Bonga Crude Oil: 2025 Assay, API Gravity & a Heavier Stream

API gravity: 27.7°¹
Sulphur: 0.26 wt%
Acidity (TAN): 0.51 mg KOH/g
Pour point: -44 °C
Barrels per tonne: 7.08 derived²
Standard cargo: 950,000 bbl³

Evidence basis: Company-reported Company-published assay, dated 21 March 2025. Crude quality varies from cargo to cargo; in any transaction the certificate of quality for the specific lifting governs, not a published assay.

Bonga: quality and origin

Bonga was Nigeria's first deepwater development, producing since 2005 through an FPSO about 120 km offshore with roughly two million barrels of storage.⁴ It is a medium-gravity, low-sulphur crude with a very low pour point.

The stream has become heavier

Most reference tables still list Bonga at about 29° API.³⁵ The two company assays in the public domain tell a more precise story: TotalEnergies measured 29.4° API in October 2015,⁶ while ExxonMobil's March 2025 assay gives 27.7° API, 0.26% sulphur, a total acid number of 0.51 and a pour point of −44 °C, with 370 °C+ residue at 35% by volume.¹ A difference of 1.7° API changes both the barrels-per-tonne factor and refinery yield expectations, so buyers modelling Bonga on the older figure should update their assumptions.

Output and reliability

Regulator data for 2026 show Bonga at about 102 thousand b/d in May, but only 2 thousand b/d in February, consistent with a shutdown that month.⁷ A final investment decision on the Bonga North tie-back was taken in December 2024.⁸ Deepwater FPSO grades are insulated from onshore pipeline disruption, but a single-facility outage removes the whole stream.

Who buys it

India's HPCL bought a Bonga cargo from Shell in a 2026 tender.⁹ Argus reported in 2025 that the new onshore Obodo grade was expected to price in line with Bonga, which makes Bonga the reference point for Nigeria's medium sweet streams.¹⁰

Distillation yields

Yields in vol% as published. Source: ExxonMobil, assay dated 21 March 2025.
Cut	Yield (vol%)
C5–65 °C	2.3
65–100 °C	3.8
100–150 °C	6.8
150–200 °C	7.7
200–250 °C	11.3
250–300 °C	13.6
300–350 °C	13.6
350–370 °C	4.8
370 °C+ residue	35
of which 550 °C+	7.8

Other assay values: density 888.4 kg/m³; viscosity 13.9 cSt at 20 °C; 7.3 cSt at 40 °C; nickel 3.5 and vanadium 0.3 mg/kg.¹

How published figures compare

Publishers quote different qualities for Bonga 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, 21 March 2025¹	27.7	0.26	Company-reported
TotalEnergies assay, Oct 2015⁶	29.4	0.248	Company-reported
Argus typical, Aug 2026³	29.11	0.292	Industry
EIA table, Nov 2025⁵	29	0.25	Government

Loading, operator and output

Loading point: Bonga FPSO — see the export terminal database
Operator: Shell Nigeria Exploration and Production Company (SNEPCo), OML 118⁴
Producing area: Deepwater, about 120 km offshore in more than 1,000 m of water
Status: Active
Reported output: 102.5 thousand b/d — BONGA stream, May 2026 (2.02 kb/d in February 2026 during an outage).⁷ 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: 7.08 barrels per tonne at this gravity (our derived figure) — the barrels-to-tonnes converter has Bonga as a preset
Checking an offer: A genuine Bonga 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 Bonga by API gravity. The comparison tool puts any of them side by side.

Usan27.4° API0.29% sulphur · Medium sweet, high-acid Egina27.3° API0.17% sulphur · Medium sweet Nembe29° APIMedium sweet (new grade, 2023)

Bonga crude oil