Crude oil
Low sulphur does not mean easy crude.
West African export grades taken on an offtake basis and placed with refiners — priced against Dated Brent, and specified on the parameters that decide what your vacuum column will tolerate rather than the two everybody quotes.
The desk
"Sweet" is a statement about sulphur. It is not a promise about your hot circuits.
Crude is discussed on two axes — light or heavy, sweet or sour — and cargoes are bought and sold on them daily. They are the right first two questions. They are not the question that most often turns a good-looking cargo into an expensive one.
That question is acidity. A crude below 0.5 mg KOH/g total acid number is conventionally treated as non-corrosive; above it, the crude is high-acid and the naphthenic acids in it attack carbon steel in a specific temperature window — beginning around 180–220 °C, most aggressive between 280 °C and 385 °C, and falling away above 400 °C as the acids decompose. That window sits squarely inside the vacuum column and its side-cut piping.
So a barrel can be low in sulphur and still be the harder barrel to run. A refiner with molybdenum-bearing stainless in the hot circuits takes it comfortably and pays for the low sulphur. A refiner without has to blend it down, discount it, or decline it. Nothing on a bill of lading tells you which of those you are talking to, which is why our first question on a crude enquiry is about your metallurgy and not about API.
How we work
We work as offtakers, not as intermediaries looking for a cargo.
Worth stating early, because it changes what we can commit to and what we cannot. The crude market is full of people offering barrels they have no relationship to. We are on the other side of that distinction.
Term commitments to lift
We contract to take defined volumes over a period and place them with refiners, rather than working cargo by cargo on whatever is loose that week.
A known crude, repeatedly
Which is what a refinery actually wants. The same assay across liftings is worth more to a scheduler than a marginally better differential on an unfamiliar barrel.
The origin work is already done
Chain of title, load-port documentation and vessel history sit with the relationship, not assembled after an enquiry. See origin and sanctions.
The assay
Ten lines, each of which decides something.
A crude certificate is short and every line on it changes a refinery decision. These are the ones we report per cargo, the method behind each, and what it actually governs.
| Parameter | Method | What it decides |
|---|---|---|
| Density at 15 °C / API gravity | ASTM D4052 or D1298; D1250 for volume correction | Yield structure and freight economics. The headline number, and the least informative one on its own. |
| Total sulphur | ASTM D4294 (X-ray fluorescence) | Hydrotreating load, finished-product sulphur, and most of the price differential. |
| Total acid number | ASTM D664 (potentiometric titration) | Naphthenic acid corrosion, and therefore which refineries can run the crude neat. See below — the parameter this page is built around. |
| Pour point | ASTM D5853 | Whether the cargo moves without heating, and what happens in a cold discharge port. A blank here is not a minor omission. |
| Water by distillation | ASTM D4006 | What you are paying freight on, and the basis of the BS&W deduction. |
| Water and sediment | ASTM D4007 (centrifuge) | Reported alongside the above; the two together are the outturn argument. |
| Hydrogen sulphide and mercaptans | UOP 136 | Vapour-space safety at loading and discharge, and tank and jetty exposure limits. A safety line before it is a quality line. |
| Copper strip corrosion | ASTM D130 | General corrosivity classification of the cargo as presented. |
| Salt content, nickel and vanadium | Instrumental, named per cargo | Desalter load, and catalyst poisoning downstream in conversion units. |
| True boiling point distillation | Full assay, where available | The actual yield model. A one-page certificate is not an assay, and we say which one we are giving you. |
Acidity
Where naphthenic acid actually attacks.
The reason a high-acid crude is a metallurgy question rather than a chemistry question, set out plainly — because it is the single most useful thing a crude desk can put in front of a buyer who has not run the grade before.
| Temperature | What happens to carbon steel |
|---|---|
| Ambient to about 180 °C | Essentially nothing. Naphthenic acids are not a handling or storage hazard, which is why the problem never appears at the jetty. |
| 180–220 °C | Attack begins. |
| 280–385 °C | Maximum severity. Localised, pitting-like loss rather than general thinning — which is what makes it dangerous, because it concentrates. |
| Above about 400 °C | Falls away as the acids thermally decompose. |
That window puts the exposure in vacuum distillation above all — bubble caps, valve trays and side-cut piping — rather than in the crude tank or the desalter. Carbon steel suffers; 300-series stainless resists, and the molybdenum-bearing grades, 316 and 317, are what refineries running high-acid crude specify in the hot circuits.
The commercial consequence is that acidity segments the buyer pool. A high-acid crude is not universally discounted; it is heavily discounted to refiners who cannot run it and only modestly discounted to those who can. Knowing which side of that line a buyer sits on is most of the work, and it is a question we ask at enquiry rather than discovering through a rejected cargo.
Pricing
A differential is only as good as the quotation behind it.
Crude cargoes price at a differential to a benchmark rather than at a flat number, so the benchmark, the quotation period and the basis are the contract. Agreeing a differential without agreeing those three is agreeing very little.
| Element | What it is | What to fix in the contract |
|---|---|---|
| The benchmark | Dated Brent is the reference for Atlantic Basin crude. Its basket is now six grades — Brent Ninian Blend, Forties, Oseberg, Ekofisk, Troll and WTI Midland, added in 2023 as the first grade from outside the North Sea and the largest single addition of liquidity in the benchmark's history. Assessed daily at 16:30 London. | Name the assessment and the publisher, not just "Brent". Brent futures, Dated Brent and a forward month are three different prices. |
| The basis | North Sea grades are assessed principally FOB, with CIF Rotterdam offers netted back to an FOB-equivalent using a freight adjustment factor. | Whether your differential is against the FOB assessment, and who carries the freight assumption if it is not. |
| The quotation period | Typically an average of the assessment over a window set around the bill of lading date. | How many days, on which side of the B/L date, and what happens when the window crosses a month or a holiday. This moves more money than the differential does. |
| The differential | The premium or discount to the benchmark reflecting grade quality, freight and the state of the market. | Whether it is fixed for the term or reset per lifting, and against which published differential if it floats. |
| Official selling prices | Producers of many export grades publish monthly OSP differentials that set the level for term liftings. | Whether your price follows the producer's OSP or is independently negotiated — and if it follows, what happens if the OSP is published late. |
Origin & sanctions
On crude, a compliance failure is not a commercial problem.
Every product on our book is screened. Crude is the one where the consequence of getting it wrong is criminal rather than contractual, where the documentation is most often forged, and where the pressure to look away is highest because the numbers are large. So this is the section we lead with in a first meeting, not the one we keep for the annexe.
| What we screen | What we require |
|---|---|
| Origin and chain of title | Documented origin from the load port forward, with a full chain of title. Where a cargo has changed hands, we want each step, not a summary. An attestation of origin that cannot be traced to a producing field is not an attestation. |
| The vessel | Ownership, flag, management, class, insurance and age; and whether the vessel or any party to it appears on a designated-vessel list. Designation regimes now reach beyond the carrying vessel itself — providing bunkering or tug services to a designated vessel, or conducting a ship-to-ship transfer with one, can bring a vessel into scope. A clean hull is not a clean fixture. |
| AIS continuity | The voyage track, and an explanation for any gap. Transponder gaps in the wrong waters at the wrong time are the single most common marker on a cargo we decline. Occasionally there is an innocent explanation; we ask for it rather than assuming either way. |
| Ship-to-ship transfers | Whether the cargo has been transferred at sea, where, from what, and why. STS is a legitimate operation with legitimate uses. It is also the mechanism by which origin is laundered, so it triggers documentation rather than a raised eyebrow. |
| Price cap regimes | Where a cap applies, the attestation model and the level in force at the date of the fixture. The level is not static — it has been set by formula against a rolling multi-week average of market price, and the adjustment mechanism has itself been suspended and resumed. We check the position on the day rather than quoting from memory, and we do not publish a figure here that would be stale by the time you read it. |
| Counterparty | Ownership and control to ultimate beneficial owner, against the applicable lists, per consignment rather than once at onboarding. |
Operations
Where the money actually leaks.
Crude margins are thin enough that operational detail is not administration. Quantity disputes and demurrage routinely exceed the differential that was negotiated so carefully.
| Item | Position |
|---|---|
| Vessels | VLCC, Suezmax and Aframax according to parcel size and discharge port restriction. Offshore loading at a single point mooring is normal for many export grades and brings its own weather-related delay exposure. |
| Quantity | Bill of lading figure, ship's figures and shore figures, with a vessel experience factor applied where one exists. Which figure governs outturn is a contract term, not a convention — and it is where most disputes originate. |
| OBQ and ROB | On-board quantity before loading and remaining on board after discharge, both measured and recorded. A cargo is not fully discharged because the pumps stopped. |
| Laytime and demurrage | Notice of readiness, statement of facts, and the laytime clock agreed in the contract rather than argued afterwards. Weather working exclusions matter disproportionately at offshore terminals. |
| Inspection | Independent at load and at discharge, instructed jointly, with sealed retained samples held at both ends. |
| Documents | Bill of lading, certificate of quality, certificate of quantity, certificate of origin, ullage report, notice of readiness, statement of facts, time sheet, and any letters of protest — issued and answered rather than filed. |
Scope
What we are, stated so it cannot be misread.
- We are offtakers
- We contract to lift defined volumes and place them with refiners. That is the business.
- We are not producers
- No equity in production, no reserves, no operatorship. Anyone describing us otherwise is describing us wrongly.
- We do not refine and we do not warrant your yields
- We supply an assay and, where available, a full distillation. What your configuration makes of it is yours to model.
- We do not own vessels
- Chartered tonnage, vetted per fixture. Vetting is a service we perform on our own account and yours; it is not a warranty of the vessel.
- We will not improve an origin
- There is no version of this business in which we help a barrel acquire a better history than it has. Where origin cannot be cleared, we decline, and we do not refer the cargo onward to someone less careful.
How to specify
Six lines and we can have a real conversation.
Crude enquiries usually arrive as a volume and a delivery month. These six make the difference between an indication and an offer.
Your configuration and metallurgy
Hydroskimming, cracking or coking; and your acid tolerance in the hot circuits. This decides which grades are even worth discussing.
API and sulphur window
A range rather than a point, and which of the two binds if they conflict.
Volume and programme
Cargo size, how many liftings, over what period. A term programme and a single cargo are different products.
Pricing basis and quotation period
Benchmark, days, and which side of the bill of lading date. Say it now and it is a term; say it later and it is a negotiation.
Discharge port and vessel limits
Draft, LOA, manifold height, lightering requirement, and any terminal vetting standard the vessel must clear.
Your compliance requirements
Your own screening standard and documentation set. Tell us at enquiry and we will meet it or say we cannot — either answer is faster than finding out at fixture.
Quality
Independent at both ends, with the samples kept.
Inspection by an independent agency appointed for the cargo — SGS, Bureau Veritas or Intertek — instructed jointly, at load port and at discharge, with sampling under supervision and sealed retains held at both ends.
On crude the sampling protocol carries more weight than on almost anything else we handle, because the cargo is heterogeneous, the volumes are large, and a fraction of a percent on water content is a real number. The quality determination point and the quantity determination point are named in the contract, separately, before the vessel is nominated.
- Certificate of quality
- The parameters and methods in the assay table above, each with its designation stated rather than left as "ASTM".
- Full assay where it exists
- True boiling point distillation and cut properties. Where we have it we release it to identified counterparties through the Technical Library; where we do not, we say so rather than presenting a one-page certificate as an assay.
- Missing determinations
- Chased or independently run before offer. A blank line is not treated as an acceptable result.
- Retained samples
- Sealed retains at load and discharge, so a later dispute is settled on the oil.
- Documentation per cargo
- The operational set listed under operations, plus origin documentation and the vessel screening record.
Straight answer
What we will tell you before you ask.
- That we will not move a barrel we cannot document
- Not for a better differential, not for a good relationship, not because the paperwork is promised to follow. This is the one place on our book where we would rather lose the counterparty than the argument.
- That sweet is not the same as easy
- A low-sulphur, high-acid crude is a genuinely good barrel for the right refinery and a genuinely expensive one for the wrong refinery. We will tell you which you are before you buy it, and we would rather place a cargo correctly than quickly.
- That a one-page certificate is not an assay
- And that a certificate with a blank parameter is a certificate with a hole in it. We chase the missing determination rather than forwarding the gap.
- That the quotation period matters more than the differential
- Buyers negotiate cents on the differential and accept the pricing window as drafted. It is usually the wrong way round.
- That we are offtakers and not producers
- We will not let a proposal, a mandate letter or an introduction imply otherwise, and we would treat anyone presenting us as a producer as having misunderstood the relationship.
- Where an origin cannot be cleared
- We decline, we say why, and we do not pass the cargo to someone with a lower threshold — see Compliance.
Enquiries
Every enquiry is answered by the desk that handles it.
Send the product, quantity, delivery basis, destination and timing. We revert with availability, an indication and the documentation that accompanies it. Specifications are released once we know who we are speaking with.