A vacuum insulated casing (VIC) string is not “insulated tubing with a different name,” and it is not a drop-in substitute for a pour-point chemical program. It is a casing-role dual-wall vacuum tubular: an outer tube, inner tube, insulation / vacuum annulus, and coupling family intended to manage wellbore heat transfer when the casing path—not only the production/injection tubing—is part of the thermal design. Operators and EPC teams lose time asking for “VIT” before they lock heat source, annulus/cement temperature limits, string role (tubing vs casing), OD pair, grade/connection, and insulation-level language.
This page is a selection and RFQ framing guide for VIC. It does not reprint every cell of the live catalogue tables as universal guarantees, and it does not rewrite the published vacuum insulated tubing (VIT) selection post. Use the money page to match an offered configuration; use this article when the open question is still whether vacuum insulated casing fits.
Who this page is for
- Completion / well-construction engineers deciding whether a dual-wall vacuum casing path fits steam, hot-fluid, or heat-sensitive annulus / cement / permafrost duty.
- EPC / project teams keeping VIC casing, VIT tubing, and general OCTG scopes separate before the RFQ hardens.
- Procurement engineers writing RFQs that name operating conditions, string role, and evidence, not only “send VIC” as a label.
Start with the operating condition (not the SKU)
Lock these fields before freezing a catalogue size/grade row. Blank fields force the quote to guess—often the wrong string role (tubing vs casing), not only the wrong OD pair.
| Condition field | What to capture | Why it matters for vacuum insulated casing |
|---|---|---|
| Thermal driver | Steam injection, hot produced / injected fluid, heat-sensitive annulus, cement temperature limits, permafrost / cold ambient notes | Defines whether you need to retain heat, protect the annulus/formation, or both—and whether the casing path is in scope |
| String-role hypothesis | Casing (VIC) vs tubing (VIT) vs mixed / staged scope | VIC ≠ VIT — different wellbore role, interfaces, and RFQ objects |
| Fluid and envelope | Medium, design / operating temperature intent, pressure class intent, sour-service note | Sets grade, connection, and insulation discussion; do not invent ratings beyond the offer |
| Geometry and interfaces | Setting depth / interval, hanger / wellhead / shoe interfaces, drift needs, outer OD × inner ID targets, run length | Dual-wall strings change OD/ID relationships vs single-wall casing |
| Insulation intent | Project λ / heat-loss criterion or published A–E level language you can share | Live VIC page publishes insulation property levels as published—match on the offer |
| Evidence already held | Prior temperature surveys, cement / annulus limits, workover history, thermal-model notes | Separates “wrong insulation class” from “wrong string role or wrong thermal method” |
| Adjacent paths | Chemical flow-assurance already selected; conventional OCTG load case still open | Thermal casing ≠ chemical-only fix; VIC still sits inside OCTG design |
If the open question is still tubing-role dual-wall vacuum insulation (production/injection string), use Vacuum Insulated Tubing (VIT): When Thermal Service Needs a Dual-Wall String. If the problem is mainly wax / cold-flow chemistry with no wellbore heat-transfer driver for the casing path, start with Flow Assurance in Oilfields: When Chemicals Fit vs When Equipment Paths Fit. This article sits on a different object: when vacuum insulated casing is the shortlist item.
When vacuum insulated casing fits
Lean toward a VIC (dual-wall vacuum casing) discussion when most of the following are true:
- Casing is the intentional thermal string role — you need insulation on a casing interval or casing-role tubular, not only on the production/injection tubing.
- A wellbore heat-transfer driver is real — steam or hot fluid, annulus/cement temperature limits, permafrost or heat-sensitive formations, or a documented need to limit heat leaving (or entering) across the casing path.
- Dual-wall vacuum construction is intentional — you are evaluating a pre-stressed insulated dual-wall assembly (inner tube + outer tube + insulation / vacuum + coupling) as published on the VIC product page, not a single-wall casing with a wrap alone.
- You can state geometry as an OD pair (or project equivalent) — outer-tube OD × inner-tube ID (or drift/ID targets), not a single conventional casing OD label alone.
- Insulation-level language is ownable on the RFQ — published A–E λ bands and D/E capability framing on the live page are selection language to confirm on the offer, not a free project guarantee.
- VIC scope is separate from VIT and general OCTG RFQs — do not collapse “send insulated tubulars” into one PO line that mixes tubing acceptance, casing acceptance, and conventional OCTG documents without separate criteria.
Field check: If the team has already locked a tubing-only VIT path and the casing remains conventional by design, do not force a VIC RFQ as a silent synonym for VIT. If burst/collapse, sour service, or connection qualification still dominate and no thermal casing driver exists, fold insulation into the broader OCTG load case—or stay on conventional casing until the thermal need is written down.
When VIT, chemicals, or conventional OCTG usually win first
| Situation | Lean other path first | Why vacuum insulated casing is secondary |
|---|---|---|
| Thermal string role is tubing (production/injection) | VIT selection sister | Tubing ≠ casing — different RFQ object |
| Primary issue is wax pour point / cold-flow in facilities with no casing heat-transfer driver | Flow-assurance chemicals vs equipment routing | Chemical path ≠ dual-wall casing |
| Need is general casing grade / connection / documents without thermal specialty | OCTG selection RFQ parent | VIC is a thermal subset, not a full OCTG encyclopedia |
| Corrosion of gathering line pipe (CO₂/H₂S/produced water) | GRE/FRP line-pipe path (separate cluster) | Not solved by vacuum-insulating a steel casing string |
| GRE / fiberglass casing for corrosion or weight (different material path) | Existing composite-casing content / GRE casing PDP | Steel dual-wall vacuum ≠ GRE casing |
| Only a combined “API 5CT vacuum insulated” catalogue label is known | Still split tubing vs casing roles + fill project fields | Label alone does not define the 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 once.
VIC vs VIT vs general OCTG (keep the scopes separate)
Vacuum insulated casing is the casing-role dual-wall vacuum tubular decision. It is not vacuum insulated tubing and not a full conventional OCTG RFQ by itself.
| Scope | Typical decision | Sister / money page |
|---|---|---|
| Vacuum insulated casing (this page + PDP) | When VIC fits; OD pair; grade/connection; insulation level; casing-role evidence | This article + live VIC PDP (linked once below) |
| Vacuum insulated tubing (VIT) | When tubing-role dual-wall vacuum fits | VIT selection sister (linked above) |
| General OCTG casing/tubing RFQ | Loads, grade, connection, documents without thermal specialty | OCTG selection RFQ parent (linked above) |
| Chemicals vs equipment flow assurance | When PPD/viscosity chemistry vs equipment paths fit | Flow-assurance sister (linked above) |
Field check: Writing one PO line that mixes “VIT + VIC + API 5CT vacuum insulated” without separate string-role, geometry, insulation, and acceptance criteria creates the wrong evidence pack for each scope.
What the live product page already frames (honesty bounds)
As published on the live CNPS product page for Vacuum Insulated Casing-VIC:
- Product-family framing: vacuum insulated casing; copy also discusses vacuum insulated tubing & casing together and describes a pre-stressed insulated tubing assembly structure (inner tube, outer tube, heat insulation material, coupling) used to accommodate different thermal elongation between inner and outer tubes as published. Treat shared structural language as published starting points—still specify casing role and project interfaces on the RFQ.
- Key-feature language as published: insulated grades D and E; multi-stage vacuum pump / automatic welding / online radiographic themes; outdoor-storage framing that insulation level does not reduce; inner-tube and outer-tube connections both available.
- Reusability / retention-of-insulation language after multiple uses as published — treat as vendor selection language to verify, not a project lifetime guarantee in this blog.
- Insulation property levels A–E with published heat-conductivity coefficient (λ) bands as published on the page (same A–E table framing also used on related VIT/VIC catalogue copy):
| 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 |
- Size / grade / connection families listed on the VIC page (under a “VIT Specification” heading as published on that page—confirm casing-role applicability on the offer): outer tube OD × inner tube ID examples include 3½ × 2⅜; 4½ × 2⅞; 4½ × 3½; 5 × 3½; 5½ × 4½; 7 × 5½. Steel grades named: N80, L80, P110. Connection families named: inner connection, outer connection, extreme line connection; thread examples include 3½ USS, 4½ BC, 5 BC, 5½ BC, 7 BC as listed.
- Example performance-parameter model rows (YG88X40, YG88X50, YG114X62, YG114X76, YG127X62, YG127X76 and related columns) appear as published with heat-conductivity bands in the 0.002–0.02 W/(m·°C) range and tensile / related figures as shown on that page. This blog does not reprint every cell as a universal guarantee—match models and acceptance on the formal offer.
- Production/inspection language as published: X-ray / radiographic flaw detection on welding seams; heat-conductivity coefficient testing with recorded parameters/curves (page states 100% test language for heat conductivity coefficient).
Honesty bound: Do not treat a blog selection page as a certified rating sheet. Project λ, tensile loads, reusability, storage life, and certificate numbers belong in engineering calculation and the formal offer—as offered / as published. Do not invent API/ISO/CE badge claims. Do not invent casing-specific burst/collapse or cement-bond guarantees that the VIC page does not publish.
RFQ fields that keep VIC quotes comparable
Copy these into the enquiry so VIC quotes stay comparable and do not collapse into a vague “send insulated casing” ask—or a silent swap for VIT tubing.
| RFQ field | What to write | Honesty bound |
|---|---|---|
| String-role intent | Vacuum insulated casing (VIC) intentional (or state if VIT vs VIC still open) | Do not hide an open tubing/casing debate |
| Thermal service | Steam / hot fluid / heat-sensitive annulus / cement or permafrost notes | Wrong driver → wrong RFQ |
| Well / interval identity | Field/well ID, setting depth / interval, hanger / shoe / wellhead interface notes | Unknown is better than invented geometry |
| Geometry | Outer OD × inner ID (or ID/drift targets); tally / length class | Dual-wall — confirm pair on offer |
| Grade / connection | N80 / L80 / P110 or project grade; inner vs outer vs extreme-line preference; thread form | Live page lists families as published—match on offer |
| Insulation level | A–E language or project λ criterion; D/E if that is the intent | Confirm offered class + test method—no assumed grade E |
| Envelope | Temperature / pressure intent; medium; sour-service note | No invented ratings in the blog |
| Evidence docs | Conductivity test plan, radiographic coverage, MTAs/MTCs, marking, packing, destination | No fake certificate numbers |
| Related scopes | Separate RFQs for VIT tubing / conventional OCTG / chemicals if any (or “none”) | Keep objects separate |
| Project ID + engineer | Who owns duty and acceptance | Required for comparable replies |
For live catalogue framing and the published size/insulation/inspection notes, use Vacuum Insulated Casing-VIC once you are ready to match an offered configuration.
FAQ
Is vacuum insulated casing the same as vacuum insulated tubing?
No. Both use dual-wall vacuum insulation concepts on CNPS product pages, but tubing and casing serve different wellbore roles, interfaces, and RFQ objects. Specify VIC vs VIT (or both) explicitly. Use the VIT selection sister when the tubing path is open; use this page when the casing path is open.
Does the live VIC page only talk about “casing”?
The live product title/H1 is Vacuum Insulated Casing-VIC. The body also shares structural tables and “VIT Specification” / tubing-assembly language with related vacuum-insulated catalogue copy as published. For procurement, still state casing role, geometry, insulation level, and acceptance on the RFQ—do not assume a shared table cell is a casing-specific project guarantee until the offer says so.
Can chemicals replace VIC for wax problems?
Sometimes surface or production chemistry is the right first lever for pour-point and viscosity problems. When heat transfer across a casing interval or heat-sensitive annulus/cement is the driver, a VIC discussion is warranted. Many projects evaluate chemicals and thermal tubulars together; they are not automatic substitutes. See the flow-assurance sister linked above once.
What insulation grade should I put on the PO?
Start from the heat-loss or annulus/cement temperature requirement your engineer calculates, then map to the published A–E λ bands and the D/E capability language on the CNPS VIC page. 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 see live product framing?
On the live product page titled Vacuum Insulated Casing-VIC (linked once above)—catalogue scope and published insulation/size/inspection notes there; fit and RFQ framing here.
Talk to engineering
If thermal wellbore service is intentional and vacuum insulated casing is on the shortlist, start here: Talk to an Engineer. For commercial follow-up, contact sales@cnps.com once with the same string-role note, thermal driver, geometry (OD pair), grade/connection, insulation-level language, evidence-scope note, and project ID.
