Operators and EPC teams rarely buy “insulated tubing” as a catalogue impulse. They arrive with a thermal problem: steam or hot fluid loses too much heat before it reaches the pay zone; a producing annulus overheats; paraffin or viscosity risk climbs when the fluid cools; permafrost or sensitive casing cement cannot tolerate uncontrolled heat transfer. Vacuum insulated tubing (VIT) is one engineered answer—a dual-wall, vacuum-annulus string—but it is not a substitute for a full OCTG design, and it is not the same decision as dosing a pour-point depressant.
This article walks the buyer path CNPS uses with project teams: operating condition → insulation need → VIT or VIC route → published size/grade/connection options → evidence and RFQ questions. Spec tables and process steps below are attributed to live CNPS product pages fetched for this draft; treat them as published starting points, not project guarantees. Final string design remains with the responsible well-design authority.
Who this page is for
- Operators evaluating steam injection, hot produced fluids, or heat-sensitive wellbores.
- EPC / completion engineers comparing dual-wall vacuum tubulars with conventional tubing plus surface or chemical flow-assurance measures.
- Procurement engineers packaging an RFQ that must capture insulation grade language, OD pairs, steel grade, connection family, and inspection documents—not only “VIT” as a label.
Start with the thermal service question (not the SKU)
Before you open a product page, write down four condition fields. If any field is blank, the quote will guess—and guesses create the wrong OD pair or the wrong evidence pack.
| Condition field | What to capture | Why it matters for VIT |
|---|---|---|
| Heat source / heat sink | Steam injection, hot oil, gas lift heat, geothermal-adjacent service, cold ambient / permafrost, cement temperature limits | Defines whether you need to retain heat in the conduit, protect the annulus/formation, or both |
| Fluid and temperature envelope | Medium, design / operating temperature, pressure class intent | Sets material grade, connection, and insulation discussion; do not invent ratings beyond the offer |
| Geometry and interfaces | Setting depth, hanger / wellhead interface, drift needs, run length, inner vs outer connection preference | Dual-wall strings change OD/ID relationships vs single-wall tubing |
| Evidence expectation | Mill certificates, weld inspection, heat-conductivity records, marking, third-party witness | Insulation performance is process-dependent; documents must match the purchase order |
If the problem is mainly wax crystal / cold-flow behavior in the crude with no wellbore heat-transfer driver, start with the chemical routing map—Which Oilfield Chemical Do You Need? A Problem-to-Product Map—and the PPD family page Pour Point Depressant (PPD) – Low-Temperature Flow Assurance Solution. Chemicals and insulated tubulars can coexist on one field; they answer different failure modes.
What vacuum insulated tubing is (buyer-level cutaway)
On the live CNPS VIT page, vacuum insulated tubing is described as a pre-stressed insulated tubing assembly whose main parts include an inner tube, outer tube, heat insulation material, and coupling. Pre-stress on the inner tube is used to accommodate different thermal elongation between inner and outer tubes as temperature rises—so the string is intended to remain serviceable across the thermal cycle rather than relying on a single-wall pipe with a wrap alone.
Practical buyer takeaways:
- Dual wall is part of the product definition — quote geometry as outer-tube OD × inner-tube ID (or the project’s equivalent convention), not a single OD.
- Vacuum + insulation materials set the heat-conductivity class — CNPS publishes insulation property levels A–E on the VIT/VIC pages (see table below). Ask which level is offered for your line items.
- Connections may be inner, outer, or extreme-line styles — the VIT page states inner and outer tube connections are both available; confirm make-up and running procedures in the RFQ.
- VIT and VIC are related but not identical RFQ objects — tubing vs casing service, loads, and interfaces differ. See Vacuum Insulated Tubing-VIT and Vacuum Insulated Casing-VIC.
Published insulation property levels (from live VIT/VIC pages)
Heat-insulating property level vs heat conductivity coefficient λ as published on CNPS VIT/VIC product pages:
| Level | Published λ range W/(m·°C) (as shown on PDP) |
|---|---|
| A | 0.06 ≤ λ < 0.08 |
| B | 0.04 ≤ λ < 0.06 |
| C | 0.02 ≤ λ < 0.04 |
| D | 0.006 ≤ λ < 0.02 |
| E | 0.002 ≤ λ < 0.006 |
CNPS product copy highlights insulated grades D and E with multi-stage vacuum pumping, automatic welding, and radiographic inspection language. Treat D/E as offered capability classes to confirm on the quote, not as a blanket certificate for every joint until the offer and inspection plan say so.
Decision matrix: when VIT is on the shortlist
| Situation | Lean toward VIT / VIC discussion | Lean elsewhere first |
|---|---|---|
| Steam or hot fluid must arrive at depth with limited heat loss | Yes — dual-wall vacuum string is purpose-built for heat retention in the conduit | Conventional tubing alone may under-deliver on heat conservation |
| Annulus, cement, or permafrost is heat-sensitive | Yes — discuss insulation path and casing/tubing roles (VIC vs VIT) | Surface insulation of flowlines does not solve downhole transfer |
| Primary issue is wax pour point in surface facilities / export crude | Maybe later — string design may help, but start with fluid assays and PPD/viscosity chemistry | Chemical program + operating temperature management |
| Sour service, burst/collapse, or connection qualification dominates | Fold VIT into the broader OCTG load case — do not skip grade/connection design | See general OCTG framing below |
| Corrosion of carbon-steel line pipe in produced water / CO₂–H₂S gathering | Different material path — GRE/FRP line pipe decision | Not solved by vacuum insulation of a steel production string |
For the broader casing/tubing RFQ parent (loads, grade, connection, documents without the thermal specialty), use OCTG Selection and RFQ Guide: Casing & Tubing from Well Design and the hub Specify OCTG around the well—not a catalogue label. For where tubulars sit in the well lifecycle, see Well Construction Lifecycle Map: From Tubulars to Production Equipment.
Published size, grade, and connection options (attribute to PDP)
The following size/grade/connection families are listed on the live VIT and VIC product pages. Confirm availability, exact thread, and performance parameters on the formal offer—do not treat this blog table as a mill tally.
Outer tube OD × inner tube ID (in × in) published examples include: 3½ × 2⅜; 4½ × 2⅞; 4½ × 3½; 5 × 3½; 5½ × 4½; 7 × 5½.
Steel grades named on the PDP: N80, L80, P110.
Connection thread families named on the PDP: inner connection, outer connection, extreme line connection; examples include 3½ USS, 4½ BC, 5 BC, 5½ BC, 7 BC (as listed).
Example performance parameter rows on the VIT page (heat conductivity coefficient with inner-tube inside wall at 350 °C, plus tensile and related columns as published) include model designations such as YG88X50, YG114X62, YG114X76, YG127X62, YG127X76 with published λ bands in the 0.002–0.02 W/(m·°C) range and tensile load minima as shown on that page. Copy those rows into your RFQ only after matching them to the offered line items—do not invent additional models or loads here.
A combined catalogue entry also exists: API 5CT Vacuum Insulated Tubing And Casing. Use it when the buyer’s documentation language is API 5CT–referenced for vacuum insulated tubulars; still state grade, size pair, connection, insulation level, and inspection explicitly—“API” alone does not define the string.
Evidence gate: what to ask for before you award
Insulation performance depends on manufacturing and vacuum integrity, not on a marketing adjective. The live VIT/VIC pages describe production/inspection steps that belong in a buyer checklist:
| Evidence item | Why ask | Buyer note |
|---|---|---|
| Heat conductivity coefficient record per joint (or agreed sampling plan) | PDP states heat conductivity coefficient testing with recorded parameters/curves | Align acceptance criteria with the offered insulation level (D/E or other) |
| Weld inspection (radiographic / X-ray language as offered) | PDP describes X-ray flaw detection on welding seams for weld quality and insulating capability | State standard, coverage, and disposition of indications in the PO |
| Vacuum / getter / storage stability language | PDP discusses getters and outdoor storage without insulation-level reduction | Ask how long and under what storage conditions the claim applies |
| Traceability: heat, joint number, marking | Dual-wall strings still need mill and as-shipped identity | Match marking to tally and running procedure |
| Connection make-up / running procedure | Inner vs outer connection options change field practice | Require written procedure with the offer |
| Third-party witness (if project requires) | Optional; only when contract demands it | Do not imply CNPS always includes third-party inspection unless quoted |
Honesty bound: This article does not claim CE/ISO seals, invented field lifetimes, or market-share figures. Where product marketing mentions reusability or field-share statistics, treat those as vendor statements to verify—not as gate-ready facts for this draft.
RFQ checklist (copy into your enquiry)
Use this list when you email the engineering enquiry form or sales@cnps.com:
- Well / project ID and service description (steam injection, hot production, heat-sensitive annulus, other).
- Temperature and pressure envelope (design and operating), fluid medium, and any sour-service note.
- String role: production/injection tubing (VIT) vs casing (VIC) vs mixed scope.
- Geometry: required outer OD × inner ID (or ID/drift targets), length/tally, setting depth.
- Grade and connection: N80 / L80 / P110 or project grade; inner vs outer vs extreme-line preference; thread form.
- Insulation level target: A–E language or project λ criterion; confirm offered class on quote.
- Inspection and documents: conductivity test plan, radiographic coverage, MTAs/MTCs, marking, packing, destination.
- Witness / third-party requirements, if any.
- Quantity, delivery window, Incoterms, and any running/supervision need.
- Adjacent scope: hanger/wellhead interfaces, cement temperature limits, chemical flow-assurance programs already selected.
FAQ
Is vacuum insulated tubing the same as vacuum insulated casing?
No. Both use dual-wall vacuum insulation concepts on CNPS product pages, but tubing and casing serve different wellbore roles, load cases, and interfaces. Specify VIT vs VIC (or both) explicitly in the RFQ.
Does ordering “API 5CT VIT” finish the technical definition?
No. State size pair, grade, connection, insulation level, inspection, and documents. API-referenced catalogue pages still need project fields filled—same rule as conventional OCTG.
Can chemicals replace VIT for wax problems?
Sometimes surface or production chemistry is the right first lever for pour-point and viscosity problems. When heat loss in the wellbore or annulus is the driver, a thermal string discussion is warranted. Many projects evaluate both; they are not automatic substitutes.
What insulation grade should I put on the PO?
Start from the heat-loss or annulus-temperature requirement your engineer calculates, then map to the published A–E λ bands and the D/E capability language on the CNPS pages. Confirm the offered level, test method, and acceptance criteria on the quote—do not assume every joint is grade E until the offer says so.
Where do I send a VIT enquiry?
Email sales@cnps.com with the RFQ checklist above, or use the engineering enquiry page linked in the CTA.
Enquiry CTA
Send your thermal service description, OD pair targets, grade/connection preference, insulation level language, and document list to sales@cnps.com or open Talk to an Engineer. CNPS can map the condition to the live VIT, VIC, or API 5CT vacuum-insulated catalogue routes already linked above—and flag missing commercial fields before you lock the PO.
