Patent Publication Number: US-11021920-B2

Title: Downhole tools and methods of controlling downhole tools

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-Provisional patent application Ser. No. 15/840,051, filed Dec. 13, 2017, which is a continuation of U.S. Non-Provisional patent application Ser. No. 14/677,848, filed Apr. 2, 2015, the disclosures of which are incorporated by reference herein in their entireties for all purposes. 
    
    
     FIELD OF THE DISCLOSURE 
     The disclosure generally relates to downhole tools and methods of controlling downhole tools. 
     BACKGROUND 
     Downhole tools, such as tractors, often need to negotiate obstacles in wellbores. However, individual control of arms of traditional tractors is not possible; thereby, hindering the ability of traditional tractors to negotiate restrictions in the wellbore or isolate a failed motor. 
     SUMMARY 
     An embodiment of a downhole tool may include a plurality of arm assemblies. Each of the arm assemblies can include an arm configured to expand and retract and an actuator. The downhole tool may also include a hydraulic bus. The hydraulic bus may be in fluid communication with the plurality of arm assemblies; and a plurality of flow control devices. The flow control devices can be configured to selectively isolate individual arm assemblies of the plurality of arm assemblies from the hydraulic bus. 
     Another embodiment of the downhole tool may include a plurality of arm assemblies, and each of the arm assemblies may include an arm configured to expand and retract and an actuator. The plurality of arm assemblies can be in fluid communication with a hydraulic bus. The downhole tool may also include a plurality of flow control devices; and the flow control devices can be configured to selectively isolate individual arm assemblies of the plurality of arm assemblies from the hydraulic bus. The downhole tool can also include a control module in communication with the plurality of flow control devices, and a sensor can be in communication with the control module. 
     An example method of controlling arm activation of a downhole tool can include providing fluid to a hydraulic bus in fluid communication with a plurality of arm assemblies; and isolating individual arm assemblies of the plurality of arm assemblies from the hydraulic bus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a schematic of an embodiment of the downhole tool. 
         FIG. 2  depicts a schematic of another embodiment of a downhole tool. 
         FIG. 3  depicts a flow diagram of an example method of controlling arm activation of a downhole tool. 
         FIG. 4  depicts a schematic of an example constant force actuator in a closed position. 
         FIG. 5  depicts a schematic of the example constant force actuator of  FIG. 4  in an open position. 
         FIG. 6  depicts a schematic of another example constant force actuator in a closed position. 
         FIG. 7  depicts a schematic of the constant force actuator in  FIG. 6  in a partially radially expanded state. 
         FIG. 8  depicts a schematic of the constant force actuator of  FIG. 6  in a fully radially expanded state. 
         FIG. 9  depicts a schematic of an assembly including an anchor connected with a downhole tool. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. 
     An embodiment of a downhole tool includes a plurality of arm assemblies. The arm assemblies include an arm configured to expand and retract and an actuator. The example downhole tool also includes a hydraulic bus in fluid communication with the plurality of arm assemblies; and a plurality of flow control devices. The flow control devices are configured to selectively isolate individual arm assemblies of the plurality of arm assemblies from the hydraulic bus. 
     An embodiment of a downhole tool can also include a control module in communication with the plurality of flow control devices and at least one sensor. The sensor can be a caliper located on the downhole tool below a drive section, and the control module can receive wellbore diameter data from the caliper and selectively isolate individual arm assemblies of the plurality of arm assemblies according to the wellbore diameter data. The control module can be a microprocessor configured to receive the wellbore data and control the plurality of flow control devices to selectively isolate individual arm assemblies, allowing selective closure of the arm assemblies according to the wellbore diameter data. The control module can also receive feedback from motors associated with the arm assemblies and control the plurality of flow control devices to isolate arm assemblies associated with a failed motor from the hydraulic bus. 
       FIG. 1  depicts a schematic of an embodiment of a downhole tool. The downhole tool  100  can contain a control module  110 , a hydraulic module  120 , a first drive module  130 , a second drive module  140 , and a sensor  150 . 
     The control module  110  can contain one or more microprocessors configured to control components of the tool. For example, one microprocessor can control a pump in the hydraulic module  120 , a second microprocessor can control flow control devices  136  and  146 , and a third microprocessor can control motors  138  and  148 . Of course, each motor can be controlled by two independent microprocessors. Two microprocessors can also control the flow control devices. Other now known or future known configurations and methods of controlling the components of the downhole tool  100  can also be used. 
     The hydraulic module  120  can include a hydraulic system including a pump, motor, valves, and flow lines. Any now known or future known hydraulic systems can be used. 
     The flow control devices  136  and  146  can be any adjustable flow control device. The flow control devices can be solenoid valves. 
     The sensor module  150  can be a caliper or other sensor configured to acquire downhole data. The downhole data can include wellbore diameter, temperature, pressure, downhole tool velocity, or combinations thereof. 
     The hydraulic module  120  can provide pressurized fluid to the drive modules  130  and  140  via hydraulic bus  112 . 
     The first drive module  130  can include the first flow control device  136 , the first motor  138 , and a first arm assembly  132 . The first arm assembly  132  can include an actuator  133  and a first arm  134 . 
     The second drive module  140  can include the second flow control device  146 , a second arm assembly  142 , and the second motor  148 . The second arm assembly  142  can include a second actuator  143  connected with a second arm  144 . 
     The actuators  133  and  143  can be any now known or future known activation device. An illustrative actuator is hydraulically operated, and as a piston is moved the connected arm is radially expanded. The arms  134  and  144  can be connected with the actuators  133  and  143  using any now known or future known techniques. The arms  134  and  144  can have a wheel, roller, or the like on an end thereof. The wheel, roller, or the like can be driven by the first motor  138  to provide movement to the downhole tool. 
     The first flow control device  136  can be selectively controlled to allow fluid communication of a first arm activation assembly  132  with the hydraulic bus  112 , and the second flow control device  146  can be selectively controlled to allow fluid communication between the second arm activation assembly  142  and the hydraulic bus  112 . For example, if the control module determines that the first motor  138  has stopped working, the control module  110  can close the first flow control device; thereby, preventing communication between the hydraulic bus  112  and the first arm activation device  133 . Accordingly, the first arm activation assembly  133  will not radially expand the first arm  134 , and the second arm  144  can remain radially expanded. 
     In another example, the sensor module  150  can determine that there is a reduction in the wellbore, the speed of the downhole tool can be determined using now known techniques or future known techniques, and distance of each drive module  130  and  142  can be known. The control module  150  can use these parameters to determine that there is an obstruction and if the arms of the drive module need to be retraced and when the first arm  134  and the second arm  144  need to be retracted. To allow retraction of the arms  134  and  144 , the control module  110  can selectively close the flow control devices  136  and  146  respectively. 
       FIG. 2  depicts a schematic of another embodiment of a downhole tool. The downhole tool  200  can include a control module  210 , a sensor module  250 , a first drive module  230 , a second drive module  240 , a hydraulic bus  112 , a hydraulic module  220 , and a motor module  260 . 
     The control module  210  can include one or more microprocessors and other equipment allowing the control module  210  to control the components of the downhole tool  200 . 
     The motor module  260  can be operatively connected with the drive modules  230  and  240 , allowing the motor module  260  to provide power to both drive modules  230  and  240 . The motor module  260  can be connected with the drive modules  230  and  240  using a drive shaft, gear box, continuous variable transmission, other now known or future known drive components, or combinations thereof. 
     The first drive module  230  can include a first flow control device  236  and a first arm assembly  232 . The first arm assembly  232  can include an actuator  233  and a first arm  234 . 
     The second drive module  240  can include a second flow control device  246  and second arm assembly  242 . The second arm assembly  242  can include a second actuator  243  connected with a second arm  244 . 
     The actuators  233  and  243  can be any now known or future known activation device. An illustrative actuator is hydraulically operated, and as a piston is moved the connected arm is radially expanded. The arms  234  and  244  can be connected with the actuators  233  and  243  using any now known or future known techniques. The arms  234  and  244  can have a wheel, roller, or the like on an end thereof. The wheel, roller, or the like can be driven by the motor module  260  to provide movement to the downhole tool. 
     The sensor module  250  can be a caliper or other sensor configured to acquire downhole data. The downhole data can include wellbore diameter, temperature, pressure, downhole tool velocity, or combinations thereof. 
       FIG. 3  depicts a flow diagram of an example method of controlling arm activation of a downhole tool. The method  300  can include providing fluid to a hydraulic bus in fluid communication with a plurality of arm assemblies (Block  310 ). The method  300  can also include isolating one or more arm assemblies from the plurality of arm assemblies from the hydraulic bus while maintaining the other arm assemblies of the plurality of arm assemblies in communication with the hydraulic bus (Block  320 ). Isolating can include closing one or more flow control devices. The one or more arm assemblies of the plurality of arm assemblies can be isolated from the hydraulic bus in response to data acquired by a sensor in communication with a control module. 
     In one or more embodiments each of the arm assemblies of the plurality of arm assemblies can include a constant force actuator. The constant force actuator disclosed herein can be used with other downhole tools as well. For example, the constant force actuator can be used to expand a centralizer, a caliper, an anchor, or other radially expanding components of a downhole tool. 
       FIG. 4  depicts a schematic of an example constant force actuator in a closed position.  FIG. 5  depicts a schematic of the example constant force actuator of  FIG. 4  in an open position. 
     Referring now to  FIG. 4  and  FIG. 5 , the constant force actuator  400  includes a fixed support  406 , an arm  402 , a link  404 , and a slide  408 . The constant force actuator  400  has a closed height, represented as Hclosed, and an open height, represented as Hopen. The actuator  400  can be moved from the closed position by applying an axial force, represented as Fx, to the slider  408 . The slide  408  will move the link  404 , causing the arm  402  to pivot about a connection on the fixed support  406 . The pivoting will continue until the arm contacts a borehole wall or other obstruction, and then a radial force, represented as Fy, will be exerted on the borehole wall or other obstruction at a point S. 
     The constant force actuator  400  can have a force ratio of Radial Force=Fy/Fx. The constant force actuator  400  can have an expansion ratio as Expansion Ratio=Hopen/Hclosed. The constant force actuator can have a constant radial force for any position of the slider  408  within the range defined by Hopen and Hclosed. 
       FIG. 6  depicts a schematic of another example constant force actuator in a closed position.  FIG. 7  depicts a schematic of the constant force actuator in  FIG. 6  in a partially radially expanded state.  FIG. 8  depicts a schematic of the constant force actuator of  FIG. 6  in a fully radially expanded state. 
     Referring now to  FIG. 6 ,  FIG. 7 , and  FIG. 8 , the constant force actuator  600  includes a first arm  602 , a second arm  603 , a first link  604 , a second link  605 , a fixed support  612 , a slider  608 , a first moveable support  614 , a second movable support  615 , and a bar  616 . In one or more embodiments, the bar  616  can be omitted. 
     The slider  608  can have an axial force, designated as Fx, applied thereto, and as the slider  608  moves in the direction of the axial force Fx, the distance between point P and point P′ is decreased and the arms  602  and  603  can expand radially. The movable support  614  and  615  allow the pivots Q and Q′ connected with the arms  602  and  603 , respectively, to translate axially. The arms  602  and  603  can radially expand until coming into contact with a borehole wall or other obstruction. Upon contacting the borehole wall or other obstruction, a radial force, designated as Fy, can be applied to the borehole wall or other obstruction. The radial force Fy will be applied at points S and S′. In one or more embodiments, the constant force actuator  600  can be used as a centralizer or anchor. In an embodiment where the constant force actuator  600  is used as an anchor, the radial force Fy can be used to secure a downhole tool within the borehole. The constant force actuator  600  can have an expansion ratio from about 3:1 to about 7:1, and the consistency of the force ratio can be preserved throughout the expansion. 
       FIG. 9  depicts a schematic of an assembly including an anchor connected with a downhole tool. 
     The system  900  can include a downhole tool  910 , a field joint  920 , an anchor module  930 , a constant force actuator  932 , and a conveyance  940 . 
     The downhole tool  910  can be any one described herein, a milling tool, a shifting tool, the like, or a combination thereof. The constant force actuator  932  can be any one of those described herein. The constant force actuator  932  can have axial force applied thereto by an electric linear actuator, a motor, a hydraulic actuator, other now known or future known force generating devices, or combinations thereof. 
     The conveyance  940  can be a wireline, slickline, coil tubing, or the like. 
     The system  900  can be conveyed into a borehole, and upon reaching a desired location in the borehole, the constant force actuator  932  can be activated to anchor the system  900  in the borehole to allow a downhole operation to be performed. The constant force actuator  932  can be retracted upon completion of the downhole operation, the system  900  can be moved to perform another downhole operation or retrieved to the surface. 
     Although example assemblies, methods, systems have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers every method, apparatus, and article of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.