AUTOMATED REEL TENSION CONTROL SYSTEMS AND PROCESSES

Abstract

The present application pertains to an automated control system for controlling and adjusting reel tension on a coiled tubing unit. The system may comprise real time data received from one or more sensors, input by an operator, or calculated.

Description

FIELD OF THE INVENTION

This application relates to an automated reel tension control system useful on, for example, coil tubing equipment.

BACKGROUND AND SUMMARY OF THE INVENTION

Coiled Tubing is a relatively new technology for the oil and gas industry. It is used for interventions in oil and gas wells and production tubing. Previous to the introduction of Coil Tubing, Wirelining or workover rigs were used to complete similar operations. The most common application is deliquification, and the dispersement of fluids to a specific location in the well. Coiled Tubing has recently been used to assist in drilling operations.

The Coiled tubing is fed from a reel into the injector which effectively powers the tubing into the wellhead. The end of the coiled tubing string can be outfitted with numerous downhole tools including drill bits and other related drilling equipment. The “Gooseneck” is the angled piece on the injector which guides the tubing and allows a bending of the coil string to allow it to go through the injector. It is what guides the tubing from the reel and directs the tubing from an upwards angle and turns it into a vertical down position into the injector and through a Blow-out Preventer (BOP) Stack into the Wellhead. The Injector and Gooseneck are connected together and are suspended by a crane or similar lifted methods for operations.

Coiled tubing operators are tasked with a variety of manually adjusted settings during the course of a job. Maintaining the proper settings is often key to a successful, efficient, and safe job. Running the job properly may also result in extended equipment life. Even being off on one parameter can have a negative effect on job performance and equipment maintenance and longevity. High workload on operators often results in “rule of thumb” parameter settings that can lead to equipment and job process failures. Coiled tubing reel tension is one variable operator input during a coiled tubing job. The operator typically takes feedback from the operations to determine an amount of reel tension which tension is then only adjusted when the operator decides to make an adjustment.

What is needed are systems and processes to reduce the workload on the operator and/or ensure parameter settings are optimal. The present systems and methods meet that need as well as others.

The present application pertains to an automated system that takes discrete system feedback to continuously adjust reel tension to proper settings. Such feedback may comprise tubing direction, tubing OD, tubing wall thickness, tubing grade, position of tubing wrap on reel, visual, and/or well specific rigup. The system of the present application may take inputs such as tubing size, tubing wall thickness, tubing grade (tensile strength), well position (which determines how many wraps are on the reel), tubing movement direction (in-hole vs out-hole), and/or a specific arrangement to a given unit. In some embodiments the reel tension pressure is changed depending upon whether the tubing is going in-hole or out-hole even when other factors are the same or similar. A typical unit specific arrangement may include tubing reel dimensions such as reel core diameter and/or reel drive components.

A system is provided to take the inputs and/or the unit specific arrangement from the coiled tubing unit, process it through an on-board computer, and continuously adjust the reel tension setting to the proper setting. The system described here provides the necessary sensors and computer to provide the data for reel tension calculations. This advantageously reduces operator workload while ensuring parameter settings are optimized for the job and for reducing equipment maintenance. In addition, different manufacturers require different reel tension settings due to specific equipment configurations. An operator who has experience with other manufacturer's equipment may not set the reel tension properly when using new equipment. The present system will reduce or eliminate an operator's learning period when transitioning to unfamiliar equipment.

The reel tension control system described above may be incorporated into the control system. In this manner, one with a system as described here obtains the benefit of the reel tension control system. Formulas are determined in order to program the system to result in the proper settings. As described previously, inputs include, for example, tubing size, tubing wall thickness, tubing grade (tensile strength), well position which determines how many wraps are on the reel, tubing movement direction (in-hole vs out-hole), and unit specific arrangement. The unit specific arrangement will include tubing reel dimensions such as reel core diameter and reel drive components.

The systems may include sensors to provide real time readings, an operator input touchscreen/keyboard, and a PLC/PC system to receive the sensor signals, perform the unique calculations, and output signals to electroproportional valves and controls that adjust reel tension.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a coiled tubing path.

FIG. 2 shows the chains systems controlling the force on gripping blocks.

FIG. 3 shows a method for adjustment made by an operator of a coiled tubing unit.

FIG. 4 shows a tension system using hydraulic or electric power to actuate a cylinder (108) known as a tension cylinder.

FIG. 5 shows a reel for coiled tubing.

DETAILED DESCRIPTION

Injector Chain Control System

This invention is directed towards the industry dependence on Coil Tubing Injectors, specifically the control of the chain systems that rotate under either hydraulic, electric power to provide a set of rational gripper blocks to feed or pay tubing in or out of a well. The injector chain systems rotate around the chassis of the injector by means of a sprocket driven system that engages into the links of the chain forcing the chains to rotate via a track from the top to the bottom sprockets in and endless rotation. A representative coiled tubing path is shown in FIG. 1.

As shown in FIG. 2 the chain systems further control the amount of force directed into the tubing gripping blocks during in-hole and out-hole operations which is commonly known in the industry as Traction pressure. Hydraulic or electric forces push cylinders (103) outwards on to the injector skates (102) which in turn push against the rollers in the chain forcing the chain (101) outwards into a more elliptical path and thus increasing the force on the gripper blocks (105) thereby increasing grip on the tubing. Reversing the hydraulic or electrical forces will reduce the grip on the tubing.

As shown in FIG. 3 the method for this adjustment is made by the operator of a coiled tubing unit, using the adjustment of a valve to illicit the prescribed response that is needed for operations. Typically, the increase in traction pressure results in greater grip for the installed gripper blocks (105) on the tubing that traverses thru the injector via the chain (101) and a reduction in traction pressure results in lessoning the grip on the tubing that traverses thru the injector via the chain (101).

The tension system further controls the amount of force directed onto the chains (101) during in-hole and out-hole situations. The in-hole direction is the most critical direction due to the fact that the chain links can compress together or “bunch up”. This bunching up can cause catastrophic damage to the chain system. As shown in FIG. 4 the tension system uses hydraulic or electric power to actuate a cylinder (108) known as a tension cylinder. The tension cylinder uses that force to move the lower chain sprocket (107) away from the upper sprocket (106), to a load higher than the force generated on the chain in the upward direction thereby preventing a “bunching” of the chain during in-hole movements. The traditional method for this adjustment is made by the operator of a coiled tubing unit, using the adjustment of a valve to illicit the prescribed response that is needed for operations.

There is no current system in use that would allow an operator to consistently manage the chain system on a coiled tubing injector, running in both in-hole and out-hole operations. Adjustments are needed to the tension and traction pressures frequently and simultaneously when the tubing traverses to different depths in the wellbore. This can be due to changes in fluid pressure of the well, changes in wellbore drag and the mass of the tubing downhole. Variations in these conditions occur and sometimes all variations of these conditions may be considered to properly adjust the tension and traction pressure. Proper chain tension and traction are useful to decrease wear on consumable parts such as chains (101) rollers (104), gripper blocks (105) and skates (102) while maintaining enough traction as to avoid slipping of the tubing through the injector. When not adjusted with the proper tension and traction, these parts degrade considerably and can be a major cause of failure in injector heads. Avoiding down-time for maintenance is paramount in running an efficient coiled tubing job. Also, the operator has to divide their duties between spooling and unspooling a coil unit, observing key pressure indicating gauges, as well as mechanical gauges during operation. Removing the task of constantly adjusting the tension and traction pressures will alleviate the operator from such tasks, freeing the operator's attention to wellbore safety. Control of the chain system also improves the lifecycle of the coiled tubing. This is seen in wear in the tubing, and undue markings from over-traction and under-tension. The cost of the tubing is a company's greatest expenditure for a consumable item. An improvement of 10-15% of life of the tubing could be gained due to ridding of undue traction and tension issues.

The aforementioned system may employ data based on information from the well condition, the well position, and/or information about the wear of various components of the coiled tubing unit. In this manner tubing slip may be prevented as traction and tension may be continuously adjusted. The lubricating system may advantageously control the required volume of oil based on various factors such as, for example, chain type, linear chain speed, and oiling pump output.

The system is also advantageous because adjusted injector data may be employed. That is, the system may adjust for different injectors having different operating parameters. Additionally, the well conditions and tubing location may continually change the allowable control range. In this manner system adjustments, i.e., adjusted injector data may be based inputs such as wellhead pressure, forces on the tubing from the wellbore, and/or direction of travel, tubing load in the wellbore. If desired a loadcell may be employed to measure the tubing force and that data may also employed in determining the adjustment, if any, for chain tension and traction. A sensor may be employed to directly measure chain length and provide that data to the control system. The control system may also account for the tubing weight force on the chain that allows for elastic stretch. Machine learning may also be employed.

Embodiments Of Injector Chain Control

An injector chain control system for a coiled tubing unit; comprised of:

• • i) Real time data received from sensors monitoring depth, pressure, force and other aspects of the well bore.
  • ii) The amount of hydraulic, electric, or pneumatic pressure allocated to the chain system, to control both tension and traction system using the pressure as an indicator or trigger for the electronic feeding of information.
  • iii) Return feedback of the chain system to preset safe operating limits provided by well profile depths, pressures, temperatures, and composition of well contents; whether fluid, gaseous, or solid based.
  • iv) An injector chain system with a chain lubrication system where the chain may be lubricated via an automated or manual system which is triggered via a predetermined chain footage travel or timed interval, based on factors such a traction and/or tension pressure.

2. The chain control system of embodiment 1; whereas a pressure change is triggered via an input based on the logic system composed of the contents of embodiment 1.

3. The chain control system of embodiment 1; whereas traction and tension pressure are provided on data based off empirical data using a performance chart of said injector adjusted by real time data from the well, equipment degradation formulas or percentages, and/or coiled tubing attrition as it relates to previous jobs, and current exposure.

4. The chain control system of embodiment 1; whereas Loadcell information is provided in either hydraulic, electric, or pneumatic form to provide for logic.

5. The chain control system of embodiment 1; whereas a constant change in range of values based on immediate changes in traction pressure sustain a preset curve in change in tension pressure to maintain forces.

6. The chain control system of embodiment 1; whereas a sensing device measures chain length as a wear function or chain length in an overloaded condition and provides feedback for the logic device to indicate and notify of maximum chain load or chain wear life based upon expected increase in length.

Automated Reel Tension Control Systems

The present system pertains to an automated reel control system for coiled tubing. The system typically comprises one or more sensors to monitor one or more parameters such as tubing size, tubing wall thickness, tubing grade (tensile strength), reel geometry, well position (which determines how many wraps are on the reel), tubing movement direction (in-hole vs out-hole). There may be one or more sensors for each parameter or in some cases a sensor may be associated with more than one parameter. The sensors employed to monitor the parameter need not be automated. That is, in some cases the sensed parameter may be calculated based on other inputs or directly input by, for example, an operator. For example, tubing size, tubing wall thickness, tubing grade, and reel geometry may be operator inputs. Similarly, well position which determines how many coiled tubing wraps are on the coiled tubing reel may be a calculated parameter. The Data associated with the aforementioned parameters are transmitted in real time to an operably linked processor.

The processor is typically operably linked to an actuator configured to control reel tension. In this manner, the processor may calculate a proper reel tension based on the transmitted real time data associated with the parameters. The processor can then transmit a signal to the actuator to adjust tension on the reel.

The specific manner of how the actuator adjusts reel tension is not particularly critical so long as it is done reasonably accurately. In some embodiments, the actuator adjust reels tension using a hydraulic, an electric, or a pneumatic pressure. In other embodiments, the actuator comprises an electroproportional valve which receives the processor's signal and adjusts the reel tension. As described above, reel geometry is one parameter that may be employed by the processor in calculating a proper reel tension. Reel geometry may be sensed automatically or input manually by, for example, an operator. Reel geometry may include information about the reel shape, e.g., circular or elliptical, and reel size, e.g., diameter or other dimensions. Reel geometry also may include information about the various components on the reel drive. Any or all of these may be employed by the processor with the parameters above to calculate a proper reel tension.

If parameters are to be input to the processor then this may be accomplished in any convenient manner. In some cases, an operator input may comprise a touch screen, a keyboard and may include a monitor all of which, of course, are operably connected to the processor.

Embodiments of Automated Reel Tension Control Systems

1. An automated reel tension control system comprising:

• • one or more sensors configured to monitor one or more of tubing size, tubing wall thickness, tubing grade (tensile strength), reel geometry, well position (which determines how many wraps are on the reel), tubing movement direction (in-hole vs out-hole) and transmit real time data to a processor;
  • an actuator for controlling reel tension;
  • the processor operably connected to the actuator, wherein the processor is configured to calculate a proper reel tension based on the transmitted real time data and transmit a signal to the actuator to adjust tension on the reel; and
  • an operator input operably connected to the processor.

2. The system of embodiment 1 wherein the actuator adjusts reels tension using a hydraulic, an electric, or a pneumatic pressure.

3. The system of embodiment 1 wherein the actuator comprises an electroproportional valve.

4. The system of embodiment 1 wherein the processor further employs a reel core diameter, reel drive components, or both to calculate the proper reel tension.

5. The system of embodiment 1 wherein the operator input comprises a touch screen.

6. The system of embodiment 1 wherein the operator input comprises a keyboard and monitor.

7. The system of embodiment 1 wherein tubing size, tubing wall thickness, tubing grade, and reel geometry are operator inputs.

8. The system of embodiment 1 wherein well position is employed to calculate the number of coiled tubing wraps on the coiled tubing reel.

9. A process for controlling reel tension on a coiled tubing reel comprising:

• • transmitting data comprising tubing size, tubing wall thickness, tubing grade, reel geometry, well position, and tubing movement direction to a processor;
  • calculating a proper reel tension for a coiled tubing reel with the processor based on the transmitted data;
  • transmitting a signal comprising the calculated proper reel tension to an actuator configured to control reel tension; and
  • adjusting reel tension with the actuator to the calculated proper reel tension using the transmitted signal.

10. The process of embodiment 9 wherein the actuator is configured to adjust reel tension using a hydraulic, an electric, or a pneumatic pressure.

11. The process of embodiment 9 wherein the actuator comprises an electroproportional valve.

12. The process of embodiment 9 wherein the processor further employs a reel core diameter, reel drive components, or both to calculate the proper reel tension.

13. The process of embodiment 9 wherein tubing size, tubing wall thickness, tubing grade, and reel geometry are operator inputs.

14. The process of embodiment 9 wherein well position is employed to calculate the number of coiled tubing wraps on the coiled tubing reel.

Claims

1. An automated reel tension control system for a coiled tubing reel comprising: one or more sensors configured to monitor one or more parameters of tubing size, tubing wall thickness, tubing grade, reel geometry, well position, and tubing movement direction, and transmit real time data to a processor;an actuator for controlling reel tension;a processor operably connected to the actuator, wherein the processor is configured to calculate a proper reel tension based on the transmitted real time data and transmit a signal to the actuator to adjust tension on the reel; andan operator input operably connected to the processor.

2. The system of claim 1 wherein the actuator adjusts reel tension using a hydraulic, an electric, or a pneumatic pressure.

3. The system of claim 1 wherein the actuator comprises an electroproportional valve.

4. The system of claim 1 wherein the processor further employs a reel core diameter, reel drive components, or both to calculate the proper reel tension.

5. The system of claim 1 wherein the operator input comprises a touch screen.

6. The system of claim 1 wherein the operator input comprises a keyboard and monitor.

7. The system of claim 1 wherein tubing size, tubing wall thickness, tubing grade, and reel geometry are operator inputs.

8. The system of claim 1 wherein well position is employed to calculate the number of coiled tubing wraps on the coiled tubing reel.

9. A process for controlling reel tension on a coiled tubing reel comprising: transmitting data comprising tubing size, tubing wall thickness, tubing grade, reel geometry, well position, and tubing movement direction to a processor;calculating a proper reel tension for a coiled tubing reel with the processor based on the transmitted data;transmitting a signal comprising the calculated proper reel tension to an actuator configured to control reel tension; andadjusting reel tension with the actuator to the calculated proper reel tension using the transmitted signal.

10. The process of claim 9 wherein the actuator is configured to adjust reel tension using a hydraulic, an electric, or a pneumatic pressure.

11. The process of claim 9 wherein the actuator comprises an electroproportional valve.

12. The process of claim 9 wherein the processor further employs a reel core diameter, reel drive components, or both to calculate the proper reel tension.

13. The process of claim 9 wherein tubing size, tubing wall thickness, tubing grade, and reel geometry are operator inputs.

14. The process of claim 9 wherein well position is employed to calculate the number of coiled tubing wraps on the coiled tubing reel.