relay  304  which may be used to operate the motor and one or more sensors  305  coupled to the wireline grapple  300 . The relay  304  may be communicatively coupled with the wired drill pipe string  301  in order to send and receive signals with a surface component. In an embodiment, the one or more sensors  305  may include a conductive sensor, coupled with the wireline grapple  300 , to sense when a conductive material, such as the broken cable  101 , is in contact with the grapple mechanism  302 . Once the conductive sensor senses contact with the cable  101 , a signal may be sent to the relay  304  which may activate the motor  303 , thereby closing the grapple mechanism  302 . In another embodiment, the grapple mechanism  302  may be closed automatically by the relay  304  when conductive contact is sensed. The one or more sensors  305  may also include a pressure sensor, coupled with the wireline grapple  300 , which may indicate when sufficient grappling pressure is created between the grapple mechanism  302  and the cable  101  to lift the cable  101  back to the surface. The wireline grapple  300  may additionally be rotated in order to wrap a section of the cable  101  around the grapple mechanism  302 , which may increase the grip of the grapple mechanism  302  on the cable  101 . 
       FIG. 4  illustrates a partial cross section of an embodiment of a debris removal mechanism  400  coupled to a wired drill pipe string  401 . The debris removal mechanism  400 , also referred to as a “junk basket”, may include an outer wall  402  which may define an internal volume  409 . The perimeter of the outer wall  402  may be polygonal or circular in shape. The debris removal mechanism  400  may further include one or more doors  403 , one or more door actuators  407 , a relay  404 , and a sensor  405 . In an embodiment, the door actuators  407  may selectively open or close the one or more doors  403  when a signal is received from the relay  404 . The door actuators  407  may be one of a hydraulic cylinder, linear actuator, drive screw, or similar device. The relay  404  is communicatively coupled with the wired drill pipe string  401 . The relay  404  may also be adapted to send and receive signals through the wired drill pipe string  401  with the surface. The relay  404  may be further adapted to interpret received signals which may indicate a request to open the one or more doors  403 , for example. The sensor  405  may be, for example, a pulse echo type sensor, which may include a sonic pulse source and an echo detection unit. An operator or surface component may use the signals sent through the wired drill pipe string  401  by the sensor  405  to locate debris  406  within the wellbore  410 . A variation from a baseline value of the signal sent by the sensor  405  may indicate that a piece of debris  406 , such as for example articles of clothing, hand tools, and other objects from the rig running the well operations, has been located. In an embodiment, a characteristic signal of the sensor  405  may be associated with the debris  406 . The characteristic signal, when observed, may indicate that the debris  406  has been located. Once the debris  406  has been found, the doors  403  may be opened to capture the debris  406 . An additional sensor  408  coupled within the debris removal mechanism  400  may be used to indicate that the debris  406  has been captured within the internal volume  409 . The doors  403  may then be closed in order to retain the debris  406  for removal. 
       FIG. 5  illustrates a partial cross section of an embodiment of a magnetic debris removal mechanism  500 . The magnetic debris removal mechanism  500  may include a magnetic removal tool, such as an electro-magnet  502 , a relay  503 , and a sensor  504 . The magnetic debris removal mechanism  500  may be coupled to a wired drill pipe string  501  for conveyance of the magnetic debris removal mechanism  500  through a wellbore  510 . The relay  503  may be communicatively coupled with the wired drill pipe string  501  in order to send and receive signals with a surface component. In an embodiment, the sensor  504  may be a magnetic sensor which senses the presence of material that is attracted to magnetic fields. The magnetic debris removal mechanism  500  may be conveyed through the wellbore  510  with the electro-magnet  502  turned off until the sensor  504  senses the presence of debris  505 . In an embodiment, the debris  505  may be detected and then the electro-magnet  502  may be switched on to capture the debris  505  and bring it up to the surface. The debris  505  may be any material that is attracted to magnetic fields, such as, for example, tool fragments, broken wireline, and hand tools that have fallen into the wellbore  510 , among others. The relay  503  may be further adapted to interpret received signals which may indicate a request to turn on or off the electro-magnet  502 . 
     The devices and methods described above may be further enhanced with the use of a logging sub  603 , as shown in  FIG. 6 . The logging sub  603  may consist of one or more logging/measurement instruments  605 , formed into an assembly. Each instrument  605  may have a bore  606  formed therethrough. The bore  606  may provide a path for fluid to pass through. One end of the logging sub  603  may be coupled to a wired drill pipe string  601 , and a fishing apparatus  604  may be coupled below the logging sub  603 . The wired drill pipe string  601  may be coupled to a rig  600  for conveyance of the wired drill pipe string  601  into a wellbore  607 . The wired drill pipe string  601  may consist of a number of wired drill pipe sections  602  coupled end to end. The logging sub  603  may be adapted to log characteristics of the wellbore  607  or formations about the wellbore  607 . The logging sub  603  may be further adapted to take measurements during fishing operations by passing signals through the wired drill pipe string  601  to a surface component (not shown), such as a processor or data storage device. As shown, a tool string  608  may be stuck against a wall of the wellbore  607  by debris  610 . The tool string  608  may be connected to a cable  609  for guiding the fishing apparatus  604  to the tool string  608 . In an embodiment, the fishing apparatus may be the tool overshot  201  such as shown and described in reference to  FIGS. 2A and 2B . The logging sub  603  may take measurements while the wired drill pipe string  601  is extended into the wellbore  607  so that the fishing apparatus  604  may retrieve the tool string  608 . 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.