Coil Tubing?

Coil Tubing During Oil and Gas Operations

Understanding Coil Tubing

The world of oil and gas operations is filled with innovation, and none is as versatile and invaluable as coil tubing (CT). But what is coil tubing, and what makes it an increasingly popular topic in the industry? The Complete Guide to Coil Tubing: Applications in Drilling, Completion & Intervention Operations This guide will cover everything you will need to know about coil tubing and its numerous applications for drilling, completion, and intervention operations.

✔Coil tubing is a long length of small-caliber tubing that has been wound on a reel, it is usually constructed out of steel or composite material. Unlike traditional jointed tubing, for which there are connections (screwed, flanged etc.) between consecutive, individual pieces, coil tubing allows for a seamless deployment and retrieval which is beneficial for many oilfield usages.

✔Coiled tubing is not only known for its production speed but also its strength.

✔Tubing: The main structure, often constructed from high-strength steel or composite materials. This type of pipe is available in different diameters and wall thickness to suit different wellbore environment and field requirements.

✔Reel: Coil tubing is stored on a Large drum or reel for efficient transportation and deployment.

✔Injector Head: The coil tubing is pulled from the reel and passes through an injector head at the wellsite, which manages its in-and-out movement as well as provides tension and support for the tubing.

✔Downhole Tools: Various downhole tools are used to execute the coil tubing operations, with specialized fishing tools, milling tools, and wellbore cleanout tools being deployed through the tubing as needed for the well intervention.

Applications of Coil Tubing in Oil and Gas Industry

1. Well Intervention

Well intervention operations comprise a large part of coil tubing application, which includes:

✔Well Cleanouts: Cleansing of debris, sand or paraffin accumulation blocking production

✔Scale Removal: Remove scale (chemically or mechanically).

✔Sand Control: Handling sand production challenges.

✔Hydraulic Fracturing Support: Injection of treatment fluids to deploy in the reservoir to increase its permeability.

2. Drilling and Completion

Similar to conventional drilling tools, coil tubing can also be utilized as a drilling and completion tool, particularly in slim hole and extended-reach wells, in instances where conventional drilling tools are either unfeasible or prohibitively expensive.

✔Coil Tubing Drilling (CTD): Re-entry drilling, and sidetrack drilling for entry to more reservoirs.

✔Underbalanced drilling (UBD): Enables operators to drill without harming the reservoir.

✔Cementing Operations: Properly placing cement plugs and liners.

3. Production Enhancement

Coil tubing is used by operators to increase well productivity and increase well life using various methods:

✔Matrix Acidizing: Injection of acid into the formation to remove scale and improve flow path.

✔Nitrogen Signatures: Enabling well to produce by treating with nitrogen to lift fluids.

✔Gas Lift Optimization: It allows the operation of gas lift gas lifted wells for more recovery.

4. Plug and Abandonment (P&A)

Examples of how a coil tubing is utilized towards well decommissioning include the deployment or installation of cement plugs or mechanical barriers which seal the wellbore in a permanent manner. This will allow for safe and environmentally compliant abandonment of the obsolete wells.

Advantages of Coil Tubing

1. Versatility

According to Baker Hughes, coil tubing can achieve multiple tasks during a single well intervention, making it one of the most versatile tools available in the oilfield.

2. Cost-Effectiveness

Lowers operational costs with the removal of classic workover rigs.

Reduces well downtime, enhancing production efficiency.

3. Greater Safety and Efficiency

Reduces personnel exposure to hazardous operations

Reduces well control risks through its capability to keep control of pressure.

4. Monitoring and control in real-time

Downhole sensors present in current coil tubing systems allow for real-time information for pressure, temperature, and flow rates to maximize well productivity.

Three challenges and limitations of coil tubing

Coil tubing has several advantages, but also there are some challenges, such as:

✔Limited Reach Extended Wells: The weight and tendency of coil tubing to buckle both limit its reach horizontally.

✔Tiredness and Wear: Continuous flexing and unbending cause metal fatigue which needs regular checks and replacement.

✔High Initial Costs: The expense associated with the equipment and technology used in coil tubing operations can deter some companies.

Trends in the Innovation of Coil Tubing Technology

With new technologies comes new developments that make coil tubing better:

✔Advanced materials: High-strength and corrosion-resistant materials that enhance tubing life.

✔Automated Injector Heads: Improving accuracy while minimizing risk.

✔Intelligent Coil Tubing: Utilizing AI and machine learning technology to increase performance

Conclusion

Coil tubing is a revolutionary development in well intervention, completion and production enhancement. Because of its cost-effectiveness, efficiency, and safety, it is a recommended equipment for modern oilfield operations.

With the advancement of technology in the market, coil tubing will remain an integral part of the solutions to maximize the efficiency of reservoir management, enhance recovery rates, and help in extending the life of oil and gas production.