Automatic Coiled Tubing Injector Chain Management System

Abstract

The present application pertains to an injector chain control system for a coiled tubing unit. The system may comprise real time data received from sensors monitoring depth, pressure, force and other aspects of the well bore. The amount of hydraulic, electric, or pneumatic pressure allocated to the chain system may control both tension and traction system using the pressure as an indicator or trigger for the electronic feeding of information. A return feedback of the chain system may preset operating limits provided by well profile depths, pressures, temperatures, and/or composition of well contents in fluid, gaseous, and/or solid based. An injector chain system with or without a chain lubrication system may have a chain which is lubricated via an automated or manual system which can be triggered via a predetermined chain footage travel or timed interval, based on factors such a traction and/or tension pressure.

Description

FIELD OF THE INVENTION

This invention relates to the application of delivering a secured bearing to prevent the shearing of a roller bearing pin from rotational force exerted through the axis by a secured shaft through a bearing block attached to the rotational chain on equipment such as a coil tubing injector

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 was 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 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.

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.

DETAILED DESCRIPTION

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 1015% of life of the tubing could be gained due to ridding of undue traction and tension issues.

EMBODIMENTS

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 or without a chain lubrication system whereas the chain is 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 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 is 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.

Claims

1. An injector chain control system for a coiled tubing unit; comprised of: one or more sensors to monitor one or more of depth, pressure, and force of the well bore and transmit real time data to a processor;a chain system to control tension and an optional traction system, wherein the amount of a hydraulic, an electric, or a pneumatic pressure allocated to the chain system uses force, pressure, or both;wherein the chain system is configured to employ operating limits based on one or more of a well profile depth, a pressure, a temperature, and a composition of well content;an optional chain lubrication system wherein the chain lubrication system is configured to lubricate the chain system based on one or more of a predetermined chain footage travel, a timed interval, a traction pressure, or a tension pressure.

2. The injector chain control system of claim 1 wherein a pressure change is triggered based on one or more of the predetermined chain footage travel, the timed interval, the traction pressure, or the tension pressure.

3. The injector chain control system of claim 1 wherein the traction pressure, the tension pressure, or both is based on an adjusted injector data.

4. The injector chain control system of claim 3 wherein the adjusted injector data is based on one more of real time data from a well, an equipment degradation formula, an equipment degradation percentage, a coiled tubing attrition or a combination thereof

5. The injector chain control system of claim 4 wherein the real time data comprises injector data from previous jobs, from current exposure, or a combination thereof.

6. The injector chain control system of claim 1 wherein a loadcell data is provided to the processor in a form comprising hydraulic data, electric data , pneumatic data, or a combination thereof.

7. The injector chain control system of claim 1 wherein the system is configured such that a force is maintained from changing a range of values based on immediate changes in traction pressure to sustain a preset curve of change in tension pressure.

8. The injector chain control system of claim 1 further wherein at least one of the one or more sensors is configured to measure a chain length as a wear function, a chain length in an overloaded condition, or both, and wherein the system is configured to provide feedback for a logic device to indicate a maximum chain load, a maximum chain wear life, or both based upon an expected change in chain length.