Capillary tubing & pressure transmission
Small-diameter continuous tube form; a fluid-filled line may convey downhole pressure to a surface sensor. Temperature sensing requires a separate qualified sensor or fiber system.
CAPILLARY TUBING & CONTROL LINES
Downhole Control & Injection Lines
Small-diameter continuous tubing for downhole chemical injection, pressure transmission and specified hydraulic-control applications.
StandardApplicable ASTM alloy-tubing specification, selected by material and manufacturing route · Project completion specification and inspection/test plan
Size / supply rangeCommon reference ODs: 1/8, 1/4 and 3/8 in. · OD, wall thickness, minimum bore, continuous length and reel limits confirmed together
Grades / materials316L, 2205 and 2507 stainless-steel options · Alloy 825 and Alloy 625 for selected corrosive environments; other alloys by review
Connections / optionsBare or specified encapsulated line · Single-line or project-defined multi-line arrangement
PRODUCT OVERVIEW
Downhole Control & Injection Lines for project-specific requirements.
This family covers small-diameter continuous alloy tubing selected for a defined downhole function. Capillary tubing describes the tube form; chemical-injection and hydraulic-control lines describe different duties, media and termination requirements. These lines are not the larger coiled tubing used for temporary well-intervention operations.
A chemical-injection line conveys a qualified treatment fluid to a selected depth. A hydraulic-control line transmits pressure to a specified downhole actuator, such as a subsurface safety valve. A fluid-filled pressure-transmission line can convey downhole pressure to a surface sensor; temperature measurement requires a separate qualified sensing arrangement. The end connection, cleanliness, pressure test and material compatibility must be reviewed for each duty.
Selection depends on the well environment, conveyed fluid, outside diameter, wall thickness, continuous length, material and manufacturing route. Lines may be bare or, where specified, encapsulated or combined in a multi-line arrangement. Valves, clamps, feed-throughs, pumps and monitoring equipment shown are system context, not an automatic part of tubing supply. Final scope, pressure rating and acceptance criteria are confirmed for each order.
APPLICATION PATHS
One tubing family, three distinct duties.
The intended function determines the fluid, termination, testing and documentation to specify.
Hydraulic control lines
Transmit hydraulic pressure to a specified downhole actuator. Valve interfaces, pressure retention, control-fluid cleanliness and response requirements are reviewed for the completion design.
Chemical injection lines
Deliver a qualified treatment chemical to a selected downhole point. Chemical compatibility, cleanliness, flow path and the injection termination are defined for the project.
TECHNICAL SCOPE
Supply basis at a glance.
Use this overview to prepare an enquiry. The final size, grade, connection and inspection combination is confirmed against the governing specification.
| Technical field | Available or review basis |
|---|---|
| Standards | Applicable ASTM alloy-tubing specification, selected by material and manufacturing route · Project completion specification and inspection/test plan |
| Size & supply range | Common reference ODs: 1/8, 1/4 and 3/8 in. · OD, wall thickness, minimum bore, continuous length and reel limits confirmed together |
| Grades & materials | 316L, 2205 and 2507 stainless-steel options · Alloy 825 and Alloy 625 for selected corrosive environments; other alloys by review |
| Connections & options | Bare or specified encapsulated line · Single-line or project-defined multi-line arrangement · End preparation, feed-through and downhole interface by approved design |
| Product form | Small-diameter continuous alloy tubing, supplied on a reel to the confirmed order length |
| Pressure rating | Established for the ordered material, size, manufacturing route, temperature and termination; no universal OAK rating is stated |
APPLICATIONS
Where this product is used.
- Targeted downhole injection of qualified treatment chemicals
- Fluid-pressure transmission to a surface monitoring system
- Related hydraulic-control and fiber-optic line configurations when specified
SERVICE & SELECTION
Conditions considered during selection.
- H₂S, CO₂, chlorides, temperature and produced-fluid chemistry
- Injected-chemical compatibility and cleanliness
- Installation bending, clamping and abrasion risks
- System pressure and termination integrity
MANUFACTURING
Controlled production route.
Key operations are coordinated against the product specification and order requirements.
01Confirm seamless or welded-and-drawn route for the selected alloy and length
02Control material identity, dimensions and continuous-length records
03Specify cleaning or electropolishing only where required
04Load and protect the completed line on an agreed reel
INSPECTION & TESTING
Verification before release.
- Material and dimensional checks against the order
- Eddy-current or other agreed NDT by manufacturing route
- Hydrostatic or pneumatic pressure/leak test to the approved procedure
- End, cleanliness and reel inspection as specified
QUALITY DOCUMENTS
Evidence supplied with the order.
- Material certificate and traceability
- Dimensional and NDT records
- Pressure/leak-test report
- Reel length and identification record
PACKING & DELIVERY
Prepared for the destination and handling plan.
Marking, protection and shipment details are confirmed during order review.
Protected and sealed ends
Reel sized for bending and transport limits
Handling and shipment protection agreed for the destination
RFQ CHECKLIST
Information needed for a practical quotation.
Share the available technical and commercial requirements. Missing details can be reviewed with our team.
Request a Quote- 01Function: chemical injection, pressure transmission or other control-line use
- 02OD, wall thickness, minimum bore, continuous length and quantity
- 03Alloy, seamless/welded route and well-fluid/chemical environment
- 04Working and design pressure, temperature and termination details
- 05Encapsulation, reel, inspection, cleanliness and document requirements
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.