A casing collar locator (CCL) is a downhole magnetic / EM tool that marks casing or tubing collars—and other sharp metal-volume changes—so depth can be correlated during cased-hole or tubing work. It is not a full cased-hole wireline program, not a memory production-logging string, and not a perforating gun. Enquiries stall when they say "send CCL" before anyone writes down the depth job, the conveyance and bus mode, the adjacent tools in the string, and which scopes stay on separate RFQ lines.
This page is a casing collar locator selection guide: when a CCL tool fits depth control, perforation-depth confirmation, or severe casing/tubing metal-volume location—and what to put in the RFQ so offers are comparable. If you are still building the broader multi-tool cased-hole wireline program (cement bond, gamma ray, CCL, memory PL together), start with Cased Hole Wireline Logging Buyer Guide: Cement Bond, CCL, Gamma Ray, and Memory PL RFQ. This article covers the narrower decision: when the CCL tool belongs on the shortlist.
Who this page is for
- Completion, workover and wireline engineers deciding whether a CCL in the string is the right object for depth correlation or perforation-interval confirmation—or whether the real need is a full cased-hole wireline suite, a memory PL string, or the gun program itself.
- EPC and project teams keeping CCL, cased-hole wireline program, memory PL, and perforating guns scopes separate before the RFQ is frozen.
- Procurement engineers writing enquiries that name well/casing identity, depth job, conveyance/bus, connector and environment limits, and acceptance evidence—not a bare product name and a brochure screenshot.
First principles: what a casing collar locator changes
Write down the depth job before choosing any collar tool. Five facts drive most CCL decisions:
- The tool reads metal-volume change, not formation. As published on the live product page, opposing permanent magnets and a coil produce an EMF change when the tool passes a collar or other sharp change in steel volume. That is a depth-correlation signal, not a porosity or fluid-holdup answer.
- Depth control and perforation confirmation are the usual jobs. Published applications include depth control in casing and tubing, location of severe casing or tubing damage, and confirmation of perforation depths / intervals.
- Conveyance and bus mode are project fields. Ultrawire (UW) vs Memory toolbus (Mbus), and slickline memory vs surface readout (with a suitable telemetry controller), change how the signal is stored and who sees it in real time.
- CCL is one tool in a larger program—or a single RFQ line. A multi-tool cased-hole wireline job, a memory PL string, and a perforating run each imply different adjacent scopes and acceptance tests.
- Proof is usable collar picks against the tally, not a label. Without a written depth object, casing/tubing identity, bus/connector notes and who owns the correlation, nobody can say the tool fitted the job.
The live CNPS product page for Casing Collar Locator frames an Ultrawire-compatible CCL with published pressure, temperature, diameter, length and connector limits as published. Whether that tool fits your well depends on the fields below.
Start with the depth object, not the SKU
Lock these fields before freezing bus mode, connector type or environment limits. Blank fields force the quote to guess—often the wrong monitoring object (CCL only vs full cased-hole wireline vs memory PL vs guns), not only the wrong thread.
| Condition field | What to capture | Why it matters for a casing collar locator |
|---|---|---|
| Depth / correlation object | Depth control in casing or tubing; perforation-interval confirmation; severe metal-volume / damage location; or combined (state which) | Defines whether a CCL tool fits vs a full wireline suite, memory PL, or gun-only RFQ |
| Well / string identity | Field/well ID; casing or tubing sizes and weight; known tally or collar schedule; open or restricted ID | Sets diameter and make-up fit; live page frames Ø 38 mm and make-up 470 mm as published—confirm clearance |
| Conveyance | Wireline surface readout, slickline memory, or other (state) | Live page frames slickline memory or surface readout with suitable telemetry controller as published |
| Bus / telemetry | Ultrawire (UW) vs Memory toolbus (Mbus); controller expectations (e.g. XTU / UMT themes on live page) | Wrong bus → wrong interface and string mates |
| Connector / thread | GO banana / end-thread expectation; Sondex-compatible need yes/no | Live page frames 13/16″ 12 UN2A and 4 mm GO banana as published—match to your string |
| Environment | Max pressure and temperature needed; fluid notes | Live page frames 105 MPa and 177°C max as published—confirm against well; do not invent margins |
| Adjacent scopes | Full cased-hole wireline still open; memory PL still open; perforating guns still open | CCL ≠ CBL/GR suite ≠ memory PL ≠ guns |
| Evidence owner | Who correlates collar picks to the tally / perforation plan; FAT/SAT expectations | Label alone does not define acceptance |
When a casing collar locator fits
A CCL tool is worth a serious look when most of the following are true:
- The binding job is depth correlation or perforation-depth confirmation (or locating severe metal-volume change in casing/tubing), not cement-bond quality, fluid holdup, or gun design itself.
- Someone owns the collar-to-tally correlation—wireline or completion personnel will act on the picks, not only archive a file.
- You can state conveyance and bus—surface readout vs slickline memory, UW vs Mbus, and which controller mates are expected.
- Environment and geometry are discussable—max pressure/temperature and ID clearance confirmed against the published limits and the offer.
- Connectors and string mates are ownable—GO / end-thread and any Sondex-compatible expectation written down.
- The CCL RFQ stays separate from full multi-tool cased-hole wireline, memory PL string build, and perforating-gun RFQs when those are still open—or is explicitly nested inside a named program RFQ with its own acceptance line.
- Equipment supply vs crewed wireline service is explicit—tool only, or tool inside a crewed run.
Field check: Multi-tool cased-hole wireline program still open → upstream wireline guide first. Memory PL string build is the object → memory PL path. Gun type / carrier is the object → perforating path. Open-hole vs cased-hole borehole-state still undecided → hub first. Surface mud-logging cabin → out of scope here.
When other paths usually win first
| Situation | Look at first | Why a standalone CCL RFQ is secondary |
|---|---|---|
| Multi-tool cased-hole wireline (CBL + GR + CCL + memory PL) still open | Cased-hole wireline program guide (linked above as upstream) | Program RFQ ≠ single-tool CCL line |
| Memory production-logging string is the object | Memory Production Logging Buyer Guide: String Build, Memory Budget, and RFQ Fields | Memory PL budget and sensors ≠ CCL-only depth pick |
| Perforating gun type / carrier is the object | Perforating Guns Buyer Guide: Gun Type, Carrier Pipe Tolerances, and RFQ Fields | Guns create the interval; CCL confirms depths—keep scopes separate |
| Open-hole vs cased-hole borehole state still undecided | Open-Hole vs Cased-Hole Logging: Differences, Tools & When to Use Each | Hub first; CCL after cased-hole path is chosen |
| No depth object, no tally owner, no bus/connector written down | Write those fields before any SKU | Label alone does not define the object |
Casing collar locator vs cased-hole wireline vs memory PL vs perforating (keep the scopes separate)
The labels overlap in conversation; the objects do not. A casing collar locator is the depth-correlation tool decision only.
| Scope | Typical decision | Acceptance evidence you would expect |
|---|---|---|
| Casing collar locator (this page) | When a CCL tool fits depth / perforation confirmation / severe metal-volume location | Collar picks usable vs tally; bus/connector as offered; environment within offered limits |
| Cased-hole wireline program | When a multi-tool CH wireline suite fits | Tool list, interfaces, and program-level FAT/SAT—not only one CCL curve |
| Memory production logging | When a memory PL string fits production surveillance | Memory budget, sensor set, download/QC—not only collar marks |
| Perforating guns | When gun type and carrier fit the interval plan | Gun/carrier tolerances and shot plan; CCL may confirm depths on a separate line |
| Open-hole vs cased-hole hub | When borehole-state routing is still open | Program path chosen before tool SKUs |
Writing one PO line that mixes "CCL + CBL + memory PL + guns" without separate data objectives and acceptance tests creates the wrong evidence pack for each scope. Adjacent tools stay on separate RFQs (or clearly nested lines) if needed—do not explode SKUs here.
What the live product page already states (honesty bounds)
As published on the live CNPS product page Casing Collar Locator (post 747, checked 2026-11-02):
- Toolstring framing: Operates as part of an Ultrawire toolstring; derives power and control from a suitable system controller (e.g. XTU) as published.
- Operating principle: Fields of two opposing permanent magnets pass through a coil between them; movement of flux lines altered by steel-volume change produces an EMF across the coil; axial magnet arrangement minimizes unwanted sideways-motion signal as published.
- Applications: Depth Control in Casing and Tubing; Location of Severe Casing or Tubing Damage; Confirmation of perforation depths / intervals as published.
- Interfacing: Simultaneous operation with other CNPS tools; standard CNPS GO or other connections; Sondex compatible and interchangeable as published.
- Options: Ultrawire™ toolbus (UW) or Memory toolbus (Mbus); slickline memory or surface readout mode (with suitable telemetry controller) as published.
- Specification (as published): CCL Telemetry XTU or UMT; Pressure(max) 105 MPa; Temperature(max) 177°C; Voltage(nominal) 18 VDC; Current <16 mA; Length(make-up) 470 mm; Measure Point 165 mm; Diameter 38 mm; Weight 5.1 kg; End Thread (top/bottom) 13/16″ 12 UN2A; GO End connector (top/bottom) 4 mm single banana connector; Material Corrosion Resistance throughout as published.
Honesty bound: Not a certified performance sheet for your well. Pressure, temperature, diameter, length, current and connector figures are cited as published; confirm every figure on the offer and datasheet. No invented DOI, accuracy %, certificate numbers, monogram details or ROI appear here. Unknowns (e.g. project-specific accuracy vs tally, fluid-compat margins beyond the published envelope) stay flagged as confirm-on-offer.
RFQ fields that keep casing collar locator quotes comparable
Copy these into the enquiry so replies stay comparable.
| RFQ field | What to write | Honesty bound |
|---|---|---|
| Depth-object intent | CCL for depth control / perforation confirmation / severe metal-volume location (state primary job) | Do not hide an open full-wireline or gun-only debate |
| Well / string identity | Field/well ID; casing or tubing size/weight; tally available yes/no; ID restrictions | Unknown is better than invented geometry |
| Conveyance | Wireline surface readout, slickline memory, or other | Confirm against published memory / SRO options as published |
| Bus / telemetry | UW or Mbus; controller notes (XTU / UMT themes) | Match offered bus—do not assume |
| Connector / thread | GO banana / 13/16″ 12 UN2A need; Sondex-compatible yes/no | Confirm offered ends as published |
| Environment | Max pressure and temperature required; fluid notes | Compare with published 105 MPa / 177°C as published—confirm on offer |
| Geometry | Required OD clearance; make-up length limits; measure-point notes | Compare with published 38 mm / 470 mm / 165 mm as published |
| Power notes | Nominal voltage / current expectations if relevant to string | Live page frames 18 VDC / <16 mA as published—verify in string design |
| Evidence / FAT-SAT | Collar-pick QC vs tally; packing; destination; spares | No fake certificate numbers or invented DOI |
| Related scopes | Separate RFQs for cased-hole wireline program / memory PL / perforating guns, or "none" | Keep objects separate |
| Project ID + engineer | Who owns depth correlation and acceptance; logistics | Required for comparable replies |
For live catalogue framing and the published Ultrawire / magnet-coil / environment notes, see Casing Collar Locator when you are ready to match an offered configuration.
When the fields above are filled in, send them through Request a quotation so the offer is priced against your depth object, not a generic brochure pack.
FAQ
Is a casing collar locator the same as a full cased-hole wireline program?
No. A casing collar locator is one depth-correlation tool. A cased-hole wireline program may combine cement bond, gamma ray, CCL, memory PL and other sensors under one program RFQ. Keep the program guide and the CCL tool RFQ distinct when both are in scope.
Does a CCL replace perforating guns?
No. Perforating guns create the interval. A CCL is commonly used to confirm perforation depths / intervals against the collar tally. Gun selection and CCL selection stay on separate decision lines.
Can a CCL run in memory mode on slickline?
The live product page frames slickline memory or surface readout options (with a suitable telemetry controller) and UW or Mbus toolbus choices as published. Say which mode you need in the RFQ and confirm on the offer—do not assume every string mate is included.
Are the published 105 MPa and 177°C figures guarantees for every well?
No. They are catalogue max figures as published on the product page. Treat them as selection language to confirm on the datasheet and offer for your well—not a universal project guarantee invented here.
What about older CCL overview pages on this site?
Prefer this selection/RFQ page and the live product page for current enquiry language. Weak older overview siblings are not refreshed here and are not competing targets.
What is the single most useful RFQ field?
A written depth object plus well/string identity, conveyance/bus, and who owns collar-to-tally correlation. Without those, offers cannot be compared and FAT/SAT cannot be judged.
Talk to engineering
If depth correlation or perforation-depth confirmation is the binding job and a casing collar locator is on the shortlist, start here: Talk to an Engineer. For commercial follow-up, email sales@cnps.com once with the same depth-object note, well/string identity, conveyance/bus, connector/environment limits, related-scope list and project ID.
