Uses of coiled tubing in petroleum well workover and drilling operations

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In the oil industry and along with the knowledge of petroleum engineering, several techniques have been advanced to facilitate drilling and well rehabilitation operations, among which the technique of using coiled tubing stands out. Coiled tubing is nothing more than a long metal pipe that normally ranges from 25 to 83 millimeters in diameter, the characteristic of being flexible facilitates the logistics of operations, as it can be wound on a large spool that can accommodate all the feet of pipe length.

Why is flexible piping necessary in the oil industry?

Normally in drilling operations are used drill pipes that do not have that flexible character as the coiled tubing has, however they are necessary for complex operations such as drilling deep wells, now for less complex well interventions such as change in the production tubing, drilling shallow wells, among other less complex interventions, coiled tubing is used.

One of the obvious reasons to delve into the reasons for the application and use of coiled tubing lies in the fact of being able to understand the benefits that coiled tubing provides in its application, since with the use of coiled tubing for example we can pump any fluid with ease without having to rely on gravity and with the advantage that since the tubing is flexible, such pumping can be directed to any part of the well.

As a drilling operations engineer I must also point out that the primary objective of being able to employ an engineering design that is successful, involves contemplating all operations that are economical, for this the choice is coiled tubing, as long as its use applies, that is why the use of coiled tubing is employed as an economical version especially in workover operations of wells.

Given the flexibility of coiled tubing ranging from 55 KPSI - 120 KPSI, it can be used in hydraulic fracturing operations of reservoir rock, as it can penetrate and locate the source rock to be fractured very easily, which could not be done with drill pipe.

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Why is coiled tubing especially used in downhole fluid circulation operations?

It could be said that circulation is one of the most common uses of coiled tubing, since when you want to maintain an imbalance in the well pressures you have to seek to circulate a gasified drilling fluid, and this is achieved effectively with coiled tubing.

Even this circulation works as a stimulation method, since if the well is dead, that is, there is a conventional mud in the well that is containing fluids such as gas and/or oil from the formation, that is, there is an overbalance, and you want to break this overbalance, the most effective way is to use the coiled tubing and lower it to the depth where the conventional mud is located, Pumping the gasified fluid inside the coiled tubing to displace the dense column of fluid or conventional mud and start producing oil, that is why it is said that the coiled tubing is very important for the stimulation of the production of an oil well when it is in an overbalance of pressures.

Conclusion

In relation to the use we can give to coiled tubing in relation to workover, rehabilitation and drilling operations of oil wells are the same that can be done in conventional operations where production tubing or drill pipe is used, everything will depend on the engineering and design study that is done to determine the feasibility in the use of coiled tubing.

References

COILED TUBING APPLICATIONS