Patent Application
20210032974
Oil and gas industry processes include exploration, drilling, logging, extraction, transportation, refinement, retail, and so forth, of natural resources, such as oil, gas, and water. The natural resources may be located underground and, as such, a drilling system may be used to perform some of the processes. For example, a drilling system may form wellbores into the earth formation to discover, observe, analyze, or extract the natural resources.
When drilling, forces acting upon the drilling system may negatively impact the performance of the drilling system. For example, such forces may take energy input into the drilling system and create vibration or heat (e.g., through friction). When vibration and heat are generated, some of the input energy is lost and the system operates at a reduced efficiency. Wellbores may also be planned to extend in a particular direction, and forces acting on the drilling system may affect trajectory of a drill bit, thereby causing the drill bit to drill a wellbore that deviates from the planned trajectory or path.
During operation of a drilling system to form a wellbore, certain forces may affect components of the drilling system to cause deformations of the components. Thus, determining the deformation of the components may facilitate determining the forces imparted onto the components. It may be difficult to use conventional techniques to directly determine the deformation of certain components (e.g., by using sensors attached to the certain components), such as a drill collar, of the drilling system due to cost, complexity, or inherent disadvantages of implementing the conventional techniques (e.g., creating channels in the drill collar). Thus, the presently disclosed systems and methods may indirectly determine the deformation of such components by determining the deformation of alternative components, and then using the determined deformation of alternative components to determine the forces imparted onto the drilling system and/or to set an operation of the drilling system. In some embodiments, the determined forces may then be used to estimate a position or trajectory of the drilling system to facilitate, for example, steering of the drilling system.
Various refinements of the features noted herein may exist in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. Again, the brief summary herein is intended only to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter.
In some embodiments, a drilling system includes an internal assembly and a drill collar coupled to and enclosing the internal assembly. The internal assembly has a chassis and a strain gauge coupled to the chassis, and the strain gauge can output a signal associated with a strain deformation of the internal assembly. The coupling of the internal assembly and drill collar are such that strain deformation of the drill collar causes the strain deformation of the internal assembly.
In some embodiments, a drilling component includes a chassis having a compartment, a rod within the compartment, and a sensor coupled to the rod. The sensor can determine a parameter associated with a strain deformation of the rod.
In some embodiments, a bottom hole assembly (BHA) of a drill string includes a chassis, a controller at least partially within the chassis, a drill collar coupled to and enclosing at least a portion of the chassis, and a sensor coupled to the chassis and communicatively coupled to the controller. The sensor may transmit a signal indicative of a bending strain of the chassis to the controller.
In some embodiments, a BHA of a drill string includes a chassis, a plate coupled to the chassis, and a strain gauge coupled to the plate. The strain gauge is configured to output a signal associated with a strain deformation of the plate.
In some embodiments, a BHA of a drill string includes an electronics board configured to operate the BHA and a strain gauge coupled to the electronics board. The strain gauge transmits a signal indicative of a strain deformation to the electronics board to control operation of the BHA based at least partially on the signal indicative of the strain deformation to the electronics board.
In some embodiments, a plate within a bottom hole assembly includes a first surface, a second surface opposite the first surface, and a torsion strain gauge coupled to the first surface or the second surface. Two in-plane bending strain gauges are also each coupled to the first surface or each coupled to the second surface, and are on opposite sides of a centerline of the plate and while being aligned along a lateral axis of the plate. A first out-of-plane bending strain gauge is coupled to the first surface of the plate along the centerline of the plate and a second out-of-plane bending strain gauge is coupled to the second surface of the plate along the centerline and aligned with the first out-of-plane bending strain gauge along a vertical axis of the plate. First and second axial strain gauges are also coupled to the first and second surfaces of the plate, respectively, along the centerline of the plate and aligned with each other along the vertical axis.
In some embodiments, an electronics board within a bottom hole assembly, includes a board. Coupled to the board are at least one torsion strain gauge, at least one in-plane strain gauge, at least one out-of-plane strain gauge, and at least one axial strain gauge. The torsion strain gauge measures torsion strain deformation of the board and is isolated from measuring in-plane bending, out-of-plane bending, and axial strain deformation of the board. The in-plane strain gauge measures in-plane bending strain deformation of the board and is isolated from measuring torsion, out-of-plane bending, and axial strain deformation of the board. The out-of-plane strain gauge measures out-of-plane bending strain deformation of the board and is isolated from measuring torsion, in-plane bending, and axial strain deformation of the board. The axial strain gauge measures axial strain deformation of the board and is isolated from measuring torsion, in-plane bending, and out-of-plane bending strain deformation of the board.
The above summary recites aspects of some embodiments disclosed herein, and presents aspects merely to provide the reader with a brief summary of certain embodiments. This summary is not intended to provide a comprehensive recitation of features of each embodiment, and is not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth in the summary, but which are described or illustrated in the description, drawings, or claims.
In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings are drawn to scale. The drawings that are drawn to scale are illustrative only, and while being to scale for some embodiments, are not to scale for other embodiments. Understanding that the drawings depict some example embodiments and that various aspects of the disclosure will be better understood upon reading the following description and upon reference to the drawings, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Embodiments of the present disclosure relate generally to determining strain deformations, and more particularly to determining strain deformations within a downhole drilling system. More particularly still, internal assemblies or components of a downhole drilling system may include strain gauges or other sensors for determining the strain experienced by a component of the downhole drilling system. Optionally, strain measurements are made using sensors that are isolated from other modes of bending or strain.
In an illustrative aspect, embodiments of the present disclosure are directed to strain determinations within a drilling system that uses a drill string to form a wellbore extending to or toward a hydrocarbon field. The drilling system may rotate a full or partial length of the drill string and drive a drill bit that cuts away into the geological formation in which hydrocarbons are located. During operation, the drilling system may determine or infer a position, path, or movement of the drill string, to regulate operation of the drilling system. As an example, the drilling system may drive the drill string—including the drill bit—toward a target location in the geological formations, while monitoring and controlling the movement of the drill string to ensure that the drill string is moving as desired through the geological formations.
During operation of the drilling system, forces may act on the drill string and impact a performance of the drilling system or affect a structural integrity of a component of the drill string. Example forces include weight imparted by gravity, fluid pressure exerted by drilling fluid, friction from engagement between the drill string and the geological formation, torque on the drill string (or a portion thereof) generated by a surface system or downhole motor, intermolecular forces occurring as a result of increased temperature on account of friction or downhole conditions, and the like. In some circumstances, the forces may negatively affect operation of the drilling system, such as by moving the drill string away from the target position, by reducing efficiency by creating vibration or heat, or the like.
The forces on the drill string may also structurally change components of the drill string. Thus, identifying the structural changes to the drill collar may allow inference or other determination of the imparted forces, and may be used to establish or control the drilling system operation to avoid or limit undesired results of forces imparted onto the drill collar. Embodiments of the present disclosure primarily discus the determination of structural changes associated with a strain deformation, including torsional strain, out-of-plane bending strain, in-plane bending strain, axial strain, and combinations thereof; however, other types of strain deformations (e.g., shear strain) may be determined in additional or alternative embodiments.
Within a downhole system, it may be difficult to directly determine the strain deformations of a drill collar or other component (e.g., by using sensors on the drill collar). For instance, certain types of strain deformations may affect the readings of other types of strain deformations (e.g., torsional strain affects an out-of-plane strain reading, etc.). In another example, it may be difficult, inefficient, or both difficult and inefficient to couple the sensor directly to the drill collar or other component in a manner that enables the sensor to determine the structural changes of the component while the drill string is in operation. For example, the sensor may instead be coupled directly onto a drill collar in a controlled environment (e.g., a temperature-controlled laboratory) and by trained personnel to enable the sensor to provide accurate readings. As such, implementing the sensor may increase a cost associated with manufacturing the drill string or may operate only in a narrow range of applications that may not include a harsh downhole environment. Moreover, the sensor may have to be wired to electrical components within the drill string, requiring a channel to be cut through the supporting component, and potentially affecting the structure of the component by weakening the component integrity or creating a site for stress concentrations.
Thus, it is presently recognized that implementing a sensor that determines the structural change of a component (e.g., through an indirect means such as by not being mounted on the component itself) may reduce a cost associated with determining the forces acting on the component. As such, some embodiments of the present disclosure are directed to sensors and processes in which the sensor is coupled to an alternative component of the drill string (e.g., in relation to the drill collar or other component where strain is being measured) and nevertheless detects forces on the other component. The alternative component may be coupled to the first component (e.g., drill collar) such that strain deformations of the drill collar are transmitted onto the alternative component. The sensor may then determine the transmitted strain deformations, which are associated with the strain deformations of the drill collar. In some embodiments, the alternative component is another existing component of the drill string, such as a chassis or an electronic control board coupled to the drill collar. Thus, the sensor may directly determine strain deformations of the existing component, and indirectly determine the strain deformation of the drill collar or other component supporting the existing component. In additional or alternative embodiments, the alternative component is a supplemental component that is coupled to an existing component of the drill string. The supplemental component may enable the sensor to be coupled to an existing component more easily than by directly attaching the sensor to the existing component. In this way, the sensor may determine strain deformations of the supplemental component, and strain deformations of the supplemental component can correspond with strain deformations of the existing component, the drill collar, or both. In any case, the drilling system may be operated or a structural condition of the drilling system may be monitored based on the strain deformations determined by the sensor.
To help illustrate the techniques described herein,
The drilling system 10 also includes a surface system 22 that rotates and drives the drill string 16. In some embodiments, the drilling system 10 includes a kelly system having a rotary table 24, a kelly 26, a hook 28, and a rotary swivel 30. The drill string 16 may be coupled to the hook 28 through the kelly 26 and the rotary swivel 30. The rotary swivel 30 may be suspended from the hook 28 that is attached to a traveling block (not shown) that drives the drill string 16 relative to the surface system 22 along an axis 32 that extends through a center of the wellbore 12. The rotary swivel 30 may permit rotation of the drill string 16 relative to the hook 28, and the rotary table 24 may rotate in a rotational direction 33 to drive the drill string 16 to rotate concentrically about the axis 32. Alternatively, the drilling system 10 may be a top drive system that rotates the drill string 16 via an internal drive (e.g., an internal motor) of the rotary swivel 30. That is, the drilling system 10 may not use the rotary table 24 and the kelly 26 to rotate the drill string 16. Rather, the internal drive of the rotary swivel 30 may drive the drill string 16 to rotate in the rotational direction 33 relative to the hook 28 concentrically about the axis 32. In still other embodiments, a downhole motor (e.g., positive displacement motor, turbine motor, etc.) may include a drive shaft that is coupled to the drill bit 20 and used to rotate the drill bit 20. The drill string 16 may not rotate in such embodiments, or may rotate but with the downhole motor providing the primary rotational force to the drill bit 20.
In any case, as the surface system 22 or downhole motor rotates the drill string 16, and weight is applied to the drill bit 20 (e.g., through gravity), the drill string 16 may be driven in axial directions to engage the drill string 16 with the geological formations 14. For example, the drill string 16 may be driven into the geological formation 14 through the wellbore 12 in a first axial direction 34, which may be a generally downward/downhole vertical direction. Additionally, the drill string 16 may be removed from the wellbore 12 in a second axial direction 36 opposite the first axial direction 34. That is, the second axial direction 36 may be a generally upward/uphole vertical direction. The axial movement of the drill string 16 with rotational movement of all or a portion of the drill string 16 may facilitate engagement of the drill bit 20 with the geological formations 14. Although
The surface system 22 may also include mud or drilling fluid 40 that may be directed into the drill string 16 to cool and lubricate the drill bit 20, and to carrying cuttings upwardly to the surface. Additionally, the drilling fluid 40 may exert a mud pressure on the geological formations 14 to reduce likelihood of fluid from the geological formations 14 flowing into or out of the wellbore 12. In some embodiments, the drilling fluid 40 is stored in a tank or pit 42 located at the well site. A pump 44 may fluidly couple the pit 42 and the swivel 30, in which the pump 44 may deliver the drilling fluid 40 to the interior of the drill string 16 via a port in the swivel 19, causing the drilling fluid 40 to flow downwardly through the drill string 16 in the first axial direction 34. The drilling fluid 40 may also exit the drill string 16 via ports in the drill bit 20 or other portions of the drill string 16, and flow into the wellbore 12 toward the surface (e.g., toward the surface system 22). While drilling, the drilling fluid 40 may circulate upwardly in the second axial direction 36 through an annulus region between the outside of the drill string 16 and a wall of the wellbore 12, thereby carrying drill cuttings away from the bottom of the wellbore 12. Once at the surface, the returned drilling fluid 40 may be filtered to separate the cuttings, and the fluid can be conveyed back to the pit 42 for recirculation and reuse.
The BHA 18 of the drilling system 10 of
The LWD module 120, the MWD module 130, or both, may each be housed in a special type of drill collar that couples to the drill string and which may contain one or more types of logging or measurement tools. In general, the LWD module 120 may include capabilities for measuring, processing, and storing formation or environmental information, and the MWD module may contain one or more devices for measuring characteristics of the drill string 16 or drill bit 20, as well as for communicating with surface equipment. In the drilling system 10 of
In certain embodiments, the MWD module 130 includes an apparatus for generating electrical energy. For example, the MWD module 130 may include a mud turbine generator that generates electrical energy from the flow of the drilling fluid 40. In additional or alternative embodiments, the drilling system 10 includes a power source 148, such as an electrical generator or an electrical energy storage device, that supplies energy to the drilling system 10. In any case, electrical energy may be used to operate the aspects of the drilling system 10, such as to control the BHA 18.
The BHA 18 may further include a motor 150, a rotary-steerable system (RSS) 152, or other modules (e.g., cross-overs, hydraulic release, circulation, etc.) coupled to the drill bit 20. A motor 150, RSS 152, or other module may be directly coupled to the LWD module 120, MWD module 130, other modules, or to the drill bit 20, or via one or more additional tubulars 154. The motor 150 and the RSS 152 are used to regulate operation of the drill bit 20 to engage with the geological formations 14. For example, the RSS 152 may orient the drill bit 20 in a desirable direction while the motor causes the drill bit 20 to rotate continuously to drill the wellbore 12. Generating continuous rotation may enable improved transportation of drilled cuttings to the surface, better cutting of the wellbore 12 (e.g., improved wellbore quality, reduced stick-slip or bit whirl, etc.), limited stress imparted upon the drill bit 20 by the geological formations 14, and so forth. Furthermore, the RSS 152 may enable control of the engagement of the drill string 16 with the geological formations 14. By way of example, the RSS may place the drill string 16 in communication with the surface system 22. As such, the surface system 22 may control a direction or path for the drill string 16 to form the wellbore 12 or a manner the drill string 16 engages with the geological formations 14 (e.g., a rotation vs. sliding of the drill string 16).
In some embodiments, the drill string 16 includes or is communicatively coupled to a data processing system 160 that can adjust the operation of the drilling system 10, such as to direct the drill string 16 through the wellbore 12 or the path of the drill string 16 when extending the wellbore 12. The data processing system 160 may include one or more processors 162, such as a general purpose microprocessor, an application specific processor (ASIC), or a field programmable gate array (FPGA) or other programmable logic device, or combinations of the foregoing. Processors 162 may execute instructions stored in a memory 164 or other storage 166, which may be read-only memory (ROM), random-access memory (RAM), flash memory, optical storage media, a hard disk drive, and the like. The data processing system 160 may further be communicatively coupled to a sensor 167 that may determine an operating parameter of the drill string 16. As an example, the sensor 167 may be a strain gauge (e.g., any embodiment of a strain gauge or strain gauge circuit discussed herein, or combinations thereof) that facilitates determining a strain or deformation of a section of the BHA 18, and the sensor 167 may directly or through other components transmit signals or feedback to the data processing system 160 indicative of the determined strain. The data processing system 160 may operate the drilling system 10, such as to adjust the direction through which the drill string 16 forms the wellbore 12, based on the feedback received from the sensor 167.
Although the illustrated embodiment of the data processing system 160 is located external to the drill string 16, the data processing system 160 may alternatively be wholly or partially a part of the drill string 16, such as within the BHA 18. The data processing system 160 may include a device proximate the drilling operation (e.g., at the surface system 22, in the BHA 18, etc.) or a remote data processing device located away from the drilling system 10, such as a mobile computing device (e.g., tablet, smart phone, laptop, desktop computer, etc.) or a server remote from the drilling system 10. In any case, the data processing system 160 may process downhole measurements in real-time, in near real-time, or sometime after the data has been collected. In general, the data processing system 160 may store and process collected data, such as data collected by the BHA 18 via the LWD module 120, the MWD module 130, the sensor 167, or any suitable telemetry (e.g., electrical signals pulsed through the geological formations 14 or mud pulse telemetry using the drilling fluid 40). In further embodiments, separate data processing systems 160 may be used to direct, orient, or control the drill string 16, to rotate the drill string 16 (e.g., with surface torque, by flowing fluid to a downhole motor, etc.), or to raise or lower the drill string 16.
In some embodiments, the data processing system 160 may also include a user interface 168 that allows a user to interact with the data processing system 160. For example, the user may input properties, instructions (e.g., control commands), or parameters to the data processing system 160 via the user interface 168. To this end, the user interface 168 may include a button, a keyboard, a microphone, a mouse, a trackpad, a touch screen, an audio input device, or the like. The user interface 168 may also include a display, which may be any suitable electronic display that is displays visual representations of information, such as graphical representations of collected data.
Further still, the data processing system 160 may include input/output (I/O) ports 170 that enable the data processing system 160 to communicate with various electronic devices. For example, the I/O ports 170 may enable the data processing system 160 to directly couple to another electronic device (e.g., a remote or mobile device) to enable data to transfer between the data processing system 160 and the electronic device. The I/O ports 170 may additionally or alternatively enable the data processing system 160 to indirectly couple to other electronic devices. In another example, the I/O ports 170 may enable the data processing system 160 to couple to a network, such as a personal area network (PAN), a local area network (LAN), a wide area network (WAN), or any combination of the foregoing. Accordingly, in some embodiments, the data processing system 160 does one or more of receiving data (e.g., as signals) from another electronic device (e.g., a base-station control system) via the I/O ports 170 or communicating data to another electronic device via the I/O ports 170.
The BHA 18 may include a mandrel assembly or other internal assembly 201, which generally refers to an assembly of components within and potentially fully or partially enclosed by the drill collar 200. The internal assembly 201 may extend along at least a partial length of the drill collar and can include multiple components that can each be referred to as a chassis. For instance, a first chassis 202 may support or include physical components, tools, or sensors of the internal assembly 201, and is in some embodiments referred to as a tool chassis. A second chassis 204 may support other physical components, tools, or sensors of the internal assembly 201, and is in some embodiments referred to as an instrumentation chassis 204. In at least some embodiments, the chassis 204 encloses or supports instrumentation tools of the BHA 18, such as the sensor 167.
The chasses 202, 204 may have any suitable construction. For instance, the chassis 202, the chassis 204, or both, may have an annular construction. Chassis 202, for instance, is illustrated as being annular and having a flow path therethrough. Chassis 204 of this embodiment is shown as having an internal compartment, but without a flow path extending fully therethrough. In some embodiments, the chassis 202, the chassis 204 may include or be formed as a flow diverter 206 that directs the drilling fluid 40 through the BHA 18 to the drill bit 20. The flow diverter 206 in
As mentioned herein, it may be difficult or inefficient to implement a sensor (e.g., a strain gauge) to determine the strain deformation associated with the BHA 18 to control operation of the BHA 18. For example, in conventional approaches, placing a sensor on the drill collar 200 to directly determine the strain deformation of the drill collar 200 may be expensive or difficult to implement (e.g., having limited robustness making it unsuitable for downhole use). As such, the sensor 167 may be positioned in an alternative position, such as within the internal assembly 201 or within a pocket or cavity formed in the BHA 18 (e.g., along the chassis 204, in a lid/cover of an internal assembly 201, or in a pocket or cavity on an internal surface of the drill collar 200), or an alternative sensor may be used to determine the strain deformation associated with the BHA 18. In some embodiments, the sensor 167 in alternative locations (e.g., in a lid of a pocket or a plate attached to a lid) may enable or facilitate further embodiments, such as pressure measurement. In some embodiments, the sensor 167 optionally does not directly determine the strain deformation of the drill collar 200 (e.g., using a sensor on the drill collar 200 where strain is desired), but may determine another parameter that is representative of the strain deformation of the drill collar 200.
In certain circumstances, the BHA 18 may be subject to bending strains, some of which may drive the BHA 18 to travel in an undesirable direction while forming the wellbore 12 or which may weaken or fatigue the BHA 18. Thus, a strain gauge (e.g., a foil strain gauge, a fiberoptic strain gauge, a piezoresistor strain gauge, a Micro-Opto-Electro-Mechanical Systems (MOEMS) strain gauge, a vibrating wire strain gauge, a capacitive strain gauge, and so forth) may be used to determine the bending strain undergone by the BHA 18. As an overview, each strain gauge may include an electrical circuit through which a current having an associated voltage may travel. The electrical circuit may include a resistance that correlates with a length of the strain gauge. By way of example, increasing the length of the strain gauge may increase the resistance of the strain gauge, and decreasing the length of the strain gauge may decrease the resistance of the strain gauge. The resistance may be provided by a conductor or resistor, and may be determined, for instance, by applying a voltage through the electrical circuit, sensing a voltage that has traveled the electrical circuit, and determining the difference between the applied voltage and the sensed voltage.
A strain gauge may determine a change of the resistance of a resistor or of the full strain gauge in which the change of the resistance is correlated with a change of the length of the strain gauge (i.e., a strain deformation). In some embodiments, the strain gauge may provide signals or feedback indicative of the resistance, and another component (e.g., a controller) may receive the signal and use the resistance to determine a change in length of the strain gauge and a corresponding strain deformation of the strain gauge. In additional or alternative embodiments, the strain gauge may provide signals or feedback directly indicative of the strain deformation. As an example, the strain gauge may be attached to a component. The component may undergo a strain deformation that changes a length of the component, and the strain deformation may change the length of the strain gauge, thereby changing the resistance of the strain gauge. The strain gauge may then transmit a signal indicative of the change in resistance associated with a strain deformation of the strain gauge. In still other embodiments, the strain gauge may record strain deformation measurements, resistance changes, or the like either in local storage media, or by transmitting the data to another component which stores the information.
A strain gauge 230 may facilitate determining a strain deformation of the chassis 204 or the flow diverter 206 as transmitted from a strain deformation of the drill collar 200. In some embodiments, the BHA 18 may include one or more seals 232 (e.g., O-rings, square rings, T-rings, I-rings, X-rings, Q-rings, etc.) that surround the flow diverter 206. The seals 232 may abut both the flow diverter 206 and the drill collar 200 to increase friction between the flow diverter 206 and the drill collar 200. For example, a first side (e.g., upstream side) of one of the seals 232 may be of high pressure (e.g., in contact with high pressure fluid), and a second side of the seals 232 may be of low pressure. Furthermore, the flow diverter 206 experience high pressure as well (e.g., be filled with the high-pressure fluid). The pressure differential between the flow diverter 206 and the low pressure at the second side of the seal 232 may cause the flow diverter 206 to radially expand, thereby pushing the outer surface of the seals 232 against the inner surface of the drill collar 200. The amount of force imparted to push the seals 232 radially against the drill collar 200 may be based on various parameters, such as a length of the flow diverter 206, a gap between the flow diverter 206 and the drill collar 200, a thickness of the flow diverter 206, and so forth, to control the restriction of dynamic movement between the flow diverter 206 and the drill collar 200. In this manner, the seals 232 facilitate restricting axial movement (e.g., sliding) between the flow diverter 206 and the drill collar 200, and the strain deformations of the drill collar 200 may be directly transmitted to the chassis 204 and/or flow diverter 206 and determined using the strain gauge 230. As such, in some embodiments, the strain gauge 230 may facilitate determining the strain deformations associated with the drill collar 200.
In the illustrated flow diverter 206, the strain gauge 230 is attached to the flow diverter 206 within a chamber 234 radially between an outer surface of the flow diverter 206 and an inner surface of the drill collar 200. Accordingly, in this embodiment, the flow diverter 206 acts as a chassis for the strain gauge 230. The chamber 234 may be filled with a fluid (e.g., oil) that may increase the pressure between the drill collar 200 and the flow diverter 206, and the strain gauge 230 may be within a pocket, cavity, or recess of the chamber 234. The pressure from the fluid may balance the pressure exerted by the drilling fluid 40 flowing through the flow diverter 206, thereby restricting deformation of the flow diverter 206 caused by the flow of the drilling fluid 40, and the recess of the chamber 234 is optionally sealed to cover the strain gauge 230, thereby shielding the strain gauge 230 from the fluid. In some embodiments, there may be components (e.g., a piston, a bellows, a diaphragm) configured to transmit pressure between the drilling fluid 40 and the fluid within the chamber 234 to balance the pressure between the chamber 234 and within the flow diverter 206, or to otherwise reduce strain deformation of the flow diverter 206 caused by a pressure differential between the chamber 234 and within the flow diverter 206.
In at least the embodiments in which the flow diverter 206 is in a near-bit position, the strain deformations determined using the strain gauge 230 may be extrapolated or otherwise used in some embodiments to determine a position of the drill bit 20. The BHA 18 may then be controlled to direct the drill bit 20 based on the position. For instance, the strain gauge 230 may be communicatively coupled to a first electronics board 236 (e.g., a first control board) within the chassis 204, such as via physical wiring routed through the flow diverter 206. The first electronics board 236—which may include a controller or processor—may receive signals (e.g., resistance readings of the strain gauge 230) indicative of strain undergone by the strain gauge 230, determine strain deformation undergone by the strain gauge 230 based on the signals, determine or estimate a position or orientation of the drill bit 20 based on the strain deformation (e.g., based on determining or inferring the bending experienced by the drill collar 200), and operate the BHA 18 based on the determined position of the drill bit 20 or drill collar 200. Additionally or alternatively, the first electronics board 236 may receive signals indicative of strain and store information regarding the strain for further analysis (e.g., determining strain deformations of various operations to, for instance, improve future designs or operation modeling).
The flow diverter 206 may include a cavity 262 in which other components (e.g., a second electronics or control board 264) may be located, and the flow diverter 206 may direct the drilling fluid 40 around the cavity 262 toward the drill bit 20. The strain gauge 260 may be attached to the flow diverter 206 in another chamber 234, which may be filled with a fluid to optionally reduce the pressure differential between the chamber 234 and the flow channel within the flow diverter 206, and to reduce strain deformation caused by the pressure differential.
The BHA 18 may further include the seals 232 that facilitate increasing the friction between the flow diverter 206 and the drill collar 200, thereby further enabling the strain deformation of the drill collar 200 to transmit to the flow diverter 206, and vice versa. In the illustrated embodiment, the strain gauge 260 may be communicatively coupled to a second electronics board 264 within the flow diverter 206, such as via physical wires routed through the flow diverter 206. Such wires may also be routed through a sleeve 266 of the BHA 18, which sleeve 266 is optionally a chassis for the flow diverter 206, or is a tubular element. Additionally or alternatively, the strain gauge 260 may be wirelessly coupled to the second electronics board 264. In further embodiments, the strain gauge 260 may be coupled to another electronics board, such as the first electronics board 236 in the chassis 204 of
In some tool designs and environments, certain strains of the drill collar 200 may not directly or proportionately transmit to the chassis 204. For instance, this may occur where the drill collar 200 may move axially or radially relative to the chassis. The radial gap between the outer surface of the centralizers 292 and the inner surface of the drill collar 200, as well as the radial gap between the centralizers 292 and a pressure housing 294 (see
In certain embodiments, it is not be desirable place a strain gauge on certain components of the BHA 18. For instance, the strain gauge may be attached to the BHA 18 in a controlled environment by trained personnel to enable the strain gauge to accurately determine strain deformations of the BHA 18. Some existing components, however, such as the chassis 204 and the drill collar 200, may be manufactured or assembled at a different location separate from the controlled environment. Thus, to attach some strain gauges to an existing component of the BHA 18, it may be desirable that the existing component be transported to a controlled environment or an additional manufacturing process be performed to enable the strain gauge 290 to determine strain deformations of the existing component. Such additional operations can increase time or cost to implement the strain gauge.
Some embodiments therefore include installing an additional component on the BHA 18, on which an alternative sensor is attached to determine a strain deformation of the additional component. The additional component may then be attached to an existing component of the BHA 18, and the reading of the strain deformation of the additional component may be associated with the strain deformation of the existing component, the drill collar, and the BHA 18, without having to install the strain gauge directly on the BHA 18. In other words, attaching the alternative sensor to the additional, separate component and attaching the additional component to existing components may be easier, more cost effective, and more convenient than attaching a strain gauge directly onto an existing component. The alternative sensor may then be communicatively coupled to the data processing system 160, to the first electronics board 236, to a data storage device, or to any suitable component that may control the operation of the BHA 18, or store strain deformation information based on the reading of the alternative sensor.
As an example,
It should be noted that for the illustrated embodiment, the first rod 330 and the strain gauge 334 may be assembled together in a process that is separate from the manufacturing process of the chassis 204 to the BHA 18. For example, the first rod 330 and the strain gauge 334 may be attached to one another in a controlled environment to enable the strain gauge 334 to facilitate determining strain deformations of the first rod 330 accurately, and the first rod 330 that then includes the strain gauge 334 may then be attached to the chassis 204 in a separate environment or process. In this manner, the chassis 204 does not have to be at the same the controlled environment to install the strain gauge 334 within the BHA 18, thereby reducing a cost to manufacture and assemble the BHA 18 having the strain gauge 334.
For example,
The techniques described with reference to
Multiple strain gauges 432 may be attached to the electronics board 430 to determine the strain deformations of the electronics board 430. The strain gauges 432 may include one or more different types of strain gauges, each different type providing a reading associated with a particular type of strain deformation of the electronics board 430. In some cases, the electronics board 430 may already be an existing component of the BHA 18 and may be used to control or monitor certain components of the BHA 18 or wellbore. In this way, attaching the strain gauges 432 directly onto the electronics board 430 may install the strain gauges 432 into the BHA 18 without having to utilize additional components, thereby limiting a cost to manufacture the BHA 18. In additional or alternative embodiments, multiple strain gauges 432 may be attached to an additional component such as a plate 434, instead of directly to the electronics board 430. The plate 434 may be coupled to or formed in the chassis 204 or the drill collar 200 via a fastener, a weld, an adhesive, another suitable component, or integral manufacturing, that enables the strain deformation of the drill collar 200 to transmit to the plate 434. By coupling the strain gauges 432 to the plate 434 instead of the electronics board 430, the strain gauges 432 may be easily attached to or removed from the BHA 18 even without removal of the electronics board 430 (e.g., to replace the strain gauges 432). A plate 434 may also be removable to allow removal of the strain gauges 432.
As used herein, the term “plate” is intended to cover any of a variety of different surfaces to which the strain gauges 432 may be coupled, and which are distinct from the collar enclosing an internal assembly. A plate is not limited to having planar surfaces; however, a plate of the present disclosure that is curved will generally have a radius of curvature that is at least 2, 3, 5, 10, 15, or 20 times greater than the radius of curvature of the collar or chassis to which it is attached. For instance, a chassis having an 8 in. (0.2 m) diameter and a 4 in. (0.1 m) radius may have a plate therein or thereon which is generally flat, or which has a radius of curvature of 10 in. (0.25 m) or more, 20 in. (0.5 m) or more, or 50 in. (1.3 m) or more. Additionally, even where three-dimensional or otherwise contoured in shape, a plate of the present disclosure will provide opposing surfaces that are generally parallel. In general, an annular component with a flow path therethrough would not be considered a plate for purposes of this disclosure.
Additionally, in-plane bending strain gauges 456 (including strain gauges 456A and 456B) may be on the first surface 446 of the electronics board 430. In the illustrated embodiment, a first in-plane bending strain gauge 456A is on one side 451 of the centerline 453, and a second in-plane bending strain gauge 456B is on the other side 455 of the centerline 453 and aligned with the first in-plane bending strain gauge 456A along a lateral axis 457 perpendicular to the centerline 453. The in-plane bending strain gauges 456 may be collectively used to determine a presence of bending the electronics board 430 about a vertical axis 458 (i.e., in-plane bending visible from a top view of the first surface 446). For instance, bending the electronics board 430 in a first bending direction 460 may shorten the first in-plane bending strain gauge 456A and may elongate the second in-plane bending strain gauge 456B, thereby changing (e.g., decreasing) the resistance reading of the first in-plane bending strain gauge 456A and changing (e.g., increasing) the resistance reading of the second in-plane bending strain gauge 456B. In this manner, the resistance readings of the in-plane bending strain gauges 456 relative to one another may be used to determine if the electronics board 430 is undergoing in-plane bending. The in-plane bending strain gauges 456 may not be substantially affected by other strain deformations of the electronics board 430, as other forms of strain deformations would affect geometric changes of the in-plane bending strain gauges 456 equally and, therefore, do not change resistance readings of the two in-plane bending strain gauges 456A, 456B relative to one another.
Further, a first out-of-plane bending strain gauge 462A and a first axial strain gauge 464A may also be on the first surface 446. In the illustrated embodiment, both the first out-of-plane bending strain gauge 462A and the first axial strain gauge 464A are positioned along the centerline 453. The first out-of-plane bending strain gauge 462A may be used to facilitate determining if the electronics board 430 is undergoing out-of-plane bending or bending about the lateral axis 457 (and viewable from the side surface 447 extending the length of the electronics board 430). The first axial strain gauge 464A may be used to facilitate determining if the electronics board 430 is undergoing tensile (e.g., elongation) forces or compressive (e.g., shortening) forces along the longitudinal axis 454. Such techniques will be further described herein, including with respect to
A second axial strain gauge 464B may also be along the centerline 453 on the second surface 490 and aligned with the first axial strain gauge 464A along the vertical axis 458. The resistance reading of each of the axial strain gauges 464 may be used to determine a tensile/compressive strain deformation of the electronics board 430 along the longitudinal axis 454 and along the lateral axis 457. For instance, tensile forces imparted on the electronics board 430 may elongate the electronics board 430 in first axial directions 494 along the longitudinal axis 454 and, due to the Poisson-effect, the tensile forces may also shorten the electronics board 430 in second axial directions 496 along the lateral axis 457. That is, as the stretches along the longitudinal axis 454, the electronics board 430 may become thinner along the lateral axis 457, as material is pulled from the lateral axis 457 to along the longitudinal axis 454. The resistance readings of both of the axial strain gauges 464 may be indicative of the elongation of the electronics board 430 in the first axial directions 494 and the shortening of the electronics board 430 in the second axial directions 496, and the resistance readings may be associated with the tensile forces. Furthermore, by placing the first axial strain gauge 464A on the first surface 446 and the second axial strain gauge 464B on the second surface 490, other strain deformations of the electronics board 430 do not substantially affect the resistance readings of the axial strain gauges 464. By way of example, out-of-plane bending of the electronics board 430 in the second bending direction 492 may increase the resistance reading of the second axial strain gauge 464B and may also decrease the resistance reading of the first axial strain gauge 464A. The respective change in resistances may cancel one another out, such that the overall resistance readings of the axial strain gauges 464 are not affected by out-of-plane bending of the electronics board 430. The axial strain gauges 464 can also be unaffected by torsional and in-plane bending. Thus, strain gauges of the present disclosure can be connected with bridge circuitry so that each set of strain gauges response selectively to a specific direction or type of deformation, and is less or not at all sensitive to deformations in other directions.
In some embodiments, further sensors may be included on the electronics board 430. For example, the electronics board 430 may include sensors that determine strains caused by vibration of the electronics board 430 relative to the chassis 204, or which simply measure vibration. Such sensors may be responsive to movement of the electronics board 430 above a particular frequency (e.g., above 2.5 kHz, above 5 kHz, etc.). It should also be noted that other deformations of the electronics board 430 may not affect the strain deformation readings of the strain gauges 452, 456, 462, 464. As an example, temperature elevations may elongate the electronics board 430 in each direction to change the resistances of the strain gauges 452, 456, 462, 464 in a manner as not to affect the respective readings of the torsion, in-plane bending, out-of-plane bending, or axial strains. That is, temperature changes may affect a change in the material fibers of each strain gauge 452, 456, 462, 464 equally and does not change relative resistance readings that would indicate a strain deformation. For example, for the axial strain gauge 464, an increase in temperature may cause the electronics board 430 to elongate along the longitudinal axis 454 and along the lateral axis 457. The percentage of elongation of the first surface 446 of the electronics board 430 along the longitudinal axis 454 may be substantially equal to the percentage of elongation of the second surface 490 of the electronics board 430 along the longitudinal axis 454, and the percentage of elongation of the first surface 446 along the lateral axis 457 may be substantially equal to the percentage of elongation of the second surface 490 along the lateral axis 457. As such, there is no substantial difference in resistance readings between the axial strain gauges 464, thereby indicating there is no strain deformation caused by temperature changes. Thus, the signals or feedback provided by the strain gauges 452, 456, 462, 464 accurately represent the particular strain deformation of interest and are temperature compensated.
In additional or alternative embodiments, the strain gauges 452, 456, 462, 464 may be used to monitor a condition of the electronics board 430. That is, the readings of the strain deformations may be used to determine a structural integrity of the electronics board 430, such as a fatigue of solder joints or circuit traces associated with the electronics board 430. By way of example, the determined strain deformations of the electronics board 430 may be used to determine strain loads imparted onto the electronics board 430 or whether the electronics board 430 may be used for the operation of the BHA 18 or is to be replaced. In another example, the strain deformations may be used to determine how to improve the design of the electronics board 430 or to implement the electronics board 430 in a position that would limit the imparted strain deformations. For instance, loads imparted onto the electronics board 430 during operation of the drilling system 10 (e.g., by engagement of a drill bit or drill collar with the geological formations 14) may cause the electronics board 430 to deform. The strain deformations of the electronics board 430 may be used to determine manners to limit the forces imparted onto the electronics board 430 (e.g., attaching the electronics board 430 at a different location, implementing a protection system). For example, the electronics board 430 may store information regarding the strain deformation, and the information may be analyzed during a drilling operation or post-operation to determine the effects of the operation of the drilling system 10 on the electronics board 430.
It should be noted that different strain gauges may be used in addition to or as an alternative to the strain gauges 452, 456, 462, 464 to determine the aforementioned strain deformations or to determine other types of strain deformations. Indeed, the layout of the strain gauges strain gauges 452, 456, 462, 464 may be modified in any suitable manner to determine any particular type of strain deformation of interest. Furthermore, the strain gauges 452, 456, 462, 464 may be implemented along different lengths or sections of the BHA 18. As such, the strain deformations of different sections of the BHA 18 may be determined, so as to determine a more accurate orientation of the BHA 18 at any given moment. Moreover, although the strain gauges 452, 456, 462, 464 are depicted as foil strain gauges in the illustrated embodiment, the strain gauges 452, 456, 462, 464 may additionally or alternatively be any other suitable type of strain gauge.
The plate 552 may be made of a material, such as a metal, metal alloy, or polymer having a low stiffness (i.e., a more elastic material) or having a thinner cross-section to enable movement of the chassis 204 to cause the plate 552 to move easily, thereby restricting other movement of the plate 552 relative to the chassis 204 (e.g., due to slip). In other words, the chassis 204 transfers strains more easily to the plate 552 without having to impart significant attachment forces to couple the plate 552 onto the chassis 204 together. Thus, the strains of the plate 552 correspond more accurately to the strains of the chassis 204. Furthermore, the plate 552 may be made of a material having a similar coefficient of thermal expansion as that of the chassis 204, such that changes in temperature do not cause the plate 552 to move relative to the chassis 204.
It should be noted that in some embodiments the plate 552 may be easily coupled to and decoupled from the chassis 204 (e.g., by unfastening or removing the fasteners 554). In some embodiments, the assembly of the strain gauge 550 and the plate 552 may be implemented and removed from the BHA 18 without moving the BHA to a controlled environment. As an example, the strain gauge 550 and the plate 552 may be easily removed from the BHA 18 and then reattached to the BHA 18, such as during maintenance, during replacement of components of BHA 18, or even at the wellsite. As another example, the strain gauge 550 and the plate 552 may be coupled to any existing BHA 18, such as to retrofit onto an existing chassis 204. In this way, the plate 552 provides greater flexibility to implement the strain gauge 550 onto a particular BHA 18.
In some embodiments, the plate 552 may be formed into a particular shape that enables the plate 552 to be more responsive to particular strain deformations and avoid being affected by other strain deformations. For example,
The geometry of the flexure plate 580 may readily enable torsional deformation of the chassis 204 to transmit to the flexure plate 580. By way of example, torsional deformation of the chassis 204 can concentrate into the arms 586 and change the respective resistances of the strain gauges 550. In some embodiments, the readings of the strain gauges 550 are compared to one another to determine the torsional strain of the flexure plate 580 and of the chassis 204. For instance, the first mounting surface 582A may twist in a first rotational direction 588 and the second mounting surface 582B may twist in a second rotational direction 590 opposite the first rotational direction 588. As a result, a first arm 586A may elongate and a second arm 586B may shorten, thereby changing (e.g., increasing) a resistance reading of a first strain gauge 550A on the first arm 586A and changing (e.g., decreasing) a resistance reading of a second strain gauge 550B on the second arm 586B. The discrepancy of resistance readings between the strain gauges 550 may be used to determine the torsion of the flexure plate 580 and of the BHA 18.
The geometry of the flexure plate 580 and the placement of the strain gauges 550 on the flexure plate 580 may avoid or restrict other strain deformations from interfering with the torsional strain determinations. More particularly, out-of-plane bending, in-plane bending, or axial strains may not affect the resistance readings of the strain gauges 550 relative to one another, and such strain deformations may not be determined via the strain gauges 550. In this way, any change in the relative resistance readings of the strain gauges 550 may be a result of a torsional strain of the flexure plate 580, with minimal or no sensitivity to other types of strain.
The cross plate 610 may enable torsional strain to be more directly transmitted onto the center section 614 to be determined by the strain gauge 550 and to provide a uniform strain field to measure the torsional strain. It should be noted that in some cases, the attachment between any plate with a component of the BHA 18 may affect a torsional strain reading associated with the plate. For example, there may be movement at the coupling points (e.g., fasteners) between a rectangular shaped plate 552 and a component of the BHA 18 during torsion of the component, such as because the plate 552 has resistance to twisting. Such movement may limit an amount of torsional strain transferred to the plate 552 and determined by the strain gauge 550, thereby affecting an accuracy of the torsional strain reading made by the strain gauge 550 to represent the torsional strain of the component. The movement may be factored into the torsional strain reading (e.g., the torsional strain reading may be calibrated or corrected based on the movement), or the movement may be restricted by adding adhesives, implementing a locking component, or other additional assembly steps. However, since the cross plate 610 enables torsional strain to be transmitted more effectively from the component onto the cross plate 610, there may be less movement at the coupling points between the cross plate 610 and the component. As a result, the torsional strain reading made by the strain gauge 550 may accurately represent the torsion of the component of the BHA 18 without having to perform the additional assembly steps.
Although
For the plate 752, bending measurements may be made along multiple bending axes, such x-axis 769 and the vertical axis 771. Bending around each axis can be measured using four strain gauges. For instance, to measure bending around the x-axis 769, four strain gauges 750A-750D may be used. As shown, the strain gauges 750A, 750B are mounted on an upper surface of the sidewalls 761. Additional strain gauges 750C, 750D may be mounted on a bottom surface of the sidewalls 761, or on another parallel surface. For instance, in
The strain gauges 750E-750H may be used in an analogous manner for measuring bending about the vertical axis 771. In particular, strain gauges 750E, 750F may be located on inner surfaces of the sidewall 761, above the cutout, while strain gauges 750G, 750H may be located on inner surfaces of the sidewall 761, below the cutout. Due to such poisoning, strain gauges 750F and 750H are not visible in
The plate 752 (and the corresponding strain gauges 750A-750H and sensing circuits) is selectively responsible to the respective bending, with no or negligible amounts of cross-talk on output for bending about another axis. Thus, bending about the x-axis 769 has little or no cross-talk from bending about the vertical axis 771, and bending about the z-axis 771 likewise has little or no cross-talk from bending about the x-axis 769. Further, the described sensing circuits can compensate for any changes in ambient temperature and minimize mechanical cross-talk from other strains that are induced. Such other strains may be created by, for instance, changes in weight-on-bit (whether axial tension or compression), and those due to torsion. This can be the case as those forces produce either equal or negligibly small changes to the sidewalls 761, thereby leaving the bridge circuit balance unaffected.
The plate 752 may also be used to provide a stacked or nested structure similar to that described with respect to
The plate 752 may be used to detect torsional strain (e.g., to determine torque on the plate 752, and ultimately on the drill collar 200), which is optionally done in combination with determining of bending (e.g., along x-axis 769 or the vertical axis 771).
The cross-shaped section 710 may be used in a manner similar to that of the cross plate 610 of
The plate 752 is illustrative only, and may be varied in any number of manners, and may also be made of any suitable material. For instance, the plate 752 may be formed of a metal, metal alloy, composite, organic, or polymer material, or combinations thereof. The plate 752 may also be formed in any suitable manner. For instance, the plate 752 may be machined, cast/molded, additively manufactured, or produced in any other suitable manner. The shape may also be varied as desired, such as by modifying the shape of the cross-shaped section, the sidewalls, the posts, and the like. The dimensions may be varied as well to provide greater or lesser separation between strain gauges in the same bridge, and strain gauges may be used to measure any suitable strain, and are not limited to in-plane bending, out-of-plane bending, axial strain, or torsional strain.
At block 844, the data processing system 160 operates the drilling system 10 based on the feedback received from the sensor 167. For example, the feedback (e.g., an out-of-plane bending strain is above a threshold strain) may indicate that the BHA 18 is likely directing the drill bit 20 in a path that is off the desired well path and is instead drilling the wellbore 12 toward a projected location that is away from a target location. As a result, a particular operation of the drilling system 10, such as rotational speed or WOB of the drill bit 20, may be adjusted to change the bending and drive the BHA 18 toward the target location (e.g., upon determining that the projected location is different than the target location by a threshold distance). In another example, the feedback may indicate that an undesirable force is imparted onto the BHA 18 and may affect a performance of the BHA 18 (e.g., the quality of the wellbore 12) or the structural integrity or other health of the BHA 18. Therefore, the operation of the drilling system 10 may be adjusted to reduce or limit the effects of the undesirable force.
With reference to the embodiments described herein, and in an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be noted that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be noted that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Further, lists of alternative features or aspects joined by “or” are intended to indicate that one or more of such features or aspects can be included, and not that such features are purely alternatives.
While embodiments of the present disclosure have been discussed primarily with reference to downhole drilling operations for extracting hydrocarbons, embodiments of the present disclosure are not related to any particular environment, industry, or application. For instance, drilling technologies to form wellbores to set utility lines are also applicable for embodiments of the present disclosure. Further, any industry or application in which measurements of strain may affect performance of operation of equipment may utilize aspects of the present disclosure, including in automotive, aerospace, construction, manufacturing, mining, and alternative energy industries and applications.
The specific embodiments described herein have been shown by way of example, and it should be noted that these embodiments may be susceptible to various modifications and alternative forms. It should be further noted that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.
The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted as functional claim elements. However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted as functional claim elements.
This application claims the benefit of, and priority to U.S. Patent Application No. 62/880,918, filed Jul. 31, 2019 and titled “Indirect Detection of Bending of a Collar,” and is related to U.S. Patent Application No. 62/880,997, filed Jul. 31, 2019 and titled “Strain Gauges for Detecting Strain Deformations of a Plate.” Each of the foregoing is expressly incorporated herein by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 62880918 | Jul 2019 | US |
