the 5 most common coiled tubing applications worldwideNov 26, 2019
Have you ever heard or came across the term “coiled tubing”? and if so, do you know what is it? what does it mean?
In the oil and gas industry, you always come across specific words among its different terminologies.
One of these important terminologies is “coiled tubing”.
When you search about coiled tubing you find various common terminologies always repeated.
Terminologies such as: “coiled tubing units”, “Coiled tubing applications”, “the difference between wire-line and coiled tubing” and a lot more.
What exactly is coiled tubing? how important it in the oil and gas industry? and how did it start?
What is coiled tubing?
Simply put, the term “Coiled tubing” refers to flexible steel tubes.
They’re usually in the range of “1” to “2” inches in diameter.
And its length may exceed several thousand feet.
They are rolled on a large roller which is driven by hydraulic or electrical methods.
The installation of equipment related to the coiled tubing in the well is called a bottom hole assembly.
It ranges from a small chemical pump to highly complex recording installations.
The main component of Coiled Tubing is the injection head.
Below the injector head is the filler area.
The filler area contains a rubber gasket that isolates the well pressure from the outside.
Finally, the unit is provided with a conventional set of explosion-proof barriers.
These explosion-proof barriers help close the well when there is a risk of leakage or even cutting pipes.
In this case, it closes the well until controlled by drilling fluids.
The history of coiled tubing.
“The origins of continuous-length, steel-tubing technology can be traced to engineering and fabrication work pioneered by Allied engineering teams during the Second World War.”
“Although the initial development effort of spoolable steel tubulars was reported to have occurred in the early “1940s”, the first concept developed for use of continuous-length tubing in oil/gas wellbore services can be found in “U.S.“
As you can see coiled tubing goes way back in time, of course, it’s not the same since it was first introduced to the industry.
Coiled Tubing has developed over the years so we can finally have the coiled tubing of today.
“In “1962”, the California Oil Co. and Bowen Tools developed the first working prototype “continuous-string light workover unit” for use in washing out sand bridges in “U.S.” Gulf of Mexico oil/gas wells (Fig. 3)”
It seems that the “U.S.” mainly has the lead in coiled tubing development over the years and in introducing it to us in the modern look.
Importance of Coiled tubing.
Before we get into the importance of coiled tubing we need to understand where does it’s importance comes from?
The importance of anything related to the oil and gas industry is coming from how majorly important is it.
Petroleum is considered the main energy source in the world.
It’s a crucial key in the operation of a lot of other important industries.
So it’s no surprise that everything related to this industry is as important as the industry itself.
And that is why coiled tubing is notably valuable.
“Coiled tubing is used as a cost-effective solution for numerous well work and intervention applications with the key advantage of the ability to continuously circulate through the tubing while utilizing the coiled tubing pressure control equipment in treating a live well.”
Coiled tubing techniques are relatively new in the field of well operations.
It has occupied a rapidly advanced position in this field and its multiple uses ranging from simple pumping operations to drilling operations of vertical and directed wells.
These pipes are used for interference in wells or even as production pipes for gas wells.
Coiled tubing technology has replaced many wireline processes such as paraffin removal, well sampling, electrical and nuclear recording, and installation of packers.
The main advantage in the coiled tubing of the line is the possibility of pumping chemicals or cement into the well as it is suitable for wells with high inclination angles and horizontal, unlike the line.
Global Coiled Tubing status.
According to “markets and markets”, the coiled tubing market is rapidly increasing and expanding around the world:
“The “North American” region remains the largest market for coiled tubing, followed by “Europe”, “Asia-Pacific”, and the “Middle East”.
The recent shale gas developments in the “U.S.” have pushed explorations activities in the region, thereby increasing the market.
The “Middle East” and “Africa” markets continue to be a key growth area due to the increasing demand for innovative technology in terms of oil & gas application, which is backed by new investments.
The development of new fields in the Middle Eastern and African region also provides a thrust, thereby driving the coiled tubing market in those regions.”
Coiled Tubing Applications
coiled tubing is indeed the future, agrees also with this “grand view research”:
“Increasing operating costs for extracting oil from existing wells and the regeneration of matured oil wells are the major factors for the growth of various oil recovering techniques.
In addition, the rise in shale gas projects and development in other unconventional resources is also anticipated to drive the market growth.
Declining oil & gas production from the existing wells is expected to boost the market in the next eight years.”
There is a large-scale range of operations on the site that makes good use of coiled tubing such as:
One of the most common uses of Coiled Tubing is to prevent the flow of hydrocarbons from the well to the surface.
This prevention happens by using the weight of the drilling fluid column (hydrostatic pressure) that requires lifting after completion of drilling or repair.
This is done by pumping gas (often nitrogen) down the well to displace the drilling fluid, allowing oil or gas to flow to begin production.
The approach of ever-increasing sizes of coiled tubing requires that nitrogen pump rates for each well be considered with some care.
Too high a pump rate can form a nitrogen buffer that will not let formation fluids to enter the wellbore.
Also, too low of a pump rate will result in an inefficient lift.
If any of these extreme cases happens it will result in extended job times, unnecessary use of nitrogen.
Then it will not unload enough fluid to allow the well to flow.
Then the fluid dynamics and associated forces need to be modeled at the job planning stage.
This one is a very important and crucial application for coiled tubing.
Such as acid pumping to open the pores of limestone layers, cement pumping, or chemical washing of wells.
Coiled Tubing ranks high in the implementation of these operations.
This is where it is characterized by the speed of installation and landing, which reduces the time of operations significantly.
Nitrogen lifting is used to reduce the hydrostatic pressure of the column to induce production after the closure of the well or its intervention activity.
What is particularly important in pumping applications is the pressure cycling effect on coiled tubing fatigue life, and the susceptibility of coiled tubing to collapse pressure.
Cleaning wellbores is one of the most common coiled tubing applications.
However, removing the fill from wells with low bottom hole pressures can be challenging.
This is particularly if wells are completed with smaller diameter production tubular which significantly reduces circulation flow cross-section and choke flow.
Of course, there is the conventional solution to overcome excess hydrostatic pressure and it’s to lessen the hydrostatic head by including nitrogen to reduce fluid density.
However, sand vacuuming technology using a concentric coiled tubing with a downhole jet pump is an alternative technique for removing fill without placing a hydrostatic load on the reservoir.
This use was developed to replace the traditional drilling methods.
It’s characterized by easy landing and lifting from the well tripping in and out, where many of the links are untied and disassembled in the case of ordinary drilling.
This application has many advantages that are very beneficial to the process.
It’s underbalanced drilling, managed pressure drilling and this is not exclusively.
Coiled tubing provides continuous use of hardwired telemetry and conduits Fully contained well pressure Small footprint and greater mobility Quicker trip times.
Drilling in the case of Coiled Tubing is carried out by a turbine engine that works by compressing the drilling fluid to move the ileum.
Logging and perforating
Usually, this process is done using conventional wireline equipment.
But in horizontal wells, it is difficult to complete the task of registration using wireline techniques.
These techniques depend on gravity to lower the equipment.
Therefore, in this case, coiled tubing is used.
As the rigidity of the pipes allows pushing into the well without relying on the weight of the equipment.
A type of Coiled Tubing is being developed.
It includes cables to transmit the electrical signal to and from equipment under the well.
Circulating nitrogen gas through the workstring will make production logging of low-pressure wells carried out effectively.
This process creates both the necessary formation drawdown and lift to bring returns to the surface.
As for perforating, conventional or pressure activated perforating guns can be run on coiled tubing.
However, the tools used for shear pin release should not be used.
The resulting shock wave from firing the guns without any trouble can generate force to shear the largest of any conventionally rated pins.
Coiled Tubing is used as a production pipe in gas wells.
It is lowered either inside the production pipe or inside the casing pipe directly.
Due to the small diameter of the Coiled Tubing pipes the gas rushes at a high speed.
In this case, raise the water to the surface so that it does not accumulate in the well and cause the flow to stop (kill the well).
The oil and gas industry is an essential pillar in the world economy.
It changes countries’ mindsets, especially Petroleum exporting countries.
Most of them have developed techniques in the science of oil extraction.
They also exploited the expertise and skills in this field pretty well.
These techniques include by default “coiled tubing”.
As you can mark here the future of coiled tubing is remarkably encouraging.
“With the high demand for energy in the African, Middle Eastern, and Asian regions, there has been an increase in exploration activities.
This has enhanced the coiled tubing market, which is estimated to grow and reach approximately “$4.4” Billion by “2020”, at a CAGR of “6-7%” from “2015” to “2020.“
The previous coiled tubing applications are not the only examples of how significantly important coiled tubing is.
These are only some of the most common ones, not all of them.
You can recognize how much progress is happening in the oil and gas fields.
The whole world is moving forward in a lightninglike speed, and not just in this industry.
So, the train is a non-stop, either you’re on it or you’re far behind.