Patent Application
20250043639
The present invention generally involves an interlock for a drill rig and a method for operating the drill rig. Particular embodiments of the present invention may be incorporated into land-based or offshore drill rigs used for oil/gas production and/or well service operation to reduce or prevent personnel injury or equipment damage.
Drill rigs are commonly used in oil and gas production and well service operations to bore substantial distances below the earth's surface. A drill rig generally includes a drawworks for raising and lowering a drill string in a borehole. The drill string refers to segments of pipe serially connected to extend into the borehole. The drawworks generally includes a drive system releasably engaged to a large drum or spool to retract or release a cable connected to the drill string. The cable extends from the drum to a derrick that supports a block and tackle arrangement holding a traveling block that provides a mechanical advantage for raising and lowering the drill string. A clutch releasably connects the drive system to the drum to rotate the drum to reel in the cable and raise the drill string. To lower the drill string, the clutch may disengage the drive system from the drum, and a brake connected to the drum may be released to allow the weight of the drill string to rotate the drum to release the cable from the drum.
Raising and lowering the drill string typically involves coordinated efforts between multiple operators on the drill rig to add/remove segments from the drill string, adjust the weight of the travelling block, and operate the drawworks. The noise associated with the operations, the weight of the equipment and machinery, and various other personnel and environmental factors create an inherently dangerous operating environment. For example, operating the drive system at too low of a speed or too high of a gear for the combined weight of the travelling block and drill string may cause the drive system to stall. Unless the operators respond quickly to apply the brake, the weight of the drill string and traveling block will rotate the drum to release the cable, resulting in uncontrolled movement of the drill string and travelling block, seriously damaging the equipment and personnel, interrupting operations, requiring expensive repairs and training, and leading to lost revenue. Therefore, the need exists for an improved drill rig and method for operating the drill rig that incorporates one or more interlocks to arrest the uncontrolled release of the cable in the event that the drive system stalls or otherwise ceases to operate to enhance safe and reliable operation of the drill rig.
Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
One embodiment of the present invention is an interlock for a drive system of a drawworks that includes a means for sensing an operating condition of the drive system. An interlock signal is generated by the means for sensing the operating condition of the drive system, and the interlock signal is reflective of the operating condition of the drive system. A lock operably connected to the drawworks receives the interlock signal and disables operation of the drawworks if the interlock signal meets a predetermined criterion that indicates that the drive system is not operating.
An alternate embodiment of the present invention is an interlock for a drill rig that includes a drawworks having a drum operably connected to a drive system and a brake. A cable extends from said drum of the drawworks to a block and tackle arrangement holding a traveling block, and operation of the drawworks causes the drum to release or retract the cable. The interlock further includes a means for sensing an operating condition of the drive system. An interlock signal is generated by the means for sensing the operating condition of the drive system, and the interlock signal is reflective of the operating condition of the drive system. A lock operably connected to the drawworks receives the interlock signal and disables operation of the drawworks if the interlock signal meets a predetermined criterion that indicates that the drive system is not operating.
In yet another embodiment of the present invention, a method for operating a drill rig includes operating a drive system in a drawworks to raise and lower a drill string. The method further includes sensing an operating condition of the drive system, generating an interlock signal that reflects the operating condition of the drive system, and disabling the drawworks if the interlock signal meets a predetermined criterion that indicates that the drive system is not operating.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used in the claims, the definite article “said” identifies required elements that define the scope of embodiments of the claimed invention, whereas the definite article “the” merely identifies environmental elements that provide context for embodiments of the claimed invention that are not intended to be a limitation of the claim.
Embodiments of the present invention include a drill rig and method for operating the drill rig that incorporate one or more interlocks to enhance safe and reliable operation of the drill rig. Referring now to the drawings,
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The predetermined criterion may be selected to indicate that the drive system 30 is stalled, inoperable, or not operating. For example, the predetermined criterion may be a minimum speed or RPM for the drive system 30, and if the interlock signal 60 generated by the speed sensor 46 falls below this predetermined criterion, the lock 62 disables operation of the drawworks 12. Alternately, the predetermined criterion may be a combination of a minimum speed or RPM for each gear, and if the interlock signal 60 generated by the speed sensor 46 and gear sensor 48 indicates that the speed of the drive system 30 is too low for a particular gear, the lock 62 disables operation of the drawworks 12. Alternately or in addition, the predetermined criterion may be a low oil pressure, low fuel flow, engine trouble condition, high transmission temperature, or high oil temperature, and if the interlock signal 60 generated by the respective oil pressure 50, fuel flow 52, engine trouble 54, transmission temperature 56, or oil temperature 58 sensors exceed the predetermined condition, the lock 62 disables operation of the drawworks 12.
As shown in
At block 74, the method generates the interlock signal 60 that reflects the operating condition of the drive system 30. At block 76, the method selectively transmits the interlock signal 60 to the lock 62 to enable an operator to effectively override the interlock 40 by either preventing the interlock signal 60 from reaching the lock 62 or transmitting the interlock signal 60 to the lock 62 to disable the drawworks 12. At block 78, the method compares the interlock signal 60 to the predetermined criteria and disables the drawworks 12 if the interlock signal 60 meets the predetermined criterion which indicates that the drive system 30 is not operating. As shown at block 80, the method may disable the drawworks 12 by actuating the brake 32, releasing the clutch 28, and/or otherwise disabling the drive system 30. The interlock 40 and method for operating the drill rig 10 thus provide enhanced safety and protection for both equipment and personnel by preventing inadvertent operation of the drawworks 12 when the operating condition of the drive system 30 indicates that the drive system 30 is stalled, inoperative, or not operating.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
