Patent Publication Number: US-2019169981-A1

Title: Apparatus and method for monitoring a blocking body within an oil-well structure

Description:
TECHNICAL FIELD 
     The present disclosure relates to oil and/or gas wells. In particular the present disclosure relates to a method and an apparatus for detecting and/or monitoring an object within a well structure. 
     BACKGROUND 
     An oil and/or gas well may be formed by an outer casing located within a wellbore. The outer casing may optionally be secured within the wellbore by cement. The well may then include a tool or production string therein for working or producing from the well. During various procedures within the well, the well structure may utilize blocking bodies, such as balls, to engage and activate internal valves or to seal off ball-seats for isolating certain intervals or zones within the well. Isolating intervals or zones of the well is useful during hydraulic fracturing (fracking) operations and the like. One disadvantage of such blocking bodies is that the equipment utilized to introduce the blocking bodies by injecting, dropping or launching the blocking bodies into the well may be unreliable. This may cause uncertainty as to the number of the blocking bodies that are introduced and/or the timing of such introductions of the blocking body into the well. Ultimately, the user may not be certain as to the number or identification of which valves or ball seats within the well are activated by the introduced blocking bodies. 
     A known method to determine if a blocking body has been dropped is to watch the pressure within the well for a spike. The pressure spike may indicate that the blocking body has engaged in a valve within the well. However, such a method relies on indirect measurements of a blocking body&#39;s location and such a method may not provide a definitive answer as to whether a dropped blocking-body has been introduced into a well and engaged a valve within the well. Such a method also does not provide a definitive answer as to any particular valve that the blocking body may engaged. Such a method is also susceptible to operator error for example, if a brief pressure spike is missed then that may result in a false-negative when a ball has been introduced into the well. 
     SUMMARY 
     Some embodiments of the present disclosure relate to a system for monitoring blocking bodies that are introduced into a well. The system comprises a detection tool and at least one blocking body that is capable of generating a detectable signal. The detectable signal can be detected by the detection tool when the blocking body passes through a predetermined portion of the well. When the detection tool detects the detectable signal, the detecting tool generates an output signal that indicates that a detection event has occurred and the blocking body has approached, moved through and moved away from predetermined portion of the well. 
     In some embodiments of the present disclosure the detection tool utilizes one or more sensors for detecting the detectable signal. For example, if the detectable signal is a perturbation of a magnetic field, then the detection tool utilizes one or more magnetic sensors for detecting perturbations in the magnetic field. In other examples, the detectable signal may be another form of electromagnetic signals, such as a radio signal. The radio signal may be generated at a specific frequency and the one or more sensors of the detection tool are radio-frequency sensors. In some embodiments of the present disclosure the at least one blocking body comprises a radio frequency identification (RFID) member and when the RFID member approaches, moves through or moves away from the detecting tool, the one or more radio-frequency sensors can generate an output signal that indicates a detection event. 
     Some embodiments of the present disclosure relate to a detection system for detecting when a blocking body has passed through a location within a well. The detection system comprises a blocking body and a detection tool. The blocking body can be introduced into the well and is operatively configured to produce a detectable signal. The detection tool is configured to detect the detectable signal and to generate an output signal that indicates a detectable event. 
     In some embodiments of the present disclosure at least a portion of the blocking body comprises a magnetic material. In these embodiments, the detection tool also generates a magnetic field and comprises at least one sensor that can detect perturbations in the magnetic field that are caused by the blocking body approaching, moving through or moving away from the detection tool. 
     In some embodiments of the present disclosure, the blocking body comprises a radio frequency identification (RFID) tag that generates a radio signal and the detection tool comprises at least one sensor that can detect the radio signal. 
     Further embodiments of the present disclosure relate to a method for detecting a blocking body within a well. The method comprises the steps of configuring the blocking body to generate a detectable signal; configuring at least a portion of the well to detect the detectable signal; and creating an output signal that identifies when the detectable signal is detected. 
     In some embodiments of the present disclosure the detectable signal is a perturbation of a magnetic field. In some embodiments of the present disclosure the detectable signal is generated by an RFID tag and the at least a portion of the well can detect a radio signal generated by the RFID tag. 
     Without being bound by any particular theory, embodiments of the present disclosure allow a user to directly detect when a blocking body has passed through a predetermined portion of a well and in some embodiments when blocking bodies have passed through the predetermined portion of the well. This allows the user to know how many blocking bodies have been introduced into a well by relying on direct measurements of blocking bodies relative to the detection tool. 
     According to one aspect, there is disclosed a detection system for detecting when a blocking body has passed through a location within a well. The detection system comprises: (a) a blocking body that is introducible into the well and is operatively configured to produce a detectable signal; and (b) a detection tool that is configured to detect the detectable signal and to generate an output signal that indicates a detectable event. 
     In some embodiments, at last a portion of the blocking body comprises a magnetic material and the detection tool generates a magnetic field and comprises at least one sensor that can detect perturbations in the magnetic field caused by the blocking body approaching, moving through or moving away from the detection tool. 
     In some embodiments, the detection tool comprises a tubular body and two or more clamp pieces removably coupled about the tubular body, and wherein the two or more clamp pieces generate said magnetic field. 
     In some embodiments, the at least one sensor is coupled to the two or more clamp pieces. 
     In some embodiments, the detection tool further comprises at least one actuator coupled to the two or more clamp pieces for configuring the two or more clamp pieces to be away from the tubular body in an open condition or to be about the tubular body in a closed condition. 
     In some embodiments, the blocking body comprises a radio frequency identification (RFID) tag that generates a radio signal and the detection tool comprises at least one sensor that can detect the radio signal. 
     In some embodiments, the detection system further comprises a display for receiving and displaying the output signal from the detection tool. 
     According to one aspect, there is provided a method for detecting a blocking body within a well. The method comprises steps of: (a) configuring the blocking body to generate a detectable signal; (b) configuring at least a portion of the well to detect the detectable signal; and (c) creating an output signal that identifies when the detectable signal is detected. 
     In some embodiments, the detectable signal is a perturbation of a magnetic field. 
     In some embodiments, the detectable signal is generated by an RFID tag and the at least a portion of the well can detect a radio signal generated by the RFID tag. 
     In some embodiments, the RFID tag comprises a unique identifier, and wherein the output signal comprises said unique identifier. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In drawings which illustrate embodiments of the present disclosure wherein similar characters of reference denote corresponding parts in each view; 
         FIG. 1  is a cross-sectional view of the top end of a wellbore having an outer casing and a production string located therein with one embodiment of a detection tool according to the present disclosure; 
         FIG. 2  is an isometric view of one embodiment of a detection tool according to the present disclosure; 
         FIG. 3  is a side-elevation, mid-line cross-sectional view of the detection tool shown in  FIG. 2 ; 
         FIG. 4  is a top-plan, cross-sectional view of the apparatus of  FIG. 2 . 
         FIG. 5  is an illustration of one example of a display output showing voltage produced over time by a sensor of the apparatus of  FIG. 2  as a blocking body according to the present disclosure passes therepast; 
         FIG. 6  is an isometric view of another detection tool according to embodiments of the present disclosure; 
         FIG. 7  is a side elevation view of another detection tool according to embodiments of the present disclosure; 
         FIG. 8  is a top-plan, cross-sectional view of a blocking body in use with a detection tool according to embodiments of the present disclosure; 
         FIG. 9  is a cross-sectional view of a sensor assembly according to embodiments of the present disclosure; 
         FIG. 10  shows mid-line, cross-sectional views of a blocking body, wherein in  FIG. 10A  the blocking body comprises a shell, and in  FIG. 10B  the blocking body comprises a core; 
         FIG. 11  is a side-elevation, mid-line cross-sectional view of a detection tool, according to some alternative embodiments of the present disclosure; 
         FIG. 12  is a side-elevation, mid-line cross-sectional view of a detection tool having a detection clamp, according to yet some alternative embodiments of the present disclosure; 
         FIG. 13  is a side-elevation, mid-line cross-sectional view of a detection tool having a detection clamp, according to still some alternative embodiments of the present disclosure; 
         FIG. 14  is an isometric view of a detection tool having a detection clamp having a detection clamp, according to some alternative embodiments of the present disclosure; 
         FIG. 15  is an isometric view of a detection tool having a detection clamp, according to yet some alternative embodiments of the present disclosure, wherein detection clamp is configured in an open condition; and 
         FIG. 16  is an isometric view of the detection tool shown in  FIG. 15 , wherein detection clamp is configured in a closed condition. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a non-limiting example of a well assembly  10  located within a well bore  8  of a geological formation  6 . While the geological formation  6  is shown at the surface where the well assembly  10  is positioned, it is understood that the geological formation  6  may be continuous with the surface at the position of the well assembly  10 , or not. The well assembly  10  includes a well casing  12  having a top flange  14  which is securable to a pipe ram  16  or any other desired components that are employed at well sites. It will be appreciated that a detection tool  20  according to the present disclosure may be located at any location within the well assembly  10 , such as, by way of non-limiting example, within or adjacent a riser, adjacent a frack-ball launcher (not shown), adjacent a blowout preventer (BOP) or at any other position within the well apparatus  10 . It will be appreciated by those skilled in the art that only a single pipe ram  16  as an example of a well assembly  10  component is illustrated in  FIG. 1  for the sake of clarity. It will be appreciated that many well assemblies  10  can include more than one of such component and other components. As illustrated in  FIG. 1 , the well assembly  10  includes the detection tool  20  for detecting a signal generated by a blocking body  15  (shown in  FIG. 8 ) with one or more further components  18  of the well assembly  10  located thereabove. A blocking body  15  may pass through the detection device  20  by being introduced into, for example dropped or actively pushed through, a portion of the well assembly  10  above the detection tool  20 . 
     In some embodiments of the present disclosure, the detection tool  20  is substantially the same as the device described in U.S. Pat. No. 9,097,813 , the entire disclosure of which is incorporated herein by reference. In these embodiments, the detection tool  20  is configured to detect a perturbation in a magnetic field that is caused by one or more blocking bodies  15  approaching, passing through and moving away from the detection tool  20 . 
       FIG. 1  shows the well assembly  10  as including a production or tubing string  115  that is located within the well assembly  10 . The string  115  also includes one more regions of a larger outer diameter  117 , for example a tool joint, a downhole tool or otherwise. It will be appreciated by one skilled in the art that the one or more blocking bodies  15  may be introduced into the tubing string  115  above the detection tool  20  and the one or more blocking bodies  15  can travel down the tubing string  115  to engage a downhole element (not shown). Examples of downhole elements include but are not limited to: sliding sleeve, seated ball valves and the like. Alternatively, the tubing string  115  may not be present as a component of the well assembly  10  and the one or more blocking bodies  15  may be introduced into the well assembly  10  above the detection tool  20  and the one or more blocking bodies  15  may travel down a portion of the well bore  8  to engage a downhole element. 
     In some embodiments of the present disclosure, the detection device  20  is configured to detect the signal generated by the blocking body  15  and the detection device  20  is also configured to generate an output signal that is communicated to a computer  88  and/or display  89 . The computer  88  and/or display  89  indicate to a user that the blocking body  15  is approaching, moving through or moving away from the detection tool  20  to permit the user to determine when a blocking body  15  has passed through the detection tool  20  and into the well bore  8  below. 
     With reference to  FIG. 2 , the detection tool  20  comprises a body  22  having at least one magnetic stack  70  and at least one sensor stack  80  extending away from the body  22 . The body  22  comprises at least one tubular or ring-shaped body  22  section.  FIG. 2  shows an upper section or flange  28  and a lower section or flange  30 . Each body  22  section  28 ,  30  has inner and outer surfaces,  24  and  26 , respectively and extending between top and bottom surfaces,  27  and  29 , respectively (shown only on the upper body  22  section  28 ). As illustrated in  FIG. 2 , the inner and outer surfaces  24  and  26  are substantially cylindrical about a central axis  32  of the body  22 . The inner surface  24  defines a central passage  34  extending therethrough which may be sized and shaped to correspond to the interior of the casing  12 . As illustrated in  FIG. 2  and  FIG. 3 , the top and bottom surfaces are substantially planar along a plane normal to the axis  32  and may optionally include a seal groove  36  extending annularly therearound for receiving a seal as are commonly known in the art. 
     The body  22  includes at least one bolt hole  35  that extends therethrough between the top and bottom surfaces  27  and  29  along an axis that is substantially parallel to the central axis  32 . The bolt holes  35  are utilized to pass fasteners, such as bolts  38  as illustrated in  FIG. 1  therethrough to secure the body  22  inline to the other components of the well assembly  10  according to known methods in the art. 
     The body  22  includes at least one magnetic stack  70  and at least one sensor stack  80  as will be more fully described below. Optionally each of the stacks  70  and  80  may be contained within a housing, such as, by way of non-limiting example, a sleeve  40  extending from the outer surface of the body  22  (as shown in  FIG. 2  and  FIG. 3 ) between the upper and lower bodies  28 ,  30 . 
     The body  22  may have any distance between the upper and lower sections  28 ,  30  as is necessary to accommodate the stacks  70 ,  80 . By way of non-limiting example the body  22  may have a distance between the upper and lower sections  28 ,  30  of between 3.5 and 24 inches (89 and 610 mm) with a thickness of approximately 4 inches (102 mm) having been found to be particularly useful. Additionally, the body  22  will be selected to have an inner diameter of the inner surface  24  to correspond to the inner passage of the casing  12 . In practice it has been found that an outer diameter of between 4 and 12 inches (102 and 305 mm) larger than the inner diameter has been useful. The body  22  may be formed of a non-magnetic material, such as, by way of non-limiting example a nickel-chromium based alloy, such as Inconel® manufactured by Special Metals Corporation. It will also be appreciated that other materials may be useful as well, such as, by way of non-limiting example duplex and super duplex stainless steels provided they do not interfere with the sensor operation as described below. 
     Optionally, the body  22  may be formed as a hub clamp wherein the upper and lower sections  28 ,  30  comprise clamping bodies adapted to clamp adjacent pipes as illustrated in  FIG. 6  and as are commonly known. In operation, the top and bottom flanges  28  and  30  may be secured to such additional structures through the use of bolts or the like as is commonly known. Optionally, the body  22  may be formed as a hub clamp wherein the top and bottom flanges  28  and  30  may comprise clamping bodies adapted to clamp adjacent pipes as illustrated in  FIG. 6 . 
     As set out above, the body  22  may optionally include a plurality of sleeves  40  that are adapted to contain and protect the stacks  70  and  80  that extend radially from the outer surface  26  of the body  22 . As illustrated in  FIG. 2  through  FIG. 4 , the sleeves  40  may extend radially from the body  22 . It will be appreciated that the stacks  70  and  80  may also extend from the tubular body  22  without such sleeves  40  therearound. As illustrated in  FIG. 3 , each of the sleeves  40  may be located at a position along the tubular body  22  so as to form a common plane  42  perpendicular to the central axis  32  of the apparatus. As illustrated in  FIG. 7 , the magnetic and sensor stacks  70  and  80  may also be arranged along more than one plane  42   a,    42   b  and  42   c  so as to form sensor locations enabling a user to track the progress of blocking bodies  15  through the detection tool  20 . 
     The sleeves  40  comprise tubular members extending between first and second ends,  46  and  48 , respectively, and having inner and outer surfaces,  50  and  52 , respectively. The sleeves  40  may be formed of a substantially ferromagnetic material, such as steel so as to conduct magnetic flux as will be more fully described below. The sleeves  40  are selected to have a sufficient inner surface diameter sufficient to accommodate a magnetic stack  70  or a sensor stack  80  therein as more fully described below. By way of non-limiting example it has been found that a diameter of the inner surface of between 0.5 and 6 inches (13 and 152 mm) has been useful. The sleeve  40  may also have a length sufficient to receive the sensor and magnet stacks therein, such as by way of non-limiting example, between 0.5 and 6 inches (13 and 152 mm). Additionally, it will be appreciated that where other housing types are utilized, such housings may be formed of any suitable size to contain and protect the stacks  70 ,  80  from impacts or the like. 
     Turning now to the non-limiting examples of  FIG. 3  and  FIG. 4 , the sleeves  40  are arranged around the body  22  along a common plane  42 . The common plane  42  is perpendicular to the central axis  32  and may be located at any height along the body  22  such as by way of non-limiting example, midpoint therealong as illustrated in  FIG. 3 . As illustrated in  FIG. 4 , the sleeves  40  may be arranged around the tubular body  22  at regular intervals; however this may not be required. As illustrated herein, sleeves  40  are secured to the outer surface  26  of the tubular body  22  by using suitable means such as welding, gluing (e.g., using epoxy), and/or the like. The sleeves  40  contain therein at least one magnetic stack  70  and at least one sensor stack  80  wherein the magnetic stack  70  generates a magnetic field within the interior of the central passage  34  and the sensor stack  80  measures changes in this magnetic field in response to a blocking body  15  passing therethrough. In particular, the magnetic stacks  70  and sensor stacks  80  may be alternated around the tubular body  22  and it will therefore be appreciated that an even number of sleeves will be required. It will also be appreciated that other arrangements of magnetic and sensor stacks may be useful as well. 
     The magnetic stack  70  comprises at least one magnet  60  that is sized to be located within the sleeve  40 . The magnets  60  are selected to generate strong magnetic fields. In particular, it has been found that rare earth magnets, such as, by way of non-limiting example, neodymium, samarium-cobalt or electromagnets. Optionally, the magnets  60  may also be nickel plated or otherwise coated for corrosion resistance. 
     The sensor stack  80  comprises a sensor  82  adapted to provide an output signal in response to the magnetic field in their proximity. By way of non-limiting example, the sensors  82  may comprise magnetic sensors, such as hall-effect sensors although it will be appreciated that other sensor types may be utilized as well. In particular it has been found that a Hall effects sensor, such as a model SS496A1sensor manufactured by Honeywell® has been particularly useful although it will be appreciated that other sensors will also be suitable. The sensors  82  are inserted into the sleeves  40  to be proximate to the first end  46  thereof and are retained within the sleeves  40  by any suitable means, such as, by way of non-limiting example, adhesives, threading, fasteners or the like. The sensors  82  may each include an output wire  86  that extends therefrom as illustrated in  FIG. 1 . The output wire  86  is wired or otherwise connected to a computer  88  which optionally outputs to a display  89  and is therefore operable to provide an output signal that indicates whether a detection event has occurred. 
     The sensor stack  80  may also optionally include a magnet  84  located at the second end  48  of the sleeve  40 . The magnets  84  are selected to have strong magnetic fields. In particular, it has been found that rare earth magnets, such as, by way of non-limiting example, neodymium, samarium-cobalt or electromagnets. Optionally, the magnets  84  may also be nickel plated or otherwise coated for corrosion resistance. The magnets  84  are located at the second ends  48  of the sleeves  40  and retained in place by any suitable means, such as, by way of non-limiting example, adhesives, threading, fasteners or the like. 
     With reference to  FIG. 5 , the output  100  may display the voltage signal outputted by the one or more sensors  82  against time. During a first time period, the voltage signal will be at a first level, generally indicated at  102 , while no blocking body  15  is near to passing through the detection tool  20 . As the blocking body  15  approaches the detection tool  20 , the voltage output of the sensors  82  will be increased, generally indicated by the slope between  102  and  104 , due to the detection tool  20  detecting the detectable signal from the blocking body  15  within the central passage  34 . After the blocking body  15  passes through the detection tool  20 , the voltage will return to a lower level  106 . In such a manner, the display  100  will indicate to an operator when the blocking body  15  has approached and passed through the detection tool  20 . 
     In some embodiments of the present disclosure, the sensors  82  may be calibrated prior to operation by locating a magnetic body of known size and position within the central passage  34  and adjusting the readout for each sensor  82   a,    82   b  and  82   c  according to known methods. Optionally, a radio frequency emitter device may also be used to calibrate the radio frequency sensors within the detection tool  20 . As illustrated in  FIG. 8 , a single set of 3 sensors  82  may be utilized to provide a location of the blocking body  15  as it passes through the detection tool  20 . It will be appreciated, that additional sets of 3 or more sensors may also be provided to provide an additional measure of the position of the blocking body  15 . 
       FIG. 9  provides a detailed cross-sectional view of one embodiment of the magnetic stack  70 . The magnetic stack  70  may be located within a sleeve  40  which also includes an actuator  120  and an actuator shaft  122  extending from the actuator  120  to the magnetic stack  70 . In operation, the actuator  120  may extend or retract the magnetic stack  70  into and out of engagement with the outer surface  26  of the tubular body  22 . In the retracted position, the magnetic field produced by the magnetic stack  70  will be reduced thereby permitting any ferromagnetic particles that may be attracted thereto to be released from the interior of the central passage. 
     Turning now to  FIG. 10A  and  FIG. 10B , the blocking body  15  is shown as a ball; however, the person skilled in the art will appreciate that the blocking body  15  may be any shape that will allow the blocking body  15  to be introduced into the well  8  and to move to engage a desired downhole element. Regardless of shape, at least a portion of the blocking body  15  may comprise a material that can perturb a magnetic field, for example a magnetic material. This magnetic material provides the blocking body  15  an operative configuration to create a detectable signal. For example, in some embodiments of the present disclosure, the blocking body  15  comprises a shell  17  as illustrated in  FIG. 10A  and the shell is at least partially made of a magnetic material. In other embodiments, the blocking body  15  may comprise a core  19  located therein and the core  19  is at least partially made up of a magnetic material. In some embodiments of the present disclosure, the blocking body  15  may include both the shell  17  and the core  19 . In other embodiments, the entire blocking body  15  may be formed of a magnetic material. The magnetic material for the blocking body  15  may be selected from a group consisting of ferrous alloy such as, by way of non-limiting example, alloy steels, carbon steels or cast iron although it will be appreciated that other metals may be useful here as well, provided that they can perturb a magnetic field. 
     In some embodiments of the present disclosure, the blocking body  15  may comprise a radio frequency identification tag (RFID) and the RFID tag provides the blocking body  15  with an operative configuration to create the detectable signal. The detection tool  20  includes a sensor or reader that can detect when the radio signal—and therefore the blocking body  15 —is approaching, passing through or moving away from the detection tool  20 . In some embodiments of the present disclosure, the detection tool  20  comprises sensors that can detect perturbations in a magnetic field and/or sensors that can detect a radio signal generated by and RFID tag. In some embodiments, a plurality of blocking bodies  15  may be available for use. Each blocking body  15  comprises a RFID having a unique identifier for indicating the identity of the blocking body  15 . When a block body  15  approaching, passing through or moving away from the detection tool  20 , the detection tool  20  uses the sensor or reader to detect the unique identifier of the RFID of the blocking body  15  to determine which blocking body  15  is approaching, passing through or moving away from the detection tool  20 . 
     Although in above embodiments, the sleeves  40  are secured to the outer surface  26  of the tubular body  22 , in some alternative embodiments as shown in  FIG. 11 , the tubular body  22  comprises one or more blind bores  44  radially inwardly extending from the outer surface thereof into the tubular body  22  without penetrating the wall thereof. Each blind bore  44  at least partially receives a sleeve  40  and mounting it therein by suitable means such as threading, gluing and/or the like. 
     In some alternative embodiments as shown in  FIG. 12 , the detection tool  20  comprises a detection clamp  45  removably coupled to the tubular body  22 . The detection clamp  45  comprises one or more blind bores  44  radially inwardly extending from the outer surface thereof into the detection clamp  45  the wall thereof. Each blind bore  44  at least partially receives a sleeve  40  and mounting it therein by suitable means such as threading, gluing and/or the like. 
     In some alternative embodiments as shown in  FIG. 13 , the detection tool  20  comprises a detection clamp  45  removably coupled to the tubular body  22 . The detection clamp  45  comprises one or more bores  44  radially inwardly extending therethrough. Each bore  44  at least partially receives a sleeve  40  and mounting it therein by suitable means such as threading, gluing and/or the like. 
     In some alternative embodiments as shown in  FIG. 14 , the detection tool  20  comprises a detection clamp  45  having one or more bores sleeves  40  attached thereto as described above. In these embodiments, the detection clamp  45  comprises two clamp pieces  45 A and  45 B removably coupled to the tubular body  22  using suitable means such as bolts. 
     Those skilled in the art will appreciate that, during operation, metal filings and/or debris may be generated due to wearing of various metal components. The magnetic field associated with the detection tool  20  may trap the metal filings onto the inner surface of the central passage  34 . To remove the trapped filings from the detection tool  20 , in a cleaning process, an operator may periodically separate the two clamp pieces  45 A and  45 B and remove them from the tubular body  22 . As the magnets  60  and  84  of the magnetic stacks  70  and the sensor stacks  80  are coupled to the clamp pieces  45 A and  45 B, the magnetic field thereof are thus removed from the tubular body  22  when the clamp pieces  45 A and  45 B are removed therefrom. The trapped filings on the inner surface of the central passage  34  thus fall off and are removed from the detection tool  20 . After cleaning, the operator may then couple the two clamp pieces  45 A and  45 B back to the tubular body  22 . 
     In some alternative embodiments as shown in  FIGS. 15 and 16 , the detection tool  20  comprises a clamp or ram  45  removably coupled to the tubular body  22 . The detection clamp  45  comprises a base or anchor  132  for (removably or non-remobaly) mountable to the tubular body  22 . Two clamp pieces  45 A and  45 B are rotatably coupled to the anchor  132  such that, when the anchor  132  is mounted to the tubular body  22 , the two clamp pieces  45 A and  45 B may be rotated to a closed condition about the tubular body  22  as shown in  FIG. 16 , or rotated to an open condition away from the tubular body  22  as shown in  FIG. 15 . One or more bores sleeves  40  are attached to the two clamp pieces  45 A and  45 B as described above. 
     The detection clamp  45  also comprises one or more actuators  134  coupled to the two clamp pieces  45 A and  45 B for rotating the two clamp pieces  45 A and  45 B to the open or closed conditions. An electrical or hydraulic motor (not shown) is used for driving the one or more actuators  134  to rotate the two clamp pieces  45 A and  45 B. In operation, the motor may be programmed to periodically rotating the two clamp pieces  45 A and  45 B to the open condition away from the tubular body  22  to clean any filings trapped in the detection tool  20 . After cleaning, the motor rotates the two clamp pieces  45 A and  45 B to the closed condition about the tubular body  22 . 
     In some embodiments, the motor comprises a wired or wireless communication means for receiving commands from a control center (not shown). In operation, an operator in the control center may remotely command the motor to rotate the two clamp pieces  45 A and  45 B to the open condition away from the tubular body  22  to clean any filings trapped in the detection tool  20 . After cleaning, the operator in the control center may command the motor to rotate the two clamp pieces  45 A and  45 B to the closed condition about the tubular body  22 . 
     Although in above embodiments, the detection clamp  45  comprises two clamp pieces  45 A and  45 B, in some alternative embodiments the detection clamp  45  may comprise more than two clamp pieces. 
     Although in above embodiments, the sleeves  40  including the magnets  60  and  84  and the sensors  82  are coupled to the detection clamp  45 , in some alternative embodiments, only the magnets  60  and  84  are coupled to the detection clamp  45  and the sensors  82  are directly coupled to the tubular body  22 . 
     Although in above embodiments, the two or more clamp pieces  45 A and  45 B are roatably configurable to the open and closed conditions, in some alternative embodiments, the two or more clamp pieces  45 A and  45 B may be configurable to the open condition away from the tubular body  22  and the closed condition about the tubular body  22  by any other suitable means. For example, in some embodiments, the two or more clamp pieces  45 A and  45 B may be radially movable towards or away from the tubular body  22  by the actuation of one or more actuators  134  to be configured to the open and closed conditions, respectively.