Coiled tubing: a brief insight what it is and its uses.Feb 6, 2019
Undoubtedly, The oil and gas industry is recognized as one of the world’s most powerful and profitable sectors.
Within the very vast industry, a series of processes take place to bless us with tons of indispensable petroleum products.
However, these processes are usually hindered by more than a factor.
Coiled tubing, which provides a key solution to a wide range of these drawbacks.
Therefore, our focus will be on what the coil tubing method is, the composition of a coiled tubing unit and its advantages as well.
- Intro about The oil and gas industry to help understand what coiled tubing is
- The concept of well intervention
- What is Coiled Tubing?
- What is coiled tubing used for?
- How does coiled tubing work on site?
- What is a conventional workover rig?
- To conclude.
Intro about The oil and gas industry to help understand what coiled tubing is
Before we go through our main focus “what coiled tubing is?”, it is important to introduce you to the Oil & Gas industry and its most relevant concepts.
Oilfield also referred to as oil patch, is the industry associated with a sequence of operations that end up with the manufacturing of dozens of petroleum products.
Each operation is classified under one of the following categories:
- Upstream: this stage includes early processes of Oil & Gas exploration and extraction.
First, broad researches for underwater or underground Oil & Gas take place, which is Oil & Gas exploration.
Later on, wells are drilled into the targeted sites to recover the precious oil, known as the oil extraction process.
- Midstream: that includes activities such as transportation, storage, and processing of the extracted oil.
- Downstream: the stage including the processes of marketing the petroleum products and the distribution to the very end users.
Within the upstream primary stage, a series of problems frequently rise up and impacts the overall performance of the well which in turn cuts down its profitability.
These obstacles vary from a well to another most of the time.
But wells are usually encountered by problems such as failures of mechanical equipment, fluctuation of production characteristics, plugging and increases in injection pressure.
The concept of well intervention
To get over these problems, a number of solutions are considered to restore the well back to its full productivity. This is what referred to as well intervention methods in the Oil & Gas scope.
Nowadays, coiled tubing is increasingly resorted to as it affords a reliable and effective method for well intervention.
What is Coiled Tubing?
Physically, coiled tubing appears in drilling sites as a long metal pipe rolled over a huge reel.
The pipe is usually made of steel or special composites that gives it the adequate flexibility to be wound around the reel without fracture.
For the pipe diameter, it varies with respect to the dimension of the wellbore. However, it generally ranges from 25 to 85 mm to fit in the well hole.
Along with the main component, the coiled tubing unit is accompanied by three more modules:
Module 1: the injector head
This component is meant to do the mission of giving in the tractive effort necessary to run the coiled tubing string and retrieve it back when work is done.
Module 2: the control cabin
The cabin attached is responsible to keep the whole operation under control and monitored. It also customizes the pipe to suit the required task.
Module 3: the power pack
The final part is concerned with generating the power to run all other parts. Also, it is worthy to know that power involved in the process can either be pneumatic or hydraulic.
The capacities and dimensions of the former modules are essential to determine the length and diameter of the coiled tubing string and its capabilities to achieve the optimum performance.
What is coiled tubing used for?
As mentioned earlier; coiled tubing serves as a reliable method for well intervention.
That is due to its functionality in several potential drawbacks during the upstream stage in the oil patch.
Coiled tubing provides effective solutions for problems associated with processes such as:
- Rock fracturing
- Production tubing
- Low bottom hole pressure drilling
- Wellbore cleanout
- Nitrogen kickoff
- Sand control
- Mechanical isolation
- Tube Logging & perforating
Coiled tubing pipes are also privileged to function so properly with the same efficiency on both offshore and onshore oil well locations.
How does coiled tubing work on site?
Basically, coiled tubing can reach considerable depths in oil wells.
Actually, the coiled tubing string can extend the long metal pipe to depths up to around 15000 feet.
Saying that, coiled tubing is recognized as a very effective solution for deep wells.
The question here is as follow: how does coiled tubing interfere and work out problems in Oil & Gas well locations?
Simply, the steel pipe first gets unwounded from its reel. Soon after that, it gets free to be injected into the existing production string and then inserted inside the well.
What is a conventional workover rig?
Having been a new technique within the Oil & Gas industry, former conventional methods used to be in use in order to overcome well-associated problems.
Workover rigs used to take over before coiled tubing got introduced to the huge industry.
The drilling-rig-like workover rig was a little smaller but required no additional pressure control units.
It’s typically used to restore components such as pump/production tubing and the sucker rod string from the well.
Also, it functioned well when it came to establish full cleaning to the wireline and repair various equipment inside the well.
Coiled tubing Vs. Conventional workover rig.
However, there was a serious disadvantage for using the conventional workover rig. Once put in use, the workover rig required other processes to be stopped.
Immediately, the production of the well reaches zero, which in turn impacts the well profits in the long run.
And this is exactly what gives the coiled tubing method a key advantage over the conventional workover rigs.
Coiled tubing technology is widely selected instead since it is equipped to work while production is ongoing even in cases of high-pressure wells.
In more explanation, operations such as the replacement of broken equipment and cleanout of the wellbore take place with no need to stop the production process.
Eventually, this helps to maximize the duration of the well to be in production. As a result, profits can continue to be generated without any fears of compulsory stoppages for well maintenance.
The Oil & Gas industry is globally recognized to present the power of economy and development.
Therefore, shareholders and employers give special attention to maximize the productivity of their oil wells to generate optimum revenues.
Like any other industry, problems within operation and production of oil and other petroleum materials rise up and hinder the work progress.
Hence, engineers have focused their efforts to come up with solutions to overcome these problems.
A short time ago, coiled tubing technology was established to introduce a solution that affords the employer with reliability, effectiveness, and cost-efficiency.
The new method continues to grab more reputation within the industry and even started to be selected over the conventional workover rigs.
Moreover, technological advances are currently to be integrated into coiled tubing units such as the internet of things to boost the system with more functionality and enhanced performance.
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