Our Wiki pages provide users with insight and information on both Coiled Tubing and Coiled Line Pipe.

Wiki: Coiled Tubing


Well intervention involves several different types of operations performed on a well throughout its lifetime from drilling to completion. Typically performed to extend the life of producing wells, well interventions are conducted using either workover rigs, coiled tubing rigs, wireline, and fracturing fleets, among others.

Utilizing coiled tubing (CT) allows operators to have the most flexibility to perform a variety of these well interventions. Examples of such interventions performed with CT are open-hole drilling, annular fracturing, plug milling, acidizing and stimulation, cementing, logging, cleaning, fishing, and gas lifting.


Coiled Tubing is a long continuous steel pipe used to perform well completion, well intervention or workovers on a live well. During these processes, different types of fluids are pumped into the Coiled Tubing to operate and complete both onshore and offshore applications. Often Coiled Tubing has an outside diameter often ranging from ¾ – 5 ¼ inch and is typically wound on a large reel or installed on a Coiled Tubing unit reel.


Coiled tubing (CT) drilling is a type of well drilling operation which employs continuously milled coiled tubing strings, as opposed to traditional jointed pipe. The CT string is equipped with an electronic line (e-line) cable installed inside the coiled tubing. This is to guide the bottom hole assembly (BHA) for deviated and horizontal well deviations. Although not prevalent in North America, coiled tubing drilling is the preferred method for drilling wells in the Middle East and certain areas of Canada, where open hole production is feasible.

There are several benefits to coiled tubing drilling. Primarily, it is a cost-effective alternative to drilling rigs, due to the smaller footprint and reduced workforce needed by a CT rig. It The use of continuous length CT makes it faster and safer than traditional drilling rigs. CT eliminates the need to connect jointed pipe on surface, which allows for faster trip times from surface to target depth. It also reduces close proximity of the field crews to an open well head, which is a risk associated with traditional drilling methods.

Since CT drilling is performed with the well in an underbalanced condition, the amount of formation damage is much less since no kill mud is used. The underbalanced condition also enables partial production during the process of the well being drilled, allowing for earlier production times for the well. The live production during CT drilling also allows for a real time evaluation of the well’s production as it is being drilled. By evaluating the well’s production in real time, operators are able to gain some valuable insight as to the productivity of the formation and make well course adjustments or terminate drill plans should production be below expectations.

With these advantages, coiled tubing drilling has been the first choice in drilling wells in the Middle East. When compared to traditional methods, the speed, efficacy, and safety of coiled tubing drilling remains unparalleled and will continue to be the preferred method of intervention in the area.


Coil tubing operators, or CT service companies, perform different types of well interventions as needed by Oil and Gas (O&G) well operators. Coiled tubing has a wide range of applications, such as CT drilling, milling, annular fracturing, jetting, acidizing, cementing and gas lifting to name a few.

CT rigs have the flexibility to work across low to high pressure shale formations, with the added benefit of faster operations and smaller footprint, providing an economical service overall to O&G operators. Using coiled tubing (CT) rigs as opposed to workover rigs, well interventions are safer, more cost-effective, economical and faster to accomplish. 


Coiled Tubing was first developed during the Second World War for Operation PLUTO (Pipe-Line Underwater Transportation of Oil).


Coiled Tubing strings are made from multiple flat cuts of hot rolled sheet steel, called master coils. These master coils are then placed into a mill that turns the flat sheet into a continuous rolled tube. From there, the rolled tube is formed into a long continuous steel pipe with lengths that can go for miles.

During the milling process, several tests are performed on the tubing. Eddy-current, laser micrometer (OD measurements) and UT (wall thickness) are data logged during milling. After the string is milled, it is rolled or installed onto a shipping spool. From here it goes through a series of mechanical and integrity tests including tensile testing, flattening testing, metallographic examination, and hydrostatic testing. Finally, the string is purged of fluids and inhibited for corrosion and installed onto a Coiled Tubing unit where it becomes operational ready.


There are only a few Coiled Tubing Manufactures in the United States, one of those being Global Tubing. Global Tubing’s manufacturing facility is located in Dayton, Texas. Global Tubing can produce outside diameter sizes that range from 0.750 inches (19.1 mm) to 5.000 inches (127 mm) with wall thicknesses from as small as .087 inches (2.00 mm) to as large as .337 in (8.6 mm). Global Tubing’s proprietary steel chemistry, experienced manufacturing and technical personnel, state-of-the-art mill technology and digital control systems deliver consistently higher quality products. Global Tubing also has several service center locations:

1. Dayton, Texas, USA (Manufacturing Facility and Service Center Headquarters)
2. Houston, Texas, USA (Forum Energy Technologies Office)
3. Midland, Texas, USA (Service Center)
4. Smock, PA, USA (Service Center)
5. Red Deer, AB, Canada (Service Center)
6. Grande Prairie, AB, Canada (Service Center)


Coiled Tubing Unit (CTU) – Equipment consisting of components which usually include a Control Cabin, Coiled Tubing reel, and Coiled Tubing, Injector Head, Goose-neck, Power Pack, and well control components.

Coiled Tubing Reel – Component of Coiled Tubing unit used to spool string. Includes level-wind guides tubing for efficient spooling; can be mounted on CTU or trailer.  It can also be connected to fluid pumps and/or nitrogen pumps.

Power pack – System that provides power to the Injector, BOP’s, Reel, and Control Cabin. Also provides back-tension during operations. Systems are available in either hydraulic or electric-over-hydraulic.

Control Cabin – located behind a Coiled Tubing reel on a CTU, or as a separate unit in offshore operations, a control cabin houses all the controls necessary to operate a Coiled Tubing unit

Injector Head – Facilitates the entry of a Coiled Tubing string into the wellhead stack, regulates direction (run in hole or pull out of hole), and speed of the string. It is controlled by the operator in the control cabin with the use of a closed loop hydraulic system.

B.O.P.’s (Blowout Preventer) – Used in case of emergency to maintain well control.
1. Main BOP – Consists of: Slips, Pipe, Shear, and Blind
2. Combo B.O.P. – Used in addition to a regular B.O.P., combines Shear & Blind and Pipe & Slips

Fluid Pumps – Pressurize fluid that is pumped down Coiled Tubing string, usually in a tandem configuration.

Nitrogen Pumps – supply Nitrogen gas to Coiled Tubing inlet, either to pump pure nitrogen for lifting operations, or nitrified fluid in commingled operations. Can efficiently purge Coiled Tubing dry.

Crane – Holds up injector and riser assembly. Commonly contracted to a 3rd party company. Cranes may not be required for some specialized Coiled Tubing rig-ups, such as automatic mast Coiled Tubing units or Tower set-ups.

Flowback Equipment – connected to the Christmas tree as an outlet for produced fluids during operation. Used to control the backpressure / effective wellhead pressure for specific Coiled Tubing operations.


1. Able to perform operations without killing the well. In a conventional workover operation, the well needs to be killed before the Coiled Tubing operation can be safely performed. Coiled tubing jobs can be performed with the live well in a balanced (barrel-in-barrel-out) operation.

2. Formation Damage is minimized

3. Mobility – Coiled Tubing rig up and rig down can be performed in a day whereas, workover rigs can take up to a week to rig up and down

4. Time – service time is reduced significantly compared to joint tubing since Coiled Tubing is continuous and has no connections to make or break

5. Safety – with reduced manual pipe handling, safety is improved for crews and personnel.

6. Overall cost – Coiled Tubing is more cost-efficient per hour because of the increase in efficiency, and workover duration is drastically reduced.


Millout / Drillout
Nitrogen Lifting
Annular Fracturing
Zonal Isolation / Sand Control
Tubing Conveyed Perforation
Acid Stimulation


SMARTaper – Global Tubing’s patented Coiled Tubing technology which eliminates bias-weld fatigue spikes for longer running lengths. SMARTaper increases horizontal reach and adds strength in high-fatigue zones while managing the overall weight of the Coiled Tubing strings.

DURACOIL – technically advanced, cost-efficient Coiled Tubing for service in challenging downhole environments. DURACOIL has been tested to improve tubing fatigue life, predictability and resistance to abrasion, , and able to perform exceptional in high-pressure environments

Trends – as well depth begins to increase, so does the complexity of the Coiled Tubing string design. Advancements in bottomhole assemblies / tools, chemical additives and friction reducers that reduce helical buckling

Wiki: Coiled Line Pipe


Coiled Line Pipe is a long continuous steel pipe used for crude oil, diesel, gasoline fuel or natural gas transfer. Typical uses include flowlines, tiebacks, risers, chemical injection and umbilical systems in buried, above-ground and subsea installations.


Coiled Line Pipe was first developed during the Second World War for Operation PLUTO (Pipe Line Under the Ocean). It delivered fuel under the English Channel to supply the Allied Forces during the invasion of Normandy. The first installation was September 22, 1944 between the Isle of Wight and Cherbourg, France.

The development split into different groups following the successful WWII application:

  • Coiled Line Pipe (API 5LCP)
  • Flexible Steel Reinforced Pipe (API 17J)
  • Jointed and Coiled Steel Pipe (ASTM Grade B and API 5L)


Coiled Line Pipe is made from multiple flat cuts of hot rolled sheet steel called master coils. These master coils are slit into thinner members called strips to customize the final outside diameter. The strips are joined together using bias welds (skelp end welds), then fed into a pipe mill that turns them into a continuous rolled tube. From there, the rolled tube is welded and sized into a long continuous steel pipe with lengths that can span multiple miles.

During the milling process several inspections and tests are performed. Eddy Current (EC / ET) and Ultrasonic (UT) non-destructive testing methods are deployed per industry standards to ensure homogeneity in the longitudinal weld, bias welds and base material. Mechanical testing (tensile, hardness, flattening / flaring) is performed to ensure compliance with industry standards and customer requirements.

After milling and inspection, it is installed onto a shipping spool to accommodate the lengths required by the customer. Hydrostatic testing, drifting and a nitrogen purge ensure that the pipe is ready for operation.


There are only a few Coiled Line Pipe manufactures in the United States, one of those being Global Tubing. Global Tubing’s manufacturing facility is located in Dayton, Texas. Global Tubing can produce outside diameter sizes that range from 0.750 inches (19.1 mm) to 5.000 inches (127 mm) with wall thicknesses from as small as .087 inches (2.00 mm) to as large as .337 in (8.6 mm). Global Tubing’s proprietary steel chemistry, experienced manufacturing and technical personnel, state-of-the-art mill technology and digital control systems deliver consistently higher quality products. Global Tubing also has several service center locations:

  1. Dayton, Texas, USA (Manufacturing Facility and Service Center Headquarters)
  2. Houston, Texas, USA (Forum Energy Technologies Office)
  3. Midland, Texas, USA (Service Center)
  4. Smock, PA, USA (Service Center)
  5. Red Deer, AB, Canada (Service Center)
  6. Grande Prairie, AB, Canada (Service Center)


Installing GT Coiled Line Pipe is very much the same as normal carbon steel stick pipe when it comes to welding, coating repairs, burial and pre-commissioning.  However, despite all those similarities, the deployment of Coiled Line Pipe will be a similar experience for our clients and installation contractors to the installation of a flexible composite pipe product.   Global Tubing will collaborate with the installation contractor to ensure they have all the support and information necessary for a safe and successful pipeline installation from planning through execution.  Trained technicians will be onsite to operate the spooling equipment and assist the contractor through the entire process.

The basic concept for deploying Coiled Line Pipe is simple.  The spool is loaded into a spooling unit, the pipe is threaded through a straightener, and another piece of construction equipment pulls the pipe from the spool and down the right of way.  Once the pipe is on the ground, it can be handled and roped into the ditch in the same manner as stick pipe.


Global Tubing (GT)provides an excellent alternative to conventional 40ft double random length line pipe. By removing critical path items such as joint welding, X-ray inspection, heat treat and field joint coating from the field process, Global Tubing’s coiled line pipe technology greatly reduces installation times and the associated costs with large installation crews.

Global Tubing’s Coiled Line Pipe (CLP) is available in outside diameters up to 5 inches and a range of wall thicknesses that can be utilized in applications with pressure ratings beyond 15,000 psi for flowlines and pipelines, chemical injection lines, or umbilical applications.

The Coiled Line Pipe Advantage:

    • Depending on pipe size, almost a mile of pipe can be shipped on our standard shipping spools and installed without a single pipe-to-pipe weld.
    • Flexible deployment options are available such as direct lay from the shipping reel or consolidation onto larger carousels and vertical reels.
    • State-of-the-art 3-Layer Polyethylene (3LPE) 3-Layer Polypropylene (3LPP), or abrasion resistant overlay (ARO) coatings provides unrivalled protection for the pipeline during installation and for its design life.
    • Long, continuous pipe lengths can be utilized in directional bore pulls or crossings for quick and less risky deployment.
  • Coiled Line Pipe can be deployed in very harsh environments as qualification testing shows feasibility at temperatures as low as -58°F (-50°C). Global Tubing’s ISO and CSA compliant three-layer coating systems provide cathodic shielding, corrosion resistance and protection from rough terrain during installation and service.
  • Long lengths provide installation with less consolidation welds.
  • Coiled Line Pipe is compatible with other pipe systems, such as 40 foot (12 meter) API 5L joints.
  • For instance, when using 40 foot joints in tight areas with standard elbows and flanges, longer lengths of coiled linepipe (1000 feet+)  of the same grade and geometry can be directly butt welded to 40 foot joints and end connections
  • Continuous coating options using FBE/ARO, FBE/Polyethylene or FBE/Polypropylene alleviate the need for coating repairs on each joint of pipe.  Potentially the distance could be over 1000 feet between butt welds and coating repairs
  • Continuous OD makes this application ideal for pull through applications where a laydown distance equal to the the pull through is not necessary.  A reel of coiled linepipe and straightener can be located at the entrance to the pull through and a very small footprint is needed to deploy long lengths of API grades such as X52 with standard geometries and continuous coating.
  • The same would apply for sensitive areas such as marshland where the pipe can be deployed from a barge either by pulling with a cable, or unreeling and laying the pipe down as it is unreeled from the barge.


  • Flowlines
  • Tiebacks
  • Risers
  • Fuel Transfer
  • Chemical Injection Line
  • Methanol Injection Line


  • Use in applications traditionally utilizing API 5L jointed steel pipe
  • Utilizing higher strength grades for catenary and riser applications
  • Replacing failed composite lines with a more tried and tested material like steel

Certificates held by Dayton manufacturing facility.