Refined fuels are commodities with a spec sheet; crude is an agricultural product with a geology. Every field's barrel is its own blend of molecules, worth more to one refinery than another, priced off benchmarks it never quite matches, and moved through a custody chain built to survive arguments. This page is the buyer's plain-language orientation: what the quality numbers mean, how pricing really works, what the paper trail looks like, and the diligence that separates trade from theater.
Reading a barrel: gravity, sulfur, and the assay
Two numbers open every conversation. API gravity is density upside down, higher is lighter: light crudes above roughly 31 degrees, heavies below about 22, condensate lighter than all of it. Sulfur splits the world at about half a percent: sweet below, sour above. Light and sweet means more gasoline and diesel per barrel with less refinery effort, so West Texas Intermediate at around 40 API and 0.3 percent sulfur anchors one end of the scale while heavy sour grades anchor the other, selling at discounts because only refineries built with coking and desulfurization capacity can digest them profitably. The full story lives in the assay, the crude's laboratory resume: distillation-cut yields, acid number, metals, viscosity, everything a refiner needs to model the barrel through the plant. Serious sellers produce current assays; serious buyers read them before price ever comes up.
How the barrel gets priced
Crude prices as a relationship, not a number: benchmark plus or minus differential, averaged over agreed dates. The benchmarks are the famous tickers, WTI at Cushing for US barrels, Brent for the waterborne Atlantic world, with regional markers and formula prices covering grades the majors don't, heavy Latin American crudes among them. The differential is where the deal actually lives: it prices the quality gap against the benchmark barrel and the freight gap to the refinery that wants it, and it moves with refinery appetite, freight markets, and politics while the benchmark grabs the headlines. A cargo might trade as benchmark minus a few dollars, pricing over five days around bill-of-lading date, and both parties watch the calendar as closely as the screen, because which days average is worth real money on a large cargo.
Terms and the moment of truth
Delivery terms set who owns which risks. FOB, free on board, passes title and risk at the load port flange: the buyer charters the ship, carries the voyage, and owns what happens at sea. CIF and delivered terms keep freight and insurance on the seller into the discharge port. Either way, the cargo's facts get established at custody transfer by an independent inspection company: quantity by fiscal meters or verified tank gauges, quality by samples drawn, tested, and retained against later dispute, everything certified in documents that the invoice and the bank will treat as the truth. Payment in international crude runs on bank instruments, letters of credit above all, documents against payment through banks both sides trust, because cargo values run into the tens of millions and nobody sane ships on a promise. The marine mechanics, laycans, laytime, demurrage, have their own vocabulary, and the one-sentence version is: the schedule is contractual, and idle ship time is billed by the day at rates that concentrate the mind.
Diligence: the part that isn't optional
The crude market has a documented-deal culture for a reason, and it also has a famous population of fakes: brokers with no barrels, letters that photograph well and verify never, procedures that invert how real trade works. The screen is unglamorous: verify the seller's title or allocation at the source, verify the assay and the inspector, verify sanctions status of every party, vessel, and origin against current lists, and let banks and inspection companies do the jobs the fakes always want skipped. A counterparty who resists independent inspection, bank instruments, or origin documentation has answered the diligence question already. Real cargoes survive scrutiny; that's what makes them real.
Common questions
How big is a cargo?
Ocean lots run from Handysize and MR parcels in the low hundreds of thousands of barrels through Aframax and Suezmax to VLCCs around two million barrels. Inland, the units are pipeline batches, barges, and 500-barrel-class truck loads, and the arithmetic bridge is that a metric ton is roughly 7.3 barrels, varying with gravity.
Why do heavy crudes trade at all if they're discounted?
Because refineries built for them make excellent margins on the discount: coking capacity turns cheap heavy barrels into the same gasoline and diesel as anyone else's. The discount is a processing fee, not a defect notice, and matching grade to refinery is most of what crude marketing is.
What does a marketer like Vexon actually add?
Matching barrels to buyers, structuring terms both sides' banks will accept, running the inspection and documentation chain, and coordinating the logistics from tank to tank, the same trade discipline our fuel business runs daily, applied to bigger and slower cargoes.
Where Vexon fits
Vexon is active in crude oil marketing alongside its refined products trade, with a bilingual desk covering the US, Mexico, and the Caribbean basin on the international side. The fuel-side companions to this page start with cross-border logistics, and the whole library lives on the knowledge hub. For crude inquiries, get in touch.