LOCK MONITORING SYSTEM FOR HANGER

BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

In order to meet consumer and industrial demand for natural resources, companies search for and extract oil, natural gas, and other subterranean resources from the earth. Once a desired subterranean resource is discovered, drilling and production systems are employed to access and extract the desired subterranean resource. The drilling and production systems may be located onshore or offshore depending on the location of the desired subterranean resource. In some drilling and production systems, a hanger may be used to suspend a string (e.g., piping for a flow in and/or out of a well). The hanger may be disposed within a spool of a wellhead, which supports both the hanger and the string. For example, a tubing hanger may be lowered into a tubing spool by a tubing hanger running tool (THRT). Once the tubing hanger has been lowered into a landed position in the tubing spool, the tubing hanger may be locked into a locked position in the tubing spool. Then, the THRT may be uncoupled from the tubing hanger and removed from the wellhead.

BRIEF DESCRIPTION

In one embodiment, a monitoring system includes one or more sensors coupled to a hanger running assembly that is configured to be inserted into a housing. The one or more sensors are configured to output sensor signals indicative of a respective distance between opposed ends of a lock ring of the hanger running assembly. The monitoring system also includes one or more processors configured to determine a condition of the lock ring based on the sensor signals.

In one embodiment, a monitoring system includes a hanger running tool configured to couple to a hanger with a lock ring. The monitoring system includes one or more sensors coupled to the hanger running tool, and the one or more sensors are configured to output sensor signals indicative of a respective distance between opposed ends of the lock ring. The monitoring system also includes one or more processors configured to determine a condition of the lock ring based on the sensor signals.

In one embodiment, a method of operating a monitoring system includes receiving, at one or more processors, sensor signals from one or more sensors coupled to a hanger running assembly. The method also includes determining, using the one or more processors, a respective distance between opposed ends of a lock ring of the hanger running assembly based on the sensor signals. The method also includes determining, using the one or more processors, the condition of the lock ring based on the respective distance. The method further includes providing, using the one or more processors, an output to indicate the condition of the lock ring.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of a resource extraction system, in accordance with an embodiment of the present disclosure;

FIG. 2 is a side cross-sectional view of a lock monitoring system that may be used with the resource extraction system of FIG. 1, in accordance with an embodiment of the present disclosure;

FIG. 3 is a side cross-sectional view of a sensor of the lock monitoring system of FIG. 2, wherein the sensor is coupled to a tubing hanger running tool (THRT) that is used to run a hanger and a lock ring has a compressed condition, in accordance with an embodiment of the present disclosure;

FIG. 4 is a side cross-section view of the sensor of the lock monitoring system of FIG. 2, wherein the sensor is coupled to the THRT that is used to run the hanger and the lock ring has an expanded condition, in accordance with an embodiment of the present disclosure;

FIG. 5 is a side cross-sectional view of the sensor of the lock monitoring system of FIG. 2 coupled to the THRT that is used to run the hanger, in accordance with an embodiment of the present disclosure;

FIG. 6 is perspective view of the sensor of the lock monitoring system of FIG. 2 coupled to the THRT that is used to run the hanger, in accordance with an embodiment of the present disclosure;

FIG. 7 is a perspective cross-sectional view of the sensor of the lock monitoring system of FIG. 2 coupled to the THRT that is used to run the hanger, in accordance with an embodiment of the present disclosure;

FIG. 8 is a top view of sensors of the lock monitoring system of FIG. 2 coupled to the THRT that is used to run the hanger, in accordance with an embodiment of the present disclosure;

FIG. 9 illustrate exemplary graphs that may be generated based on data from the sensor(s) of the lock monitoring system of FIG. 2, in accordance with an embodiment of the present disclosure;

FIG. 10 is a schematic diagram of the lock monitoring system of FIG. 2 with additional sensors, in accordance with an embodiment of the present disclosure;

FIG. 11 is a side cross-sectional view of a portion of the lock monitoring system of FIG. 2, in accordance with an embodiment of the present disclosure;

FIG. 12 is a side cross-sectional view of the THRT that may be used as part of the lock monitoring system of FIG. 2, in accordance with an embodiment of the present disclosure;

FIG. 13 is an exploded cross-sectional view of the THRT that may be used as part of the lock monitoring system of FIG. 2, in accordance with an embodiment of the present disclosure;

FIG. 14 is an example of a graphical user interface that may be generated via the lock monitoring system of FIG. 2, in accordance with an embodiment of the present disclosure;

FIG. 15 is a side cross-sectional view of a sensor of a lock monitoring system that may be used with the resource extraction system of FIG. 1, wherein the sensor is coupled to a hanger, in accordance with an embodiment of the present disclosure;

FIG. 16 is a top view of the sensor of the lock monitoring system of FIG. 15, wherein a lock ring is in a compressed condition, in accordance with an embodiment of the present disclosure;

FIG. 17 is a top view of the sensor of the lock monitoring system of FIG. 15, wherein the lock ring is in an expanded condition, in accordance with an embodiment of the present disclosure;

FIG. 18 is a top view of a sensor of a lock monitoring system that may be used with the resource extraction system of FIG. 1, wherein the sensor is coupled to a lock ring, in accordance with an embodiment of the present disclosure;

FIG. 19 is a side view of the sensor of FIG. 15 coupled to the lock ring, in accordance with an embodiment of the present disclosure;

FIG. 20 is a side cross-sectional view of the sensor of FIG. 15 coupled to the lock ring as part of the lock monitoring system, in accordance with an embodiment of the present disclosure;

FIG. 21 is a flow diagram of a method of operating a lock monitoring system, in accordance with an embodiment of the present disclosure; and

FIG. 22 is an example of graphs that represent communication of data via modulation of acoustic signals, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated 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 appreciated 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,” “the,” and “said” 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. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments.

FIG. 1 is a block diagram of an embodiment of a resource extraction system 10. The resource extraction system 10 may be configured to extract various minerals and natural resources, including hydrocarbons (e.g., oil and/or natural gas), from the earth. Additionally or alternatively, the resource extraction system 10 may be configured to inject substances into the earth. The resource extraction system 10 may be land-based (e.g., a surface system) or subsea (e.g., a subsea system). As shown, the resource extraction system 10 includes a wellhead 12 coupled to a mineral deposit 14 via a well 16. The well 16 includes a wellhead hub 18 and a wellbore 20. The wellhead hub 18 may include a large diameter hub that is disposed at the termination of the wellbore 20. The wellhead hub 18 provides for the connection of the wellhead 12 to the well 16.

The wellhead 12 includes multiple components that control and regulate activities and conditions associated with the well 16. For example, the wellhead 12 may include bodies, valves, and seals that route produced minerals from the mineral deposit 14, provide for regulating pressure in the well 16, and/or provide for the injection of chemicals into the wellbore 20. In the illustrated embodiment, the wellhead 12 includes a tree 22, a tubing spool 24 (e.g., housing), a casing spool 26 (e.g., housing), and a tubing hanger 28 (e.g., insert). The resource extraction system 10 may include other device(s) that are coupled to the wellhead 12 and/or that are used to assemble and/or control various components of the wellhead 12. For example, in the illustrated embodiment, the resource extraction system 10 includes a tubing hanger running tool (THRT) 30 suspended from a drilling string 32. During a running or lowering operation for the tubing hanger 28, the THRT 30 is coupled to the tubing hanger 28. The THRT 30 and the tubing hanger 28 are lowered (e.g., run) together into the wellhead 12. Once the tubing hanger 28 has been lowered into a landed position in the tubing spool 24, the tubing hanger 28 may be locked into a locked position in the tubing spool 24. Then, the THRT 30 may be uncoupled from the tubing hanger 28 and extracted from the wellhead 12 by the drilling string 32.

The tree 22 may include a variety of flow paths (e.g., bores), valves, fittings, and controls for operating the well 16. For instance, the tree 22 may include a frame that is disposed about a tree body, a flow-loop, actuators, and valves. Further, the tree 22 may be in fluid communication with the well 16. As illustrated, the tree 22 includes a tree bore 34. The tree bore 34 provides for completion and workover procedures, such as the insertion of tools into the wellhead 12, the injection of various chemicals into the well 16, and the like. Further, minerals extracted from the well 16 (e.g., oil and/or natural gas) may be regulated and routed via the tree 22. For instance, the tree 22 may be coupled to a jumper or a flowline that is tied back to other components, such as a manifold. Accordingly, produced minerals flow from the well 16 to the manifold via the tree 22 before being routed to shipping or storage facilities. A blowout preventer (BOP) 36 may also be included, either as a part of the tree 22 or as a separate device. The BOP 36 may include a variety of valves, fittings, and controls to block oil, gas, or other fluid from exiting the well in the event of an unintentional release of pressure or an overpressure condition. It should be appreciated that a lubricator may be utilized in place of the BOP 36.

The tubing spool 24 and the casing spool 26 provide a base for the tree 22. The tubing spool 24 has a tubing spool bore 38, and the casing spool 26 has a casing spool bore 40. The bores 38 and 40 connect (e.g., enable fluid communication between) the tree bore 34 and the well 16. Thus, the bores 38 and 40 may provide access to the wellbore 20 for various completion and workover procedures. For example, components may be run down to the wellhead 12 and disposed in the tubing spool bore 38 and/or the casing spool bore 40 to seal-off the wellbore 20, to inject chemicals downhole, to suspend tools downhole, to retrieve tools, and the like.

The wellbore 20 may contain elevated fluid pressures. For example, pressures within the wellbore 20 may exceed 10,000 pounds per square inch (PSI), 15,000 PSI, or 20,000 PSI. Accordingly, resource extraction systems 10 employ various mechanisms, such as mandrels, seals, plugs, and valves, to control and regulate the well 16. For example, the tubing hanger 28 may be disposed in the tubing spool 24 to secure tubing suspended in the wellbore 20 and to provide a path for hydraulic control fluid, chemical injection, electrical connection(s), and the like. The tubing hanger 28 includes a central bore 42 that extends through the center of a body 44 of the tubing hanger 28 and that is in fluid communication with the casing spool bore 40 and the wellbore 20. The central bore 42 is configured to facilitate flow of hydrocarbons through the body 44 of the tubing hanger 28.

As shown, a lock ring 46 (e.g., metal ring; c-shaped ring) may be coupled to the tubing hanger 28, such that the lock ring 46 is disposed between the tubing spool 24 and the tubing hanger 28. After the tubing hanger 28 reaches the landed position in the tubing spool 24, the lock ring 46 may be released (e.g., expanded; set) to cause the tubing hanger 28 to be in the locked position in the tubing spool 24. For example, rotation and/or withdrawal of the THRT 30 may enable the lock ring 46 to expand radially-outwardly from a compressed condition to an expanded condition to engage the tubing spool 24. Once the lock ring 46 is engaged with the tubing spool 24, the lock ring 46 may block withdrawal or extraction of the tubing hanger 28 from the tubing spool 24. To facilitate discussion, the resource extraction system 10 and its components may be described with reference to an axial axis or direction 50, a radial axis or direction 52, and a circumferential axis or direction 54. Additionally, the tubing hanger 28 and the lock ring 46 may together be considered to form an insert or a hanger assembly. Furthermore, the tubing hanger 28, the THRT 30, and the lock ring 46 may together be considered to form a hanger running assembly.

As discussed in detail herein, the resource extraction system 10 may include a lock monitoring system configured to determine that the tubing hanger 28 has reached the locked position in the tubing spool 24. In some embodiments, the lock monitoring system may be configured to provide real-time (e.g., substantially real-time, such as within seconds or minutes; during operations to install the tubing hanger 28 in the tubing spool 24) feedback regarding the position of the tubing hanger 28 in the tubing spool 24. For example, in response to determining that the tubing hanger 28 has reached the locked position, the lock monitoring system may provide an output (e.g., visible and/or audible output, such as an indicator on a display screen and/or an alarm from a speaker). In some embodiments, the lock monitoring system may determine the position of the tubing hanger 28 in the tubing spool 24 and provide the information about the position of the tubing hanger 28 in the tubing spool 24 without or prior to performing other tests (e.g., without or prior to performing a pressure test) on the wellhead 12.

In certain embodiments, the lock monitoring system includes one or more sensors that are configured to detect a condition (e.g., configuration; position) of the lock ring 46, such as whether the lock ring 46 is in the compressed condition and/or the expanded condition. The condition of the lock ring 46 indicates whether the lock ring 46 is engaged with the tubing spool 24, and thus, whether the tubing hanger 28 is in the locked position in the tubing spool 24. The one or more sensors may be coupled to the THRT 30, the lock ring 46, and/or the tubing hanger 28. The one or more sensors may include any suitable type(s) of sensor(s), including one or more displacement sensors. For example, the one or more sensors may include one or more non-contact displacement sensors, including potentiometers, eddy current sensors, and/or Hall effect sensors. As another example, the one or more sensors may include one or more draw-wire sensors. As discussed in more detail herein, the one or more sensors may detect the condition of the lock ring 46 via detection of a respective distance between the THRT 30 and the lock ring 46 and/or a respective distance between opposed ends of the lock ring 46. The lock monitoring system also includes a computing system that is communicatively coupled to the one or more sensors. For example, the computing system may include at least one controller, and the at least one controller is configured to receive signals (e.g., data) from the one or more sensors and process the signals to determine the position of the tubing hanger 28 in the tubing spool 24. The controller may also be configured to control the one or more sensors and/or to generate the output.

FIG. 2 is a side cross-sectional view of an embodiment of a lock monitoring system 60 for the tubing hanger 28. To facilitate discussion, a first side 62 of a central axis 64 illustrates the tubing hanger 28 in a landed position in the tubing spool 24 and a second side 66 of the central axis 64 illustrates the tubing hanger 28 in a locked position in the tubing spool 24. Additionally, FIG. 3 illustrates an embodiment of a portion of the tubing hanger 28 in the landed position in the tubing spool 24, and FIG. 4 illustrates an embodiment of a portion of the tubing hanger 28 in the locked position in the tubing spool 24.

As shown, in FIGS. 2-4, in the landed position, a first hanger surface 68 (e.g., radially-extending surface; axially-facing surface; lower surface) contacts a spool shoulder 70 (e.g., radially-extending surface; axially-facing surface). In particular, the first hanger surface 68 and the spool shoulder 70 overlap along the radial axis 52 (e.g., a respective outer diameter of the tubing hanger 28 across the first hanger surface 68 is greater than a respective inner diameter of the tubing spool bore 38 across the spool shoulder 70). Thus, the contact between the first hanger surface 68 and the spool shoulder 70 blocks the tubing hanger 28 from moving further downhole toward the well.

As shown, in the locked position, a first lock ring surface 72 (e.g., radially-extending surface; axially-facing surface; upper surface) contacts a spool surface 74 (e.g., radially-extending surface; axially-facing surface). In particular, the lock ring 46 may be configured to expand radially-outwardly from the compressed condition to the expanded condition upon withdrawal of the THRT 30. This expansion of the lock ring 46 may cause the first lock ring surface 72 and the spool surface 74 to overlap along the radial axis 52 (e.g., a respective outer diameter across the first lock ring surface 72 is greater than a respective inner diameter of the tubing spool bore 38 across the spool surface 74). Additionally, in the locked position, a second lock ring surface 76 (e.g., radially-extending surface; axially-facing surface; lower surface) contacts a second hanger surface 78 (e.g., radially-extending surface; axially-facing surface; upper surface). The second lock ring surface 76 and the second hanger surface 78 overlap along the radial axis 52 (e.g., a respective inner diameter across the second lock ring surface 76 is less than a respective outer diameter of the tubing hanger 28 across the second hanger surface 78). Thus, the contact between the first lock ring surface 72 and the spool surface 74, as well as the contact between the second lock ring surface 76 and the second hanger surface 78, block the tubing hanger 28 from moving upwardly away from the well.

To install the tubing hanger 28 in the tubing spool 24, the THRT 30 may be coupled to the tubing hanger 28 (e.g., via a threaded interface 80; via rotation in a first rotational direction about the central axis 64) and the lock ring 46. As shown on the first side 62 of the central axis 64 in FIG. 2 and in FIG. 3, the THRT 30 may contact a portion of the lock ring 46 to compress the lock ring 46. In particular, the THRT 30 may circumferentially surround and contact an extension portion 82 of the lock ring 46 to compress the lock ring 46 and to drive the lock ring 46 radially-inwardly toward the tubing hanger 28 (e.g., hold the lock ring 46 in the compressed condition).

Then, the THRT 30 and the tubing hanger 28 with the lock ring 46 may be lowered together toward the tubing spool 24. The THRT 30 and the tubing hanger 28 with the lock ring 46 may be lowered together until the first hanger surface 68 contacts the spool shoulder 70, thus reaching the landed position in the tubing spool 24. Then, after reaching the landed position in the tubing spool 24, the THRT 30 may be rotated relative to the tubing hanger 28 to cause the THRT 30 to move axially relative to the tubing hanger 28 and the lock ring 46 (e.g., via the threaded interface 80; via rotation in a second direction rotation about the central axis 64). In particular, as shown on the second side 66 of the central axis 64 in FIG. 2 and in FIG. 4, the THRT 30 may be rotated relative to the tubing hanger 28 to cause the THRT 30 to move axially to adjust and to eventually remove the contact between the THRT 30 and the lock ring 46. This enables the lock ring 46 to expand radially-outwardly toward the tubing spool 24 into the expanded condition to thereby cause the tubing hanger 28 to reach the locked position in the tubing spool 24. The THRT 30 may continue to be rotated relative to the tubing hanger 28 to cause the THRT 30 to separate from the tubing hanger 28 so that the THRT 30 can then be withdrawn, while the tubing hanger 28 with the lock ring 46 remains in the locked position in the tubing spool 24.

The lock monitoring system 60 is configured to determine that the tubing hanger 28 has reached the locked position in the tubing spool 24. To accomplish this, the lock monitoring system 60 includes one or more sensors that are configured to detect the condition of the lock ring 46, such as whether the lock ring 46 is in the compressed condition and/or the expanded condition. As noted herein, the condition of the lock ring 46 indicates whether the lock ring 46 is engaged with the tubing spool 24, and thus, whether the tubing hanger 28 is in the locked position in the tubing spool 24. The one or more sensors may detect the condition of the lock ring 46 via detection of the radial distance between the THRT 30 and the lock ring 46 and/or the circumferential distance between opposed ends of the lock ring 46. The one or more sensors may include any suitable type(s) of sensor(s) in any suitable location.

FIGS. 2-4 include the one or more sensors 84 coupled to the THRT 30. The one or more sensors 84 may be coupled to the THRT 30 via a fastener(s), a threaded connection, an adhesive connection, an interference fit, other suitable connection(s), or any combination thereof. In FIG. 2, the lock monitoring system 60 includes two sensors 84 that are diametrically opposed (e.g., on opposite sides of the THRT 30); however, it should be appreciated that any number of sensors 84 (e.g., distributed along the axial axis 50 and/or along the circumferential axis 54) may be utilized to detect the locking of the tubing hanger 28.

In operation, the one or more sensors 84 generate signals (e.g., data) that are indicative of the respective distance between the THRT 30 and the lock ring 46 and/or the respective distance between opposed ends of the lock ring 46. For example, as the THRT 30 rotates relative to the tubing hanger 28 and the lock ring 46, the THRT 30 moves axially relative to the tubing hanger 28 and the lock ring 46 (e.g., via the threaded interface 80; away from the well; from its position shown in FIG. 2 to its position shown in FIG. 3). Furthermore, as the THRT 30 moves axially relative to the tubing hanger 28 and the lock ring 46 (e.g., away from the well), the respective distance between the one or more sensors 84 in the THRT 30 and the lock ring 46 increases until eventually the THRT 30 entirely separates from (e.g., breaks contact with) the lock ring 46. Additionally, as the THRT 30 rotates relative to the tubing hanger 28 and the lock ring 46, the one or more sensors 84 travel circumferentially about the lock ring 46 and pass across a circumferential gap between opposed ends of the lock ring 46.

The one or more sensors 84 may provide the signals to a computing system 100. The computing system 100 may process and analyze the signals to determine whether the signals indicate that the tubing hanger 28 is in the locked position in the tubing spool 24. In particular, the computing system 100 may process and analyze the signals to determine the respective values (e.g., inductance; angle of rotation; distance(s)) as certain values may be known to correspond to full, proper locking of the tubing hanger 28 in the tubing spool 24. Thus, the computing system 100 may compare the respective values derived from the signals to stored values (e.g., stored respective thresholds) that correspond to the full, proper locking of the tubing hanger 28 in the tubing spool 24. Then, if the respective values derived from the signals exceed or match the stored values, the computing system 100 may determine that the signals indicate that the tubing hanger 28 is in the locked position in the tubing spool 24. Similarly, if the respective values derived from the signals do not exceed or match the stored values, the computing system 100 may determine that the signals indicate that the tubing hanger 28 is not in the locked position in the tubing spool 24.

In this way, the lock monitoring system 60 may identify complete locking operations with adequate, expected expansion of the lock ring 46 that sufficiently engages the tubing spool 24. Additionally, the lock monitoring system 60 may identify incomplete and/or failed locking operations with inadequate, unexpected expansion of the lock ring 46 that insufficiently engages the tubing spool 24. The incomplete and/or failed locking operations may occur for various reasons, such as insufficient rotation of the THRT 30, axial misalignment of the lock ring 46 and the tubing spool 24, and/or debris build up between the lock ring 46 and the tubing spool 24, for example. In some embodiments, the computing system 100 may generate an output. In some embodiments, the computing system 100 may communicate (e.g., via a network, such as a wireless network) the output to another system or device, such as a user device 102 (e.g., a mobile phone, a remote computing system) accessible to an operator (e.g., a human operator). The output may include the signals, an indication of the position of the tubing hanger 28, a visible alert, and/or audible alert.

In certain embodiments, the lock monitoring system 60 includes at least one actuator (e.g., electromechanical actuator, hydraulic actuator, pneumatic actuator). The actuator(s) may be configured to adjust the THRT 30, such as to drive rotation of the THRT 30 about the tubing hanger 28 and/or to lower/raise the THRT 30. The computing system 100 may be configured to control and/or provide outputs that cause control of the actuator(s). For example, in response to determining that the tubing hanger 28 is landed, the computing system 100 may automatically control and/or provide outputs that cause control of the actuator(s) to rotate the THRT 30 to release the lock ring 46. As another example, in response to determining that the tubing hanger 28 is adequately locked, the computing system 100 may automatically control and/or provide outputs that cause control of the actuator(s) to continue to rotate the THRT 30 to withdraw the THRT 30. As another example, in response to determining that the tubing hanger 28 is not adequately locked, the computing system 100 may automatically control and/or provide outputs that cause control of the actuator(s) to rotate the THRT 30 to compress the lock ring 46 to attempt to reset (e.g., clear debris between the lock ring 46 and the tubing spool 24).

In certain embodiments, the computing system 100 is an electronic computing system having electrical circuitry configured to determine the locking of the tubing hanger 28 based on signals from the one or more sensors 84. The computing system 100 may be a distributed computing system including components located at the wellhead and/or components remote from the wellhead. One or more processors may be used to execute software, such as software for determining the locking of the tubing hanger 28, and so forth. Moreover, the one or more processors may include multiple microprocessors, one or more “general-purpose” microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICs), or some combination thereof. For example, the one or more processors may include one or more reduced instruction set (RISC) processors. One or more memory devices may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The one or more memory devices may store a variety of information and may be used for various purposes. For example, the one or more memory devices may store processor-executable instructions (e.g., firmware or software) for the one or more processors to execute, such as instructions for determining the locking of the tubing hanger 28, and so forth. The one or more memory devices may include a storage device(s) (e.g., nonvolatile storage), such as ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The storage device(s) may store data, such as threshold(s) and/or look-up tables, for example. Any of the processors and/or memory devices disclosed herein may include such features.

It should be appreciated that the computing system 100 may include the one or more processors, the one or more memory devices, as well as any of a variety of additional components, such as a display screen, an input device (e.g., button, switch), a speaker, a light emitter, a communication device, or the like. The display screen may display information for visualization by the operator (e.g., a status of the tubing hanger 28, such as whether the tubing hanger 28 is landed and/or locked). The input device may enable the operator to provide inputs to the computing system 100. It should be appreciated that the display screen may be a touchscreen display, and thus, the display screen may also operate as the input device. When present, the speaker may output audible alarms, the light emitter may output light indicators, and the communication device may communicate with the user device 102 and/or other systems or devices. When present, the user device 102 includes a display screen that may display information for visualization by the operator (e.g., the status of the tubing hanger 28, such as whether the tubing hanger 28 is landed and/or locked). It should be appreciated that the computing system 100 and the user device 102 may enable output of information at the wellhead (e.g., via one display screen, the light emitter, the speaker) and remote from the wellhead (e.g., via another display screen of the user device 102 that is carried by the operator and/or in a remote monitoring station)

FIG. 5 is a side cross-sectional view of an embodiment of one of the one or more sensors 84 coupled to the THRT 30, and FIG. 6 is a bottom perspective view of an embodiment of one of the one or more sensors 84 coupled to the THRT 30. With reference to FIGS. 5 and 6, the THRT 30 includes a distal end 110 that circumferentially surrounds the extension portion 82 of the lock ring 46 to compress the lock ring 46 during the running operations. As shown, the THRT 30 includes a radially-outer surface 112 and a radially-inner surface 114. The radially-inner surface 114 is tapered along the axial axis 50 (e.g., an inner diameter increases toward the distal end 110). The radially-inner surface 114 includes one or more grooves 116 (e.g., recesses; circular), and each groove 116 is configured to support one of the one or more sensors 84.

The radially-inner surface 114 of the THRT 30 and the one or more sensors 84 face radially-inwardly toward a radially-outer surface 118 of the extension portion 82 of the lock ring 46, which may also be tapered along the axial axis 50 (e.g., an outer diameter decreases toward a proximal end 120 of the extension portion 82; oppositely tapered as compared to the radially-inner surface 114 of the THRT 30). As the THRT 30 rotates about the tubing hanger 28 and the lock ring 46, the THRT 30 moves axially relative to the tubing hanger 28 and the lock ring 46, as indicated by arrow 122. Thus, the one or more sensors 84 move axially relative to the tubing hanger 28 and the lock ring 46, and the signals generated by the one or more sensors 84 vary as the respective distance between the one or more sensors 84 and the lock ring 46 increases (e.g., vary to reflect or to indicate the respective distance). In some embodiments, the one or more sensors 84 are eddy current sensors that produce an alternating magnetic field, which induces electrical eddy currents in nearby conductive material. The electrical eddy currents oppose the alternating magnetic field, and the signals generated by the eddy current sensors is proportional to an intersection area of alternating magnetic field and the conductive material. Thus, the signals generated by the eddy current sensors enable determination of the distance between the eddy current sensors and the conductive material (in this case, the respective distance between the one or more sensors 84 and the lock ring 46).

FIG. 7 is a perspective cross-sectional view of an embodiment of one of the one or more sensors 84 coupled to the THRT 30 about the lock ring 46, and FIG. 8 is a top view of two sensors 84 coupled to the THRT 30 about the lock ring 46. With reference to FIGS. 7 and 8, the one or more sensors 84 are configured to travel circumferentially across a circumferential gap 130 between opposed ends 132 of the lock ring 46. In particular, as the THRT 30 rotates about the tubing hanger 28 and the lock ring 46, the THRT 30 carries the one or more sensors 84 across the circumferential gap 130 between the opposed ends 132 of the lock ring 46. This enables the one or more sensors 84 to generate the signals that are indicative of the respective distance across the circumferential gap 130, which increases as the lock ring 46 adjusts from the compressed condition to the expanded condition to engage the tubing spool.

FIG. 9 include examples of graphs that represent information derived from the signals generated by the one or more sensors 84 of FIGS. 2-8. With reference to a first graph 140, the one or more sensors generate the signals that reflect changes in inductance as the one or more sensors move axially relative to the lock ring. For example, the signals may indicate a first peak 142 in the inductance as the one or more sensors move circumferentially across one of the opposed ends of the lock ring, a period of low inductance 144 as the one or more sensors move circumferentially across the circumferential gap, and a second peak 146 in the inductance as the one or more sensors move circumferentially across the other one of the opposed ends of the lock ring. Furthermore, the inductance may generally decrease as the one or more sensors move axially relative to the lock ring. It should be appreciated that the peaks 142, 146 may occur as the opposed ends tend to be positioned radially-outwardly relative to other portions of the lock ring.

As discussed herein, in some embodiments, the lock monitoring system may include a gyroscope that is configured to measure an angle of rotation of the THRT and the one or more sensors coupled thereto. Thus, the computing system may process the signals from the one or more sensors, as well as the signals from the gyroscope, to determine the respective distance across the circumferential gap. This may simplify calculations and/or provide more accurate, relevant measurements of the respective distance across the circumferential gap. For example, the computing system may reference a look-up table that correlates the angle of rotation to the respective distance across the circumferential gap (e.g., as indicated in a second graph 148), rather than carrying out more complex calculations and/or measurements that rely upon a rate of rotation of the THRT.

FIGS. 10-13 illustrate an embodiment of the THRT 30 with the one or more sensors 84 and various other components that are used to facilitate the techniques disclosed herein. In particular, as shown in FIG. 10, the THRT 30 includes the one or more sensors 84 near the distal end 110 of the THRT 30. The one or more sensors 84 are communicatively coupled (e.g., via a wired connection(s)) to a first controller 150 of the computing system 100. The THRT 30 may also include the gyroscope 152, a power source 154, one or more communication devices 156, and/or one or more additional sensors.

As noted herein, the gyroscope 152 may generate signals indicative of the angle of rotation of the THRT 30, which may be considered by the computing system 100 to calculate the respective distance across the circumferential gap between the opposed ends of the lock ring 46. The power source 154 may be configured to provide power to the one or more sensors 84, the first controller 150, the gyroscope 152, the one or more communication devices 156, and/or the one or more additional sensors. The one or more additional sensors may collect data indicative of the position of the tubing hanger 28 in the tubing spool 24 and/or data indicative of other conditions in the tubing spool 24. For example, the one or more additional sensors may include one or more pressure and/or temperature sensors 158. As another example, the one or more additional sensors may include one or more displacement sensors 160, such as one or more eddy current sensors, that detect a distance between the THRT 30 and the tubing hanger 28 (e.g., an axial distance across an axial gap 162 between the THRT 30 and the tubing hanger 28). The axial distance across the axial gap 162 may indicate an axial position of the THRT 30 relative to the tubing hanger 28, which in turn may indicate whether the THRT 30 is fully threaded onto the tubing hanger 28 during the running operations and/or whether the THRT 30 is positioned to be out of contact with the lock ring 46 during the locking operations.

In some embodiments, the one or more additional sensors may include one or more acoustic sensors (e.g., piezoelectric, electro-magnetic acoustic transducer(s); having one or more sensor components; one or more transceivers; one or more transmitter/receiver pairs). For example, the one or more acoustic sensors may include a transmitter 166 coupled to the THRT 30 and a receiver 168 coupled to the tubing spool 24 (e.g., along a radially-outer surface of the tubing spool 24). The transmitter 166 may emit acoustic waves (e.g., pulses) that travel through the THRT 30, through the tubing hanger 28, and through the tubing spool 24 to the receiver 168 upon landing the tubing hanger 28 on the spool shoulder 70 of the tubing spool 24 (e.g., a magnitude of the acoustic waves increase upon landing; an increase in the magnitude is a qualitative indication of landing). The receiver 168 may generate signals indicative of a portion of the acoustic waves received at the receiver 168, and the computing system 100 may process the signals to determine that the tubing hanger 28 has landed in the tubing spool 24. For example, the transmitter 166 may emit a train of pulses (e.g., about 5 square wave pulses). Each pulse may have other defined characteristics, such as an amplitude of 25-35 volts (e.g., 30 volts) and/or a period of about 5-10 microseconds (e.g., 7 microseconds; corresponding to a resonant frequency of the transmitter 166). Further, each train of pulses may be sent once every 15-25 milliseconds (e.g., 20 milliseconds), as this allows reverberations from a previous pulse to decrease. In some embodiments, the receiver 168 may generate the signals indicative of the portion of the acoustic waves received at the receiver 168, and the computing system 100 may calculate a root-mean-square (RMS), which may facilitate determining that the tubing hanger 28 has landed in the tubing spool 24 (e.g., the RMS increases upon force increases between the tubing hanger 28 and the tubing spool 24).

In some embodiments, the acoustic waves may travel through the THRT 30, through the tubing hanger 28, and through the tubing spool 24 to the receiver 168 upon contact between one or more seals (e.g., annular seals; o-rings) coupled to the tubing hanger 28 and the tubing spool 24 (e.g., the magnitude of the acoustic waves increases upon contact between the one or more seals and the tubing spool 24, and then further increases upon landing). In this way, the computing system 100 may determine that there is contact between the one or more seals and the tubing spool 24 (e.g., that the tubing hanger 28 is in a near landed position).

In some embodiments, in response to determining that the tubing hanger 28 has landed in the tubing spool 24, the computing system 100 may request the signals generated by the one or more sensors 84 to enable assessment of the locking operations. In particular, the computing system 100 is shown to include the first controller 150 coupled to the THRT 30, as well as a second controller 170. In such cases, the second controller 170 may receive the signals from the receiver 168 and determine that the tubing hanger 28 has contacted the tubing spool 24 (e.g., one or more seals, such as o-ring seals, contacted the tubing spool 24) and/or that the tubing hanger 28 has landed in the tubing spool 24 based on the signals from the receiver 168. Then, the second controller 170 may communicate with the first controller 150 to request that the first controller 150 activate the one or more sensors 84 (and the gyroscope 152) and/or begin transmitting the signals from the one or more sensors 84 (and the gyroscope 152) to the second controller 170. Then, the second controller 170 may process the signals from the one or more sensors 84 (and the signals from the gyroscope 152) as described herein to determine whether the lock ring 46 is in the expanded condition and whether the tubing hanger 28 is in the locked position.

In some embodiments, the computing system 100 may utilize additional acoustic sensors to act as the one or more communication devices 156. For example, the one or more acoustic sensors may transmit pulses as described herein to enable detection of the landing of the tubing hanger 28, and the one or more communication devices 156 may operate at a second frequency (e.g., second range) to enable communication of other signals, requests, and/or information to one or more communication devices 172 of the second controller 170. Further, the one or more communication devices 156 may modulate the acoustic signal to transmit data (e.g., the signals, or information derived from the signals, from the one or more sensors 84) via the acoustic signal. This may provide a quantitative reading of engagement of the lock ring 46. An example of the transmission of the data is represented in FIG. 22. As shown, the one or more communication devices 156 transmit pulses in a pattern (e.g., via modulation) as shown in a graph 171, the pulses are then received at the one or more communication device 172 as shown in graph 173, and the computing device 100 processes the signal (e.g., determines the RMS) to extract digital information (e.g., the RMS value only changes when a pulse is omitted or skipped). However, it should be appreciated that the first controller 150 and the second controller 170 may communicate with one another and/or any other systems via any suitable wired and/or wireless techniques. As shown, the second controller 170 may also be coupled to a power source 174, and the second controller 170 may be configured to communicate with the user device 102. It should be appreciated that the processing steps are merely exemplary and that the processing steps may be distributed between the first controller 150, the second controller 170, the user device 102, or any other suitable processing system or device in any suitable manner. Furthermore, one transmitter (e.g., the transmitter 166 of FIG. 10) and/or one receiver (e.g., the receiver 168) of FIG. 10 may be utilized to detect landing of the tubing hanger 28 within the tubing spool 24, as well as to communicate the data derived from the one or more sensors 84. For example, the one transmitter and the one receiver may operate to detect the landing during a landing process, and then operate to communicate the data during a locking process. Thus, one or more acoustic transmitters and/or one or more acoustic receivers may be utilized to carry out the disclosed techniques. In particular, a strength of a received acoustic signal (e.g., RMS value) is used to detect landing, and then one or more sensors (e.g., the one or more sensors 84) detect an expansion of the lock ring 46 and this measurement is transmitted via modulation of an acoustic signal.

With reference to FIGS. 11-13, the THRT 30 includes the one or more sensors 84, the power source 154, and/or the one or more additional sensors. Certain components shown in FIG. 10, such as hardware components of the first controller 150, the gyroscope 152, the transmitter 166, the one or more communication devices 156, may be arranged in a cavity 180 (e.g., annular cavity; entirely contained in the cavity 180). In some embodiments, certain components may be arranged on and/or positioned about an annular substrate 182 within the cavity 180. When present, the one or more additional sensors may include the one or more pressure and/or temperature sensors 158, the one or more displacement sensors 160, and/or the one or more acoustic sensors with the transmitter 166 and the receiver 168. As shown in FIG. 13, the THRT 30 may include a first ring 184 (e.g., annular) that is sized to circumferentially surround a portion of a body 186 and to mate with the body 186 to form the cavity 180 shown in FIG. 12. The THRT 30 may include a second ring 188 (e.g., annular) that is sized to circumferentially surround the portion of the body 186 and to mate with the first ring 184.

FIG. 14 is an example of a graphical user interface (GUI) 190 that may be presented on a display screen 192, such as the display screen of the user device. The GUI 190 may include an indicator 194, such as a textual and/or color indicator (e.g., the text “LANDED” with a green color indicator), which indicates the position of the tubing hanger. Additionally or alternatively, the GUI 190 may include a schematic diagram of the lock ring 46 and/or the THRT 30. The schematic diagram may be displayed and may change (e.g., in real-time, such as in substantially real-time) during the locking operations (e.g., as the THRT 30 rotates relative to the tubing hanger and the lock ring 46). Thus, the GUI 190 may enable the operator to visualize progress and expansion of the lock ring 46 during the locking operations. Additionally or alternatively, the GUI 190 may include numerical measurements of gap(s), such as one or more indicators 196 of the respective distance between the lock ring 46 and the THRT 30 at one or more locations circumferentially about the lock ring 46 and/or the respective distance across the circumferential gap between the opposed ends of the lock ring 46.

Additionally or alternatively, the GUI 190 may include an indicator 198, such as a textual and/or color indicator (e.g., “LOCKED” with a green color indicator), which indicates the position of the tubing hanger. The indicators 194, 198 may have any of a variety of features that effectively communicate information and/or statuses to the operator, such as “NOT LANDED” with a red color indicator and/or “NOT LOCKED” with a red color indicator. In some embodiments, the indicators 194, 198 may not be visible or may be grayed out until the tubing hanger reaches the landed position (in response, the indicator 194 changes, such as to have the text “LANDED” with the green color indicator) and/or the locked position (e.g., in response, the indicator 198 changes, such as to have the text “LOCKED” with the green color indicator). It should be appreciated that the GUI 190 in FIG. 14 is merely exemplary, and the GUI 190 may present any of a variety of information disclosed herein (e.g., a number of rotations of the THRT 30).

FIG. 15 is a side cross-sectional view of an embodiment of the lock monitoring system 60 that includes one or more sensors 200 coupled to the tubing hanger 28. For example, the one or more sensors 200 may include one or more displacement sensors, such as Hall effect sensors. As shown, a magnet 202 may be coupled to the lock ring 46 (e.g., via fastener(s), adhesive(s), interference fit; embedded within the lock ring 46), and the one or more sensors 200 are configured to detect the magnet 202. Upon detection of the magnet 202 by the sensor 200, the sensor 200 generates a signal that is provided to activate a speaker 204. The signal causes the speaker to emit a sound, which is then detected by a receiver 206 (e.g., microphone) coupled to an outer surface of the tubing spool 24. The receiver 206 may then communicate its receipt of the signal to the computing system (e.g., having the processor(s) and the memory device(s)) to enable the computing system to determine that the tubing hanger 28 is in the locked position. For example, the computing system may determine that the lock ring 46 is fully expanded so that the tubing hanger 28 is in the locked position once the one or more sensors 200 detects the magnet 202. Then, the computing system may provide the output, such as the visible and/or audible alert to the user device.

As shown, the sensor 200 and the speaker 204 are coupled to a power source 208. The sensor 200, the speaker 204, and the power source 208 may be entirely contained in a recess 210 in the tubing hanger 28, and a plate 212 (e.g., annular plate) may be positioned over the recess 210 (e.g., to form part of a radially-outer surface of the tubing hanger 28). One or more seal members 214 (e.g., annular seal members) may be provided to seal the recess 210 to thereby protect the components within the recess 218 (e.g., from fluid contact).

FIG. 16 is a schematic top view of the tubing hanger 28 and the lock ring 46, wherein the lock ring 46 is in the compressed condition. FIG. 17 is a schematic top view of the tubing hanger 28 and the lock ring 46, wherein the lock ring 46 is in the expanded condition. As shown in FIG. 16, the magnet 202 is circumferentially offset from the sensor 200 when the lock ring 46 is in the compressed condition. However, as shown in FIG. 17, the magnet 202 is circumferentially aligned with the sensor 200 when the lock ring 46 is in the expanded condition. Thus, the sensor 200 detects the magnet 202, which initiates the sound from the speaker 204 of FIG. 15. As shown, the magnet 202 may be positioned in an opening 216 (e.g., used to grip/manipulate the lock ring 46 during installation onto the tubing hanger 28) defined proximate to one of the opposed ends of the lock ring 46. However, it should be appreciated that the magnet may be positioned at one of the opposed ends of the lock ring 46 or at any suitable location about the lock ring 46.

FIG. 18 is a schematic top view of an embodiment of the lock ring 46, wherein the lock ring 46 is coupled to a displacement sensor 220. FIG. 19 is a schematic side view of an embodiment of a portion of the lock ring 46 coupled to the displacement sensor 220. The displacement sensor 220 may be configured to measure the respective distance between the opposed ends of the lock ring 46. For example, the displacement sensor 220 may be a draw-wire sensor with a first wire 222 coupled to a first opposed end of the lock ring 46, a second wire 224 coupled to a second opposed end of the lock ring 46, and a potentiometer 226 (e.g., optical encoder with potentiometric output) coupled between the first wire 222 and the second wire 224. The potentiometer 226 generates signals (e.g., data) indicative of the respective distance between the opposed ends of the lock ring 46. Then, a transmitter 228 (e.g., radiofrequency transmitter; acoustic transmitter) that is coupled to the potentiometer 226 transmits the signals to a receiver. It should be appreciated that a power source 230 may be coupled to the potentiometer 226 and the transmitter 228.

FIG. 20 is a side cross-sectional view of an embodiment of the lock monitoring system 60 with the displacement sensor 220 of FIGS. 18 and 19. As shown, the displacement sensor 220 (e.g., via the transmitter 228) may transmit the signals to a receiver 232 (e.g., receiver or transceiver), which may be mounted on the THRT 30 or other suitable location. In some embodiments, the receiver 232 may relay the signals to another receiver 234 mounted outside of the tubing spool 24 and/or remote from the tubing spool 24. The receiver 234 may be coupled to the computing system (e.g., having the processor(s) and the memory device(s)), which may process the signals to determine the respective distance between the opposed ends of the lock ring 46 and to determine whether the tubing hanger 28 is in the locked position. For example, the computing system may determine that the lock ring 46 is fully expanded so that the tubing hanger 28 is in the locked position once the respective distance (or other monitored value) meets or exceeds a threshold. It should be appreciated that the receiver 232 may be omitted (e.g., the transmitter 228 may communicate directly with the receiver 234 coupled to the computing system).

FIG. 21 is a flow diagram of an embodiment of a method 240 of operating the lock monitoring system 60. The following description of the method 240 is described as being performed by a computing system, but it should be noted that any suitable processor-based device or system may be specially programmed to perform any of the methods described herein. Moreover, although the following description of the method 240 is described as including certain steps performed in a particular order, it should be understood that the steps of the method 240 may be performed in any suitable order, that certain steps may be omitted, and/or that certain steps may be added.

In block 242, the method 240 may be begin with receiving one or more signals from one or more sensors that are coupled to a hanger running assembly, which may include a tubing hanger running tool, a tubing hanger, and a lock ring. The one or more sensors may include one or more displacement sensors, such as eddy current sensor(s), Hall effect sensor(s), draw-wire sensor(s), or any other suitable type of displacement sensor(s).

In block 244, the method 240 may include processing the one or more signals to determine a respective distance between the tubing hanger running tool and the lock ring of the tubing hanger. In block 246, the method 240 may include processing the one or more signals to determine a respective distance between the opposed ends of the lock ring. The tubing hanger running tool may contact and compress the lock ring radially-inwardly until the tubing hanger is in the landed position. Then, the tubing hanger running tool may rotate relative to the tubing hanger and the lock ring, which causes the tubing hanger running tool to move axially relative to the tubing hanger and the lock ring. Eventually, the tubing hanger running tool separates from the lock ring, which enables the lock ring to expand to engage the tubing spool. Thus, as the tubing hanger running tool moves away from the lock ring, the respective distances increase.

In block 248, the method 240 may include determining that the lock ring is in the expanded condition based on one or both of the respective distance(s) (or other monitored value(s) that relate to the distance(s)) determined in blocks 244 and 246. For example, the respective distance(s) may be compared to respective thresholds that correspond to the expanded condition of the lock ring. In block 250, the method 240 may include providing an output, such as an indicator that the lock ring is in the expanded condition and/or that the tubing hanger is in the locked position. The output may be a displayed schematic image of the lock ring and/or a displayed indicator (e.g., in a graphical user interface shown on a user device), or any other suitable output. As noted herein, an acoustic signal may be utilized to confirm contact between the tubing hanger (e.g., the one or more seals of the tubing hanger) and the tubing spool and/or to confirm that the tubing hanger has reached the landed position in the tubing spool. In some embodiments, these aspects may be carried out prior to some or all blocks 242-250 of the method 240.

While the lock monitoring system is used to monitor the locking of the tubing hanger in the tubing spool in the illustrated embodiments, it should be appreciated that the lock monitoring system disclosed herein may be used to monitor the locking of other components (e.g., any hanger, such as a casing hanger) within other housings (e.g., any housing, such as the casing spool). Indeed, the lock monitoring system may apply to any structure or system that includes a lock ring that adjusts radially to secure an internal structure (e.g., annular structure; insert) to an external structure (e.g., annular structure; housing). Further, the lock monitoring system may be utilized with other types of lock rings (e.g., other than the lock rings that are externally biased/expands outwardly when the hanger running tool is removed). For example, the lock monitoring system may be utilized with a lock ring that is internally biased/compresses inwardly when the hanger running tool is removed. In such cases, the lock ring may be maintained in an expanded condition by a sleeve (e.g., annular sleeve) and then compress inwardly to a compressed condition upon removal of the sleeve. The lock monitoring system may detect that the lock ring is in the compressed condition, which indicates adequate locking of a corresponding structure (e.g., the hanger within the housing). Thus, it should be appreciated that the lock monitoring system may detect the condition of the lock ring, as well as a change in the condition of the lock ring (e.g., from expanded to compressed; from compressed to expanded; from a first condition to a second condition), to monitor and identify effective locking operations. Additionally, each of the communicative couplings (e.g., the communicative coupling between the sensor(s) and the controller(s), the communicative coupling between the controller(s) and the user device) disclosed above may be established by a wired or wireless connection, as appropriate. The wireless connection may utilize any suitable wireless communication protocol, such as Bluetooth, WiFi, radio frequency identification (RFID), a proprietary protocol, or a combination thereof.

While only certain features have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. It should be appreciated that any features shown and described with reference to FIGS. 1-21 may be combined in any suitable manner.

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 under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

LOCK MONITORING SYSTEM FOR HANGER

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CPC

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