Erha Crude Oil: Assay, API Gravity, Origin & FPSO

API gravity: 35.1°¹
Sulphur: 0.18 wt%
Acidity (TAN): 0.33 mg KOH/g
Pour point: -24 °C
Barrels per tonne: 7.41 derived²
Standard cargo: 950,000 bbl³

Evidence basis: Company-reported Company-published assay, dated 20 May 2022. Crude quality varies from cargo to cargo; in any transaction the certificate of quality for the specific lifting governs, not a published assay.

Erha: quality and origin

Erha is a light sweet deepwater crude produced about 97 km offshore through an FPSO with 2.2 million barrels of storage, operated by an ExxonMobil affiliate with Shell's SNEPCo as partner.⁴ ExxonMobil's May 2022 assay gives 35.1° API, 0.18% sulphur, a total acid number of 0.33 and a pour point of −24 °C.¹ Argus's current typical value is somewhat heavier at 33.7° API.³

Operations

The regulator attributed part of a July 2026 dip in national output to operational problems at the Erha loading buoy, resolved the following month.⁵ Reported output was 69.73 thousand b/d in May 2026.⁶

A documented regional buyer

Senegal's SAR refinery in Dakar ran "steadily" on Erha for most of 2024–25, according to Ecofin Agency, which reported the grade trading at a premium of US$2.50–3.00 per barrel to Dated Brent plus about US$1.50 freight at the time.⁷ Those figures are dated market colour, not current prices, but they illustrate the short-haul West African outlet for light Nigerian grades.

Distillation yields

Yields in vol% as published. Source: ExxonMobil, assay dated 20 May 2022.
Cut	Yield (vol%)
C5–65 °C	4.1
65–100 °C	6.1
100–150 °C	9.5
150–200 °C	9.9
200–250 °C	11.8
250–300 °C	13
300–350 °C	12.1
350–370 °C	4.3
370 °C+ residue	27.5
of which 550 °C+	5.6

Other assay values: density 848.9 kg/m³; viscosity 4.8 cSt at 20 °C; 3.5 cSt at 40 °C; nickel 4.5 and vanadium 0.2 mg/kg.¹

How published figures compare

Publishers quote different qualities for Erha because assays are run years apart on a stream whose field mix changes, and because price-reporting agencies publish rounded "typical" values. We show the figures side by side rather than silently choosing one.

Source	API	Sulphur wt%	Evidence
ExxonMobil, 20 May 2022¹	35.1	0.18	Company-reported
Argus typical, Aug 2026³	33.7	0.1798	Industry
EIA table, Nov 2025⁸	35	0.2	Government

Loading, operator and output

Loading point: Erha FPSO — see the export terminal database
Operator: Esso Exploration and Production Nigeria (ExxonMobil, operator 56.25%) with SNEPCo 43.75%; OML 133⁴
Producing area: Deepwater, about 97 km offshore in 1,000–1,200 m of water
Status: Active
Reported output: 69.7 thousand b/d — ERHA stream, May 2026.⁶ This is production by stream, not exports; part of some streams is delivered to Nigerian refineries.
Pricing basis: A differential to Dated Brent — see how Nigerian crude is priced
Volume conversion: 7.41 barrels per tonne at this gravity (our derived figure) — the barrels-to-tonnes converter has Erha as a preset
Checking an offer: A genuine Erha cargo traces back to the operator and loading point above. See who can lawfully sell Nigerian crude and the verification centre before engaging any seller

Comparable grades

The Nigerian grades closest to Erha by API gravity. The comparison tool puts any of them side by side.

Bonny Light34.9° API0.15% sulphur · Light sweet Escravos34° API0.15% sulphur · Light sweet Cawthorne36.4° APILight sweet (new grade, 2026)

Erha crude oil