Patent Application
20140116687
1. Field of the Disclosure
The present disclosure generally relates to a method for makeup evaluation visualization to automatically detect acceptable or unacceptable connections during tubular makeup.
2. Description of the Related Art
In wellbore construction and completion operations, a wellbore is formed to access hydrocarbon-bearing formations (e.g., crude oil and/or natural gas) by the use of drilling. Drilling is accomplished by utilizing a drill bit that is mounted on the end of a drill string. To drill within the wellbore to a predetermined depth, the drill string is often rotated by a top drive or rotary table on a surface platform or rig, or by a downhole motor mounted towards the lower end of the drill string. After drilling to a predetermined depth, the drill string and drill bit are removed and a string of casing is lowered into the wellbore. An annulus is thus formed between the casing string and the formation. The casing string is temporarily hung from the surface of the well. A cementing operation is then conducted in order to fill the annulus with cement. The casing string is cemented into the wellbore by circulating cement into the annulus defined between the outer wall of the casing and the borehole. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.
A drilling rig is constructed on the earth's surface or floated on water to facilitate the insertion and removal of tubular strings (e.g., drill pipe, casing, sucker rod, riser, or production tubing) into a wellbore. The drilling rig includes a platform and power tools, such as an elevator and slips, to engage, assemble, and lower the tubulars into the wellbore. The elevator is suspended above the platform by a draw works that can raise or lower the elevator in relation to the floor of the rig. The slips are mounted in the platform floor. The elevator and slips are each capable of engaging and releasing a tubular and are designed to work in tandem. Generally, the slips hold a tubular or tubular string that extends into the wellbore from the platform. The elevator engages a tubular joint and aligns it over the tubular string being held by the slips. One or more power drives, e.g. a power tong and a spinner, are then used to thread the joint and the string together. Once the tubulars are joined, the slips disengage the tubular string and the elevator lowers the tubular string through the slips until the elevator and slips are at a predetermined distance from each other. The slips then reengage the tubular string and the elevator disengages the string and repeats the process. This sequence applies to assembling tubulars for the purpose of drilling, deploying casing, or deploying other components into the wellbore. The sequence is reversed to disassemble the tubular string.
The present disclosure generally relates to a method for makeup evaluation visualization to automatically detect acceptable or unacceptable connections during tubular makeup. In one embodiment, a method of connecting a first threaded tubular to a second threaded tubular includes: engaging threads of the tubulars; and rotating the first tubular relative to the second tubular, thereby making up the threaded connection. The method further includes, during makeup of the threaded connection: measuring torque applied to the connection; measuring turns of the first tubular; and detecting a shoulder position. The method further includes: displaying the measured torque and turns; overlaying a reference curve onto the display; evaluating the threaded connection by comparing the measured torque and turns to the reference curve; and graphically displaying the evaluation.
In another embodiment, a tubular makeup system includes: a power drive operable rotate a first threaded tubular relative to a second threaded tubular; a torque cell; a turns counter; and a programmable logic controller (PLC) operably connected to the power drive and in communication with the torque cell and turns counter. The PLC is configured to control an operation including: engaging threads of the tubulars; and rotating the first tubular relative to the second tubular, thereby making up the threaded connection. The operation further includes, during makeup of the threaded connection: measuring torque applied to the connection; measuring turns of the first tubular; and detecting a shoulder position. The operation further includes: displaying the measured torque and turns; overlaying a reference curve onto the display; evaluating the threaded connection by comparing the measured torque and turns to the reference curve; and graphically displaying the evaluation.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
During makeup, the box 10 is engaged with the pin 8 and then screwed onto the pin by relative rotation therewith. During continued rotation, the annular sealing areas 16, 18 contact one another, as shown in
During continued rotation, the annular sealing areas 16, 18 contact one another causing a slight change (specifically, an increase) in the torque rate, as illustrated by point 54. Thus, point 54 corresponds to the seal position shown in
The power tong 102 may include a power tong housing provided with a through aperture that corresponds to the guide columns 110, and an undivided drive ring connected via a bearing ring (not shown). The bearing ring may have a toothed ring (not shown) in mesh with cogwheels (not shown) on one or more hydraulic motors (not shown), such as two. One of the motors may be a spinner motor (high speed, low torque) and the other motor may be one or more torque motors (high torque, low speed). The toothed ring may be coupled to the drive ring by screw-bolt-joints (not shown). The hydraulic motors may be arranged to rotate the drive ring about the drilling centre 108. The two hydraulic motors may be disposed on diametrically opposite sides of the drive ring. A cover may be provided to cover the power tong housing.
In the drive ring and co-rotating with this may be two crescent-shaped groups 140g (only one shown) of clamps. Each group 140g of clamps may be provided with one or more, such as three, clamps distributed around the drilling center 108. Each clamp may include a cylinder block provided with one or more, such as three, cylinder bores arranged in a vertical row. In each cylinder bore may be a corresponding longitudinally displaceable piston that seals against the cylinder bore by a piston gasket. A rear gasket may prevent pressurized fluid from flowing out between the piston and the cylinder bore at the rear end of the piston.
The pistons may be fastened to the housing of the group 140g of clamps by respective screw-bolt-joints. On the part of the cylinder block facing the drilling center 108 there may be provided a gripper. The gripper may be connected to the cylinder block by fastening, such as with dovetail grooves or screw-bolt-joints (not shown). Surrounding the drive ring there may be provided a swivel ring that seals by swivel gaskets, the swivel ring may be stationary relative to the power tong housing. The swivel ring may have a first passage that communicates with the plus side of the pistons via a first fluid connection, a second passage that communicates with the minus side of the pistons via a second fluid connection, and a further passage. The cylinder and the piston may thereby be double acting. The swivel ring, swivel gaskets and drive ring may together form a swivel coupling.
The backup tong 104 may also include the clamp groups. The back-up tong 104 may further include a back-up tong housing with guides 176 that correspond with the guide columns 110, and a retainer ring for two groups of clamps. At the guides 176 there may be cogwheels that mesh with respective pitch racks of the guide columns 110. Separate hydraulic motors may drive the cogwheels via gears. A pair of hydraulic cylinders may be arranged to adjust the vertical distance between the power tong 102 and the back-up tong 104.
In operation, when the tubular joint 2 is to be added to tubular string 20 (already including tubular joint 4), the assembly 100 may be displaced vertically along the guide columns 110 by the hydraulic motors, the gears, the cogwheels and the pitch racks until the back-up tong 104 corresponds with the pin 8 of the tubular string 20. The box 10 of the coupling 6 may have been made up to the pin 8 of the joint 2 offsite (aka bucking operation) before the tubulars 2, 4 are transported to the rig. Alternatively the coupling 6 may be bucked on the joint 4 instead of the joint 2. Alternatively, the coupling 6 may be welded to one of the tubulars 2, 4 instead of being bucked on.
The vertical distance between the back-up tong 104 and the power tong 102 may be adjusted so as to make the grippers correspond with the coupling 6. The clamps may be moved up to the coupling 6 by pressurized fluid flowing to the first passage in the swivel ring and on through the first fluid connection to the plus side of the pistons. The excess fluid on the minus side of the pistons may flow via the second fluid connection and the second passage back to a hydraulic power unit (not shown).
The grippers may then grip their respective pin or box while the hydraulic motors rotate the drive ring and the groups 140g of clamps about the drilling center 108, while at the same time constant pressure may be applied through the swivel ring to the plus side of the pistons. The power tong 102 may be displaced down towards the back-up tong 104 while the screwing takes place. After the desired torque has been achieved, the rotation of the drive ring may be stopped. The clamps may be retracted from the tubular string 20 by pressurized fluid being delivered to the minus side of the pistons via the swivel ring. The assembly 100 may be released from the tubular string 20 and moved to its lower position.
When a joint 2 is to be removed from the tubular string 20, the operation is performed in a similar manner to that described above. When tools or other objects of a larger outer diameter than the tubular string 20 are to be displaced through the assembly 100, the grippers may easily be removed from their respective clamps, or alternatively the groups 140g of clamps can be lifted out of the drive ring.
Alternatively, other types of tong assemblies may be used instead of the tong assembly 100.
A programmable logic controller (PLC) 216 of the control system 206 may monitor the turns count signals 210 and torque signals 214 from the respective sensors 208, 212 and compare the measured values of these signals with predetermined values 223-230. The predetermined values 223-230 may be input by an technician for a particular connection. The predetermined values 223-230 may be input to the PLC 216 via an input device 218, such as a keypad.
Illustrative predetermined values 223-230 which may be input, by an technician or otherwise, include minimum and maximum delta gradient values 223, a shoulder threshold gradient 224, a dump torque value 226, minimum and maximum delta turns values 228, minimum and maximum torque values 230, and reference curve data 231. The minimum and maximum torque values 230 may include a set for the shoulder position and a set for the final position. The torque values 230 may be derived theoretically, such as by finite element analysis, or empirically, such as by laboratory testing and/or analysis of historical data for a particular connection. The dump torque value 226 may simply be an average of the final minimum and maximum torque values 230. During makeup of the connection 1, various output may be observed by an technician on output device, such as a video monitor, which may be one of a plurality of output devices 220. A technician may observe the various predefined values which have been input for a particular connection. Further, the technician may observe graphical information such as the torque rate curve 50 and the torque rate differential curve 50a. The plurality of output devices 220 may also include a printer such as a strip chart recorder or a digital printer, or a plotter, such as an x-y plotter, to provide a hard copy output. The plurality of output devices 220 may further include an alarm, such as a horn or other audio equipment, to alert the technician of significant events occurring during makeup, such as the shoulder position, termination, and/or a violation of a criterion.
Upon the occurrence of a predefined event(s), the PLC 216 may output a dump signal 222 to the TRU 204 to automatically shut down or reduce the torque exerted by the tong assembly 100. For example, dump signal 222 may be issued in response to the measured torque value reaching the dump torque 226 and/or a bad connection.
The comparison of measured turn count values and torque values with respect to predetermined values is performed by one or more functional units of the PLC 216. The functional units may generally be implemented as hardware, software or a combination thereof. The functional units may include one or more of a torque-turns plotter algorithm 232, a process monitor 234, a torque gradient calculator 236, a smoothing algorithm 238, a sampler 240, a database 242 of reference curves, a connection evaluator 252, and a target detector 254. The process monitor 234 may include one or more of a thread engagement detection algorithm 244, a seal detection algorithm 246, a shoulder detection algorithm 248, and a graphical evaluator algorithm 250. Alternatively, the functional units may be performed by a single unit. As such, the functional units may be considered logical representations, rather than well-defined and individually distinguishable components of software or hardware.
In operation, one of the threaded members (e.g., tubular 2 and coupling 6) is rotated by the power tong 102 while the other tubular 4 is held by the backup tong 104. The applied torque and rotation are measured at regular intervals throughout the makeup. The frequency with which torque and rotation are measured may be specified by the sampler 240. The sampler 240 may be configurable, so that an technician may input a desired sampling frequency. The torque and rotation values may be stored as a paired set in a buffer area of memory. Further, the rate of change of torque with respect to rotation (hereinafter “torque gradient”) may be calculated for each paired set of measurements by the torque gradient calculator 236. The smoothing algorithm 238 may operate to smooth the torque-turns curve 50 and/or torque gradient curve 50a (e.g., by way of a running average). These values (torque, rotation, and torque gradient) may then be plotted by the plotter 232 for display on the output device 220.
The values (torque, rotation, and torque gradient) may then be compared by the connection evaluator 252, either continuously or at selected events, with predetermined values, such as the values 223-230. Based on the comparison of the measured and/or calculated values with the predefined values 223-230, the process monitor 234 may determine the occurrence of various events and the connection evaluator 252 may determine whether to continue rotation or abort the makeup. The thread engagement detection algorithm 244 may monitor for thread engagement of the pin 8 and box 10. Upon detection of thread engagement a first marker is stored. The marker may be quantified, for example, by time, rotation, torque, the torque gradient, or a combination of any such quantifications. During continued rotation, the seal detection algorithm 246 monitors for the seal condition. This may be accomplished by comparing the calculated torque gradient with a predetermined threshold seal condition value. A second marker indicating the seal condition may be stored if/when the seal condition is detected. At this point, the torque value at the seal condition may be evaluated by the connection evaluator 252.
For example, a determination may be made as to whether the turns value and/or torque value are within specified limits. The specified limits may be predetermined, or based off of a value measured during makeup. If the connection evaluator 252 determines a bad connection, rotation may be terminated. Otherwise, rotation continues and the shoulder detection algorithm 248 monitors for the shoulder position. This may be accomplished by comparing the calculated torque gradient with the shoulder threshold gradient 224. When the shoulder position is detected, a third marker indicating the shoulder position is stored. The connection evaluator 252 may then determine whether the torque value at the shoulder position is acceptable by comparing to the respective input torque values 230.
Upon continuing rotation, the target detector 254 compares the measured torque to the dump torque value 226. Once the dump torque value 226 is reached, rotation may be terminated by sending the dump signal 222. Alternatively, the dump signal 222 may be issued slightly before the dump torque 226 is reached to account for system inertia. Once the connection is complete, the connection evaluator 252 may calculate a delta turns value based on the difference between the final turns value and the turns value at the shoulder condition. The connection evaluator 252 may compare the delta turns value with the input delta turns values 228. Similarly, the connection evaluator may compare the final torque value to the respective input torque values 230. The connection evaluator 252 may calculate a delta torque value based on the difference between the final torque value and the torque value at the shoulder condition. The connection evaluator 252 may calculate a delta gradient value using delta torque and delta turns values and compare it with the respective input values 223. If either criteria is not met, then the connection evaluator 252 may indicate a bad connection.
Alternatively, a delta turns value may be entered instead of the dump torque 226. The target detector 254 may then calculate a target turns value using the shoulder turns and the delta turns value (target turns equals shoulder turns plus delta turns).
Alternatively, the reference curves may be constructed by averaging data of the previously assembled good connections to create an average reference curve (not shown). The average reference curve may then be overlayed onto the torque-turns plot or the first and second reference curves may be constructed using a standard deviation of the average curve. Alternatively, the reference curves may be theoretically constructed and may or may not be empirically calibrated.
The graphical evaluator 250 may also partition the torque-turns plot into one or more regions using the database 242 and respective input values 228, 230, such as a reference region, delta turns region, shoulder torque region, and a final torque region. During makeup and/or after termination of the connection, the graphical evaluator 250 may compare the torque-turns curve and determine if the curve is within the reference region. If the torque-turns curve is within the reference region, the graphical evaluator 250 may fill the region with a favorable color, such as green (depicted with cross hatching). If the torque-turns curve exits the reference region, the graphical evaluator may fill the reference region with an unfavorable color, such as red (
The graphical evaluator 250 may also be operable to overlay the shoulder threshold 224 onto the torque gradient curve (
Once the connection 1 has been accepted, the torque-turns curve may or may not be added to the database 242.
As discussed above, the delta gradients 223 may be input separately from the reference curve database 242, thereby providing independent criteria for evaluating the connection. Alternatively, the delta gradients may be derived from the reference curve database 242 which may result in the criteria being dependent or independent depending on how the delta gradients are derived from the database.
Additionally, the graphical evaluator 250 may include a menu of options for the technician to configure the reference curves.
Additionally, the control system 206 may include a storage device 221, such as a hard drive or solid state drive, for recording the makeup data. The stored data may then be used to generate a post makeup report. Additionally, the graphical evaluator 250 may include a comments field for allowing the technician to enter notes for each individual connection and the notes may be recorded on the storage device 221 for inclusion in the report. Additionally, the technician may accept or reject the connection according to or in spite of the graphical evaluator's recommendation and the technician may enter an explanation for the acceptance or rejection in the comments field. Additionally, the graphical evaluator 250 may alert the technician of any detected anomalies in real time during the makeup using the alarm, such as by an audio alert and/or graphical alert.
Additionally, the graphical evaluator 250 may have the capability to plot selected connection graphs simultaneously—for example to spot trends in make-up performance which might be attributable to changes occurring in the machinery of the tongs (component wear, slow hydraulic leak, changes in temperature affecting hydraulics, etc.) or drift of the performance of the various sensors.
Alternatively, the tubular makeup system power drive may be a top drive instead of the tong assembly.
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the claims that follow.
| Number | Date | Country | |
|---|---|---|---|
| 61720426 | Oct 2012 | US |
