Depth, pressure, temperature, axial load, buckling, hydraulics and well trajectory.
PRODUCTION & INTERVENTION
Coiled Tubing
Continuous tubing supply for intervention, circulation and selected production applications.
StandardAPI Spec 5ST · Customer intervention or completion specification
Size / supply rangeOutside diameter, wall thickness and total continuous length reviewed together · Reel size and transport limits coordinated with the string
Grades / materialsCarbon and low-alloy coiled-tubing grades · Sour-service and corrosion-resistant material routes subject to qualification
Connections / optionsContinuous string with project-specific end termination · Reel, injector and well-control equipment interfaces reviewed separately
CONTINUOUS WELL-INTERVENTION TUBULAR
A continuous string engineered for repeated deployment.
Coiled tubing is continuously milled steel tubing supplied on a reel for workover, intervention, completion and selected permanent-installation duties. It can be run into and retrieved from a well without making or breaking conventional threaded joints, enabling circulation during many operations.
OAK PIPE coordinates string design inputs, grade, diameter, wall profile, continuous length, weld traceability, inspection, reel configuration and international delivery.
Repeated bending over reel, guide arch and injector changes the usable life of the string.
Final string length, reel core, flange, gross weight and transport limits must be designed together.
SUPPLY OVERVIEW
Typical coiled tubing specifications.
Coiled tubing is an engineered string rather than a simple cut length of pipe. Final supply is confirmed from the complete operational and transport requirement.
| Primary product standard | API Spec 5ST for carbon and low-alloy steel coiled tubing; purchaser requirements may add design, inspection or service criteria |
|---|---|
| API grade families | CT70, CT80, CT90, CT100 and CT110 |
| Typical industry OD envelope | Approximately 1 in to 5 in (25.4–127.0 mm) across established industry offerings; OAK supply availability is confirmed per enquiry |
| Wall configuration | Constant wall or tapered / multi-wall string designed around loads, hydraulics, fatigue and total reel weight |
| Continuous length | Defined by operating depth, string design, manufacturing plan, reel capacity and transport envelope |
| Manufacturing concept | Continuously milled and longitudinally welded tubing formed from strip segments joined under a controlled manufacturing plan |
| String ends | Plain ends or order-specific end preparation for field-installed connectors / bottom-hole assemblies |
| Surface condition | Order-specific external preservation; internal surface and treatment requirements reviewed by application |
| Reel supply | Shipping or operational reel configuration subject to core diameter, flange diameter, width, capacity and handling limits |
| Identification | String / reel identification, heat and strip traceability, length references and order-specific marking |
Published size ranges from established manufacturers are useful market references, but they do not establish OAK availability for every grade–diameter–wall–length combination.
API 5ST GRADES
Strength is balanced against cyclic service.
The API grade designation indicates specified minimum yield strength. Higher strength does not automatically mean longer field life: fatigue, corrosion, wall profile and operational history remain critical.
| Grade | Specified minimum yield | Selection context |
|---|---|---|
| CT70 | 70 ksi / 483 MPa | Lower-strength API grade for suitable work-string, completion or static-installation requirements. |
| CT80 | 80 ksi / 552 MPa | Common API strength level balancing load capacity and cyclic service considerations. |
| CT90 | 90 ksi / 621 MPa | Intermediate API grade for higher design loads where the complete string analysis supports selection. |
| CT100 | 100 ksi / 690 MPa | Higher-strength API grade for demanding depth and pressure envelopes. |
| CT110 | 110 ksi / 758 MPa | Highest grade listed in API 5ST; requires careful fatigue, environment and handling review. |
STRING ENGINEERING
Four inputs shape a practical coiled tubing string.
A technically meaningful quotation needs the working envelope and reel limits, not only OD and total length.
Load
Axial & Pressure EnvelopeString weight, injector force, well pressure, internal pressure and combined loading.
Life
Low-Cycle FatigueBending history, pressure cycles, reel geometry and expected intervention program.
Flow
Hydraulic PerformanceRequired pump rate, pressure loss, fluid type, solids and internal diameter profile.
Reel
Transport EnvelopeCore and flange geometry, reel width, gross weight, lifting and destination restrictions.
APPLICATIONS
One continuous tubular across multiple well operations.
Each use case produces a different combination of loading, pressure, fatigue, corrosion and bottom-hole assembly requirements.
Well Cleanout
Circulation, solids removal and restoration of wellbore access.
Nitrogen Lifting
Gas injection through the string to unload fluids and assist well start-up.
Acidizing & Stimulation
Placement of treatment fluids with material compatibility and pressure reviewed.
Logging & Conveyance
Deployment of tools in deviated or horizontal wells where gravity conveyance is limited.
Coiled Tubing Drilling
Selected drilling operations requiring dedicated string, fatigue and hydraulics design.
Completion / Velocity String
Temporary or permanent installations subject to the appropriate design basis.
STRING CONFIGURATION
Wall profile, length and reel form one deliverable.
A tapered string can place heavier wall where loads are greatest while controlling hydraulics and reel weight. The transition plan, continuous length, field end requirement and reel geometry should be agreed before manufacturing release.
Constant-wall stringsTapered / multi-wall stringsWork stringsCompletion stringsStatic installationsShipping and operational reels
MANUFACTURING & QUALITY
Continuous traceability across the complete string.
The manufacturing and inspection plan addresses incoming strip, strip-end joints, longitudinal weld, dimensions, pressure integrity and final reel release.
01Specification, string and reel review
02Strip identity, chemistry and mechanical properties
03Strip-end joining and continuous forming
04Longitudinal welding and online process control
05NDT, dimensions, mechanical and pressure testing
06Spooling, marking, documentation and final release
Typical available documents
Mill Test Certificate · Strip / heat traceability · Chemical and mechanical results · Weld / NDT records · Dimensional and wall-profile report · Pressure-test record · String tally · Reel drawing and data · Packing list · Third-party inspection records when ordered
COILED TUBING RFQ CHECKLIST
Send the operating envelope and transport limits.
With these inputs, OAK PIPE can evaluate a practical string and reel configuration instead of quoting an isolated pipe size.
Request a Coiled Tubing Quote- 01Outside diameter, target wall profile, grade and total continuous length
- 02Maximum working depth and well trajectory information
- 03Internal / external pressure, axial load and planned pump rate
- 04Temperature, fluid composition, H₂S / CO₂ and corrosion-control plan
- 05Expected jobs, pressure cycles and fatigue-life requirement
- 06Reel limits, gross-weight restriction, lifting, transport route and destination
PRODUCT & PROCESS VIEWS
Product views and manufacturing context.
Representative product, production and inventory views support preliminary identification. Final supply details are confirmed against the quotation.
START A CONVERSATION
Have a specification or product list?
Send it to OAK PIPE for technical and commercial review.