Offshore drilling rig fingerboard latch position indication

A fingerboard latch assembly includes a latch configured for operational engagement with a fingerboard for lockingly retaining at least one tubular to the fingerboard. The latch is movable within a range of motion extending from at least a locked position to an unlocked position. A positioner operatively engaged with the latch is communicably couplable to a process control network (PCN), and is sized and shaped for receipt within a latch channel of the fingerboard. The positioner is configured to move the latch within the range of motion in response to signals received from the PCN, to capture position data for the latch, including the position of the latch at a plurality of points within the range of motion, and to communicate the captured position data to the PCN.

BACKGROUND

1. Technical Field

This invention relates to drilling rig fingerboards, and more particularly to a fingerboard latch assembly for providing real time latch position feedback via a process control network.

2. Background Information

Oil and gas well drilling systems include numerous types of piping, referred to generally as “tubulars”. Tubulars include drill pipes, casings, and other threadably connectable oil and gas well structures. Long “strings” of joined tubulars, or drill strings, are typically used to drill a wellbore and to prevent collapse of the wellbore after drilling. The drill strings are typically stored in a structure commonly referred to as a fingerboard. Fingerboards typically include an elongated support structure(s) or “fingerboard row(s)” each capable of receiving a plurality of drill strings. Each drill string is typically individually secured to one of the finger rows by a corresponding latch, which is movable between a locked and an unlocked position. On offshore drilling rigs, these tubulars are typically stacked upright in the fingerboards, while the latches hold the tubular in place until needed.

In some fingerboards, the latches are manually moved between the locked and unlocked positions by an oil or gas well worker who walks across the fingerboards to manually move the latches to the desired locked or unlocked position. Due to the extreme height of the fingerboards, (in some instances 90 feet tall or more) the manual operation of the latches by the worker is undesirably dangerous. This practice may be particularly dangerous when the worker moves the latches between the locked and unlocked position by kicking the latches into or out of the locked position as the worker walks across the fingerboards, which is not an uncommon practice.

In an effort to make fingerboards less dangerous some manufacturers include automated latches that are pneumatically actuated. Although these latches may decrease the danger to the worker relative to the aforementioned manual approaches, they are not without drawbacks. For example, when the drilling rig operator needs to collect and use one tubular he will press a button on a control panel that will raise its latch to its unlocked position to release the tubular. However, conventional pneumatic latch controls typically do not provide feedback to the operator of the actual latch position. In some cases the latch will not raise fully and at its height on the derrick, it is generally difficult to confirm the actual position of the latch. In such a situation, a worker generally needs to climb up the derrick and walk out onto the fingerboard to determine the position of the latch. As mentioned above, the height of the fingerboard tends to make this a dangerous procedure. Moreover, in some cases the drilling rig operator will press the button again, without first determining the latch position, sending another signal in an effort to open it. This may cause the second latch behind the first to open, releasing its pipe string which may then collide with the unreleased drill pipe. This collision may damage the fingerboard making it inoperable. Since oil rigs are generally 8-10 miles off shore, service/repair of the fingerboard may be difficult and/or time consuming. Also, as a result of the collision, the pipes may be released to crash onto the rig platform below possibly harming people and causing damage.

It is also noted that by virtue of their function, any equipment used in connection with the fingerboards is prone to damage due to the relatively harsh conditions associated with the mud and salt water, such as may be carried by the tubulars as they are withdrawn from a well and placed back into the fingerboards for storage and re-use.

Thus, a need exists for a fingerboard latch actuation system that addresses drawbacks associated with the prior art.

SUMMARY

In one aspect of the present invention, a fingerboard latch assembly includes a latch configured for operational engagement with a fingerboard for lockingly retaining at least one tubular to the fingerboard. The latch is movable within a range of motion extending from a locked position to an unlocked position. A positioner operatively engaged with the latch is communicably couplable to a process control network (PCN). The positioner is configured to move the latch within the range of motion in response to signals received from the PCN, and to capture position data for the latch substantially in real time. The position data includes the position of the latch at substantially any point within the range of motion. The positioner is also configured to transmit the captured position data to the PCN, substantially in real time.

In another aspect of the invention, a fingerboard latch assembly includes a latch configured for operational engagement with a fingerboard for lockingly retaining at least one tubular to the fingerboard. The latch is movable within a range of motion extending from at least a locked position to an unlocked position. A positioner operatively engaged with the latch is communicably couplable to a process control network (PCN), and is sized and shaped for receipt within a latch channel of the fingerboard. The positioner is configured to move the latch within the range of motion in response to signals received from the PCN, and to capture position data for the latch, including the position of the latch at a plurality of points within the range of motion. The positioner is also configured to communicate the captured position data to the PCN.

In yet another aspect of the invention, a method of operating a fingerboard includes placing at least a portion of the fingerboard latch assembly of the preceding aspect of the invention within a latch channel of the fingerboard. This method further includes receiving a signal via a process control network (PCN), at the fingerboard latch assembly, and moving the latch in response to the signal, within its range of motion. The latch assembly captures position data for the latch at a plurality of points within the range of motion, and transmits the captured position data via the PCN.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural and system changes may be made without departing from the spirit and scope of the present invention. In addition, well-known structures, circuits and techniques have not been shown in detail in order not to obscure the understanding of this description. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

General Overview

Embodiments of the present invention control and transmit the position of automated latches on fingerboards. This is accomplished by the use of positioners mounted to latches on the fingerboard assemblies. These positioners control movement and provide feedback of a pneumatic control valve, pneumatic cylinder, and/or pneumatic piston. Operators may provide a signal/communication through a control or host system to the positioner to open and/or close the latch. In response to this control signal, the positioner will open and/or close the latch while also providing a feedback signal (e.g., electrical, pneumatic, fieldbus, resistance and/or wireless, etc.) back to the control or host system indicating the specific position of the latch, e.g., open, closed, or positions therebetween.

Terminology

As used herein, the terms “fieldbus” and/or “process control network” refer to a digital, two-way, multi-drop communication link among intelligent measurement and control devices, and serves as a local area network (LAN) for advanced process control, remote input/output and high speed factory automation applications. The term ‘real time’ refers to sensing and responding to external events nearly simultaneously (e.g., within milliseconds or microseconds) with their occurrence, or sufficiently fast to enable the device to keep up with an external process (for example, sufficiently fast as to avoid losing data generated by the FDs).

Referring now to the Figures, embodiments of the present invention will be more thoroughly described. These embodiments are directed to fingerboards10(FIG. 1A) for storing a plurality of threaded tubulars14(FIG. 1B). Each fingerboard10has a plurality of latches18for securing the threaded tubulars to the fingerboard. Each latch may include a pneumatic cylinder22(FIG. 3) that is pneumatically actuatable to move a latch finger between a locked (closed) position and an unlocked (open) position. In the closed position, the latch secures a corresponding threaded tubular to the fingerboard. When the latch is moved to its open position, a corresponding threaded tubular may be removed from the fingerboard.

As best shown inFIGS. 1A,1B, and2, fingerboards10according to one embodiment of the present invention, include a plurality of elongated support structures12(hereinafter fingerboard rows12) each capable of receiving a plurality of threaded tubulars14. Each fingerboard row12includes adjacent structures (fingers)16, laterally spaced apart to receive the plurality of threaded tubulars14therein. In the depicted embodiment, each fingerboard row12receives fourteen threaded tubulars14. However, in other embodiments each fingerboard row12may receive any appropriate number of threaded tubulars14. Note that the numbers one through fourteen on the threaded tubulars shown in the leftmost fingerboard row12ofFIG. 1Band the numbers one through twelve on the uppermost threaded tubular in each fingerboard row12are merely shown for reference purposes.

As mentioned above, each fingerboard row12includes a plurality of corresponding latches18. Latches18may be substantially any fingerboard latch known to those skilled in the art, as may be modified in accordance with the teachings of the present invention. In the depicted embodiment, each latch18secures a corresponding threaded tubular14within its corresponding fingerboard row12. However, in other embodiments each latch18may be used to secure more than one threaded tubular14to the fingerboard row12.

Turning now toFIG. 3, each latch18includes an arm20, which is pivotably mounted to a yoke23, for movement between its locked/closed position as shown (as also shown inFIGS. 1B and 2) and its unlocked/open position as shown in phantom at20′. In the locked position, the latch18engages its corresponding threaded tubular14(FIG. 2) to secure the threaded tubular14within a fingerboard row12. In the unlocked position, the latch18disengages its corresponding threaded tubular14to allow the threaded tubular14to be removed from its fingerboard row12. In the unlocked position, the latch18also allows for the insertion of the threaded tubular14into its corresponding fingerboard row12, where it may then be secured by moving the latch18from the unlocked position to the locked position.

As shown, latch18may be moved between the locked and unlocked positions by a pneumatic cylinder22configured to mechanically actuate (pivot) the latch arm20between the locked and unlocked positions. For example, as best shown inFIG. 4, in the particular embodiments shown and described herein, a piston24of cylinder22is extended when in the unlocked position, and retracted when in the locked position as shown at24′. The end of piston24may thus be pivotably coupled to the arm20in any convenient manner, such as with a mechanical linkage25as shown in FIGS.3and6A-6D, to effect the described locking and unlocking.

Each latch18may be mounted to its corresponding fingerboard row12using substantially any desired mechanical fastening means, such as riveting, threaded fasteners (as shown), welding, press fit, or any combination thereof. In the depicted embodiment, each latch18may be secured to its corresponding fingerboard row12by inserting a portion thereof into an opening (latch channel)40(FIG. 5) in the fingerboard row12. In the embodiment shown, yoke23is sized and shaped for receipt within the similarly sized and shaped latch channel40, e.g., up to flange portion29thereof. Each latch18may thus be inserted into latch channel40until the flange29engages an upper surface of the fingerboard12. Once this full insertion is reached, each latch18may be secured to the fingerboard row12by one or more of the aforementioned mechanical fastening means, such as threaded fasteners27passing through flange29as shown.

It should be recognized that the latches of substantially any configuration may be used in various embodiments of the present invention. Non-limiting examples of various latches that may be modified as taught herein for use in embodiments of the present invention are shown at118,218,318and418inFIGS. 6A-6D. These latches may all include pneumatic cylinders as shown and described hereinabove, though substantially any other actuation devices known to those skilled in the art, including electrically and/or hydraulically operated devices, may be used without departing from the scope of the present invention. As shown, the latches ofFIGS. 6A-6Dare substantially similar to one another but for the use of latch arms120,220,320, and420, of various sizes and shapes as may be desired for various applications.

Turning now toFIG. 7, an embodiment of the present invention includes a latch assembly26having a latch18, as discussed hereinabove, which is equipped with a positioner30, such as the SRD991 pneumatic positioner available from Invensys Systems, Inc. (Foxboro, Mass.). As shown, the positioner30is fastened, via an L-bracket32, onto the latch18, e.g., with a clamp34extending circumferentially about the pneumatic cylinder22. As also shown, the piston24at one end of cylinder22is pivotably coupled to mechanical linkage25, while the other end31of the cylinder is secured to ground33.

Turning now toFIGS. 8-9B, an alternate embodiment of the present invention, shown as latch assembly26′, includes a modified positioner30′. A plurality of assemblies26′ are shown linked to one another in series, e.g., as in a typical installation within a fingerboard10(FIGS. 1A-2). The pivot arms20(FIG. 3) have been omitted from these figures for clarity. In this embodiment, positioner30′ may include the aforementioned SRD991, as modified to fit into a box at the (e.g., bottom) end31of the cylinder latch opposite the yoke23, to provide a relatively compact assembly sized and shaped to fit within the latch channel40(FIG. 5) of a conventional fingerboard10, as discussed hereinabove. This mounting configuration effectively houses the positioner30′ within the fingerboard10to help protect the positioner30′ from the relatively harsh environmental conditions associated with oil rig operation, as mentioned hereinabove. Positioner30′ is substantially similar to positioner30shown and described hereinabove, though it may be modified to exclude the onboard display/user interface common to commercial versions of the SRD991. Instead, one or more ports (not shown) may be provided to enable users to plug a portable display/user interface into the assembly26′, e.g., for initial setup and/or diagnostics. Alternatively, setup and diagnostics may be accomplished remotely, e.g., via a process control network (PCN) connection42as discussed below.

As also shown, PCN and pneumatic supply lines42and44, which in particular embodiments are routed within the fingerboards10, are connected to the positioners30′. A pneumatic line46pneumatically connects each positioner30′ to its respective cylinder22. Thus, in the embodiment shown, lines42,44and46are all configured for being disposed within the fingerboards10, to help protect them from the harsh environmental conditions.

In the various embodiments shown and described herein, the positioner30,30′ is configured to provide feedback to the user to indicate not only when each latch18,118, etc., is disposed in its locked and unlocked positions, but to also indicate the position of the latch at a plurality of points within its range of motion between the locked and unlocked positions. This feedback may be provided using one or more position sensors50(FIG. 4). In particular embodiments, sensor(s)50may include one or more limit switches used to confirm particular discrete positions of the latch, e.g., at either end (locked and unlocked positions) and/or midrange positions within its range of motion. Sensor(s)50may also include one or more potentiometers, such as may be disposed internally to the cylinder22, to provide a signal corresponding to substantially any position with the range of motion of the latch. In particular embodiments, the potentiometer(s) may be a conventional resistive (analog) device, configured to generate a signal which may be converted by the positioner into a digital signal suitable for transmission via the PCN line42. Moreover, a combination of potentiometer and limit switches may be used, e.g., with the limit switch(es) used to calibrate the potentiometer(s). It should be recognized that substantially any type of sensor(s) known to those skilled in the art may be used in these embodiments, without departing from the scope of the present invention. However, particular embodiments use sensors configured to directly engage moveable portions of the latch. Such direct engagement may be effected in either a contact or non-contact manner, e.g., using conventional limit switches, and/or using non-contact devices such as conventional inductive, capacitive, magnetic, and photoelectric sensors, and the like. Moreover, in particular embodiments, the sensor(s)50is disposed for being housed within the latch channel along with the positioner30′ and a portion of the latch18,118, etc., such as by placing sensor50internally to the cylinder22as described hereinabove.

It should be noted that the positioners30,30′ may be configured to communicate via network connection42using substantially any communication protocol known to those skilled in the art of industrial automation. Examples of protocols that may be used include Profibus, ModBus, FOUNDATION fieldbus, HART, Ethernet, and conventional 4-20 ma analog signal, etc., and combinations thereof. Moreover, both wired and wireless protocols may be used, as well as non-electrical (e.g., pneumatic) signaling approaches. In this regard, although network connection42is shown as a hard-wired electrical connection, substantially any type of connection known to those skilled in the art, including wireless or non-electrical (e.g., pneumatic) connections may be used without departing from the scope of the present invention. In particular embodiments, the positioners30,30′ may be configured to transmit latch position data via PCN42substantially in real time, e.g., to provide substantially real time position information to the PCN operator. The positioners30,30′ may push this information to the network42, and/or may provide this real time information in response to requests sent via the PCN.

Having described exemplary embodiments of latch assemblies of the present invention, an exemplary method in accordance with the present invention will be described with reference to the following Table I. As shown therein, at70, at least a portion of a fingerboard latch assembly26,26′, etc., is received within a latch channel of a fingerboard. At72, the fingerboard latch assembly receives a signal via the PCN. At74, the latch is moved in response to the signal, and position data for the latch is captured76at a plurality of points within its range of motion. At78, the latch assembly transmits the captured data via the PCN.

Optional aspects of this method are shown at80-86of Table II, and include80capturing position data at substantially any point within the range of motion;82capturing position data using a potentiometer;84disposing the positioner within the latch channel; and86, effecting the capturing76and transmitting78substantially in real time.

TABLE I70Fingerboard latch assembly disposed within a latch channel;72Signal received at fingerboard latch assembly;74Latch moved in response to signal, within range of motion;76Latch position data captured at a plurality of points withinthe range of motion;78Position data transmitted via PCN.

TABLE II80capture position data at substantially any point within therange of motion82capture position data using a potentiometer84dispose the positioner within latch channel86capturing 76 and transmitting 78 substantially in real time

In the preceding specification, the invention has been described with reference to specific exemplary embodiments for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.

It should be further understood that any of the features described with respect to one of the embodiments described herein may be similarly applied to any of the other embodiments described herein without departing from the scope of the present invention.