Automatic coiled tubing injector chain management system

Abstract

The present application pertains to a method and system for coiled tubing injector chain management on a coiled tubing unit. Advances in tubing technology combined with lack of operator training have been detrimental to injector longevity. Optimizing chain and equipment life requires operating parameter control. This method utilizes feedback from loads on the injector chassis to adjust chain traction and tension to optimal levels to extend equipment life.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part application of pending U.S. Ser. No. 18 / 637,673 entitled “Automated Reel Tension” filed Apr. 17, 2024 which application is a continuation-in-part of U.S. Ser. No. 17 / 691,643 filed Mar. 10, 2022 entitled “Automatic Coiled Tubing Injector Chain Management System” which application claims priority to U.S. Provisional Application No. 63 / 158.946 filed on Mar. 10, 2021 all of which applications are incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates to the application of a method and system to extend the operating life on a coiled tubing injector.BACKGROUND AND SUMMARY OF THE INVENTION

[0003] Coiled Tubing is a mature technology utilized in the oilfield industry for decades. It is used for interventions in oil and gas wells and production tubing. Wireline units and snubbing units are alternative intervention methods. The most common application is frac plug milling and subsequent debris and fluid removal.

[0004] The Coiled tubing is feed 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.

[0005] Recent advances in tubing technology have made a significant impact on the field. Higher tensile strength tubing has been a positive to the industry in general by extending tubing life and allowing for completion of deeper wells. This higher tensile strength, however, has been detrimental to the operating equipment, specifically coiled tubing injectors. Methods to address these tubing technology advances and the impact on equipment will be beneficial.BRIEF DESCRIPTION OF THE FIGURES

[0006] FIG. 1 shows a coiled tubing path.

[0007] FIG. 2 shows the chains systems controlling the force on gripping blocks with sensor 110 monitoring the force and transmitting real time data to a processor 111 which may be on or near the coiled tubing unit or remote including in the control center for the unit.

[0008] FIG. 3 shows a method for adjustment made by an operator of a coiled tubing unit.

[0009] FIG. 4 shows a tension system using hydraulic or electric power to actuate a cylinder (108) known as a tension cylinder.

[0010] FIG. 5 shows an isolated view of the chassis

[0011] FIG. 6 shows direction of traction force relative to chassis.

[0012] FIG. 7 shows direction of tension force relative to chassis.

[0013] FIG. 8 shows an isolated view of the traction system with gripper blocks squeezing down on tubing.

[0014] FIG. 9 shows force measurement sensor location wherein sensor measures downward force.

[0015] FIG. 10 is complete injector assembly.DETAILED DESCRIPTION

[0016] 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. An injector drive system comprises the injector chassis, hydraulic motors, gearboxes, brakes, chains, sprockets, and hydraulic traction and tension cylinders. A representative coiled tubing path is shown in FIG. 1.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 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. Variations in injector chassis forces are considered to properly adjust the tension and traction pressure. Proper chain tension and traction are often critical to decrease wear on consumable parts such as chains (101) rollers (104), gripper blocks (105) and skates (102). The result is also 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. Recent advances in coiled tubing characteristics have impacted commonly understood operating parameters. Combined with reduced field knowledge, injector equipment has been adversely impacted. 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.Embodiments

[0021] 1. An injector chain control system for a coiled tubing unit; comprised of:

[0022] i) Real time data received from sensors monitoring load feedback on the injector drive system.

[0023] 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.

[0024] iii) Return feedback of the chain system to preset safe operating limits provided by drive system load feedback.

[0025] 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.

[0026] 3. The chain control system of embodiment 1; whereas force measurement sensor information is provided in either hydraulic, electric, or pneumatic form to provide for logic.

[0027] 4. 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.

Examples

embodiment 1

[0026]3. The chain control system of embodiment 1; whereas force measurement sensor information is provided in either hydraulic, electric, or pneumatic form to provide for logic.

[0027]4. 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.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part application of pending U.S. Ser. No. 18 / 637,673 entitled “Automated Reel Tension” filed Apr. 17, 2024 which application is a continuation-in-part of U.S. Ser. No. 17 / 691,643 filed Mar. 10, 2022 entitled “Automatic Coiled Tubing Injector Chain Management System” which application claims priority to U.S. Provisional Application No. 63 / 158.946 filed on Mar. 10, 2021 all of which applications are incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates to the application of a method and system to extend the operating life on a coiled tubing injector.BACKGROUND AND SUMMARY OF THE INVENTION

[0003] Coiled Tubing is a mature technology utilized in the oilfield industry for decades. It is used for interventions in oil and gas wells and production tubing. Wireline units and snubbing units are alternative intervention methods. The most common application is frac plug milling and subsequent debris and fluid removal.

[0004] The Coiled tubing is feed 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.

[0005] Recent advances in tubing technology have made a significant impact on the field. Higher tensile strength tubing has been a positive to the industry in general by extending tubing life and allowing for completion of deeper wells. This higher tensile strength, however, has been detrimental to the operating equipment, specifically coiled tubing injectors. Methods to address these tubing technology advances and the impact on equipment will be beneficial.BRIEF DESCRIPTION OF THE FIGURES

[0006] FIG. 1 shows a coiled tubing path.

[0007] FIG. 2 shows the chains systems controlling the force on gripping blocks with sensor 110 monitoring the force and transmitting real time data to a processor 111 which may be on or near the coiled tubing unit or remote including in the control center for the unit.

[0008] FIG. 3 shows a method for adjustment made by an operator of a coiled tubing unit.

[0009] FIG. 4 shows a tension system using hydraulic or electric power to actuate a cylinder (108) known as a tension cylinder.

[0010] FIG. 5 shows an isolated view of the chassis

[0011] FIG. 6 shows direction of traction force relative to chassis.

[0012] FIG. 7 shows direction of tension force relative to chassis.

[0013] FIG. 8 shows an isolated view of the traction system with gripper blocks squeezing down on tubing.

[0014] FIG. 9 shows force measurement sensor location wherein sensor measures downward force.

[0015] FIG. 10 is complete injector assembly.DETAILED DESCRIPTION

[0016] 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. An injector drive system comprises the injector chassis, hydraulic motors, gearboxes, brakes, chains, sprockets, and hydraulic traction and tension cylinders. A representative coiled tubing path is shown in FIG. 1.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 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. Variations in injector chassis forces are considered to properly adjust the tension and traction pressure. Proper chain tension and traction are often critical to decrease wear on consumable parts such as chains (101) rollers (104), gripper blocks (105) and skates (102). The result is also 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. Recent advances in coiled tubing characteristics have impacted commonly understood operating parameters. Combined with reduced field knowledge, injector equipment has been adversely impacted. 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.Embodiments

[0021] 1. An injector chain control system for a coiled tubing unit; comprised of:

[0022] i) Real time data received from sensors monitoring load feedback on the injector drive system.

[0023] 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.

[0024] iii) Return feedback of the chain system to preset safe operating limits provided by drive system load feedback.

[0025] 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.

[0026] 3. The chain control system of embodiment 1; whereas force measurement sensor information is provided in either hydraulic, electric, or pneumatic form to provide for logic.

[0027] 4. 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.

Examples

embodiment 1

[0026]3. The chain control system of embodiment 1; whereas force measurement sensor information is provided in either hydraulic, electric, or pneumatic form to provide for logic.

[0027]4. 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.

Claims

1. An injector chain control system for a coiled tubing unit comprised of:one or more sensors to monitor the force on a coiled tubing injector drive system and transmit real time data to a processor;a chain system to control injector drive system operating parameters wherein the amount of a hydraulic, an electric, or a pneumatic pressure allocated to the chain system is determined by calculations of the processor;wherein the chain system is configured to employ operating limits based on the force sensed on the coiled tubing injector drive system by the one or more sensors.

1. The injector chain control system of claim 1 wherein a pressure change on the chain system is triggered based on the force sensed on the coiled tubing injector drive system by the one or more sensors.

2. The injector chain control system of claim 1 wherein a traction pressure on the chain system, a tension pressure on the chain system, or both is based on processor calculations employing the force sensed on the coiled tubing injector drive system by the one or more sensors.

3. The injector chain control system of claim 1 wherein data from the one or more sensors is provided to the processor in a form comprising hydraulic data, electric data, pneumatic data, or a combination thereof.

5. The injector chain control system of claim 1 wherein the system is configured such that a the monitored force from the one or more sensors is used by the processor to calculate a traction pressure and tension pressure used on the chain system.

6. A process for adjusting an injector chain control system of a coiled tubing unit comprising:monitoring the force on a coiled tubing injector drive system by one or more sensors and transmitting real time monitored force data to a processor;employing the processor to calculate operating parameters to allocate to a chain system injector drive system based on the force transmitted to the processor; andadjusting operating parameters to the calculated operating parameters.

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