Middle East and Gulf of Oman Dark Crude Exports Methodology

Analyst Note: The figures referenced in this section reflect data as of June 11, 2026. More recent periods will have changed as new evidence is received and records are updated.

The closure of the Strait of Hormuz on 28 February 2026 cut off the primary outlet for roughly a fifth of global seaborne oil. Tankers could not exit the chokepoint. Barrels piled up. Crude floating storage inside the Gulf spiked from around 2 Mbbl pre-conflict to a peak above 94 Mbbl by late April.

Producers responded by leaning on the limited bypass capacity that sidesteps the Strait. Saudi Arabia rerouted barrels west through the Petroline to Yanbu, lifting Red Sea crude exports from 1.2 Mbd in February to 4.7 Mbd by April. The UAE, whose ADCOP pipeline delivers Murban directly to Fujairah on the Gulf of Oman, ramped up liftings from 1 Mbd to 1.8 Mbd over the same period. These routes absorbed a large share of displaced volume, but their throughput is finite.

As bypass pipelines approached capacity, a third channel emerged: a shuttle corridor of dark transits and ship-to-ship transfers in the Gulf of Oman. Combined non-Iranian crude movements through Hormuz and Gulf of Oman export channels totaled nearly 140 Mbbls since the start of April, equivalent to roughly 1.9 Mbd through June 11. From May through June 11, those flows averaged 2.4 Mbd. By comparison, pre-conflict non-Iranian crude transits sat at 13.2 Mbd in 2025, highlighting how severely constrained flows remain.

As visible transits via the Iranian route vanished, combined dark transits and Gulf of Oman STS operations accounted for more than 80% of all non-Iranian crude trades from the Mideast Gulf by May.

The visual below illustrates the complete migration of volumes away from the visible Iranian route to hidden offshore shuttle rings:

Kpler has identified four distinct patterns through which crude originating from Mideast Gulf terminals has been moving since the disruption began. These mechanisms differ in their AIS behaviour, routing mechanics, and the nature of the evidence available to confirm each step.

Before describing how each mechanism works, it helps to understand a few terms used throughout this note.

AIS (Automatic Identification System) is a transponder fitted to commercial vessels that broadcasts position, speed, and identity in real time. When a vessel switches its AIS off, it becomes invisible to conventional tracking. This is referred to as "going dark."

Ship-to-ship transfer (STS) is an operation in which cargo is transferred directly between two vessels while at sea. The vessel delivering the cargo is referred to as the mother vessel. The vessel receiving it is referred to as the daughter vessel.

Dark transit refers to a vessel transiting the Strait of Hormuz with its AIS switched off, making the crossing undetectable through standard vessel tracking.

A vessel loads at a Mideast Gulf (MEG) terminal and transits the Strait with AIS transponder active, using the northern Hormuz corridor through Iranian territorial waters near Bandar Abbas.

It is important to note that there are multiple routes that Kpler tracks. Pre-conflict saw vessels transiting the strait following the IMO Route, however at the time of writing, no crude exports have been registered as taking the IMO Route since 11 March.

A vessel loads at a MEG terminal, deactivates AIS at or before the Strait, transits the chokepoint without broadcasting, and proceeds directly to its destination. Typically the vessel will resume AIS once clear of the region.

Confirmation of the loading event requires a market intelligence source reporting the load, corroborated where possible by satellite imagery confirming the vessel at the terminal in a laden state. Confirmation of the transit requires satellite imagery showing the vessel inside the Gulf on one date and outside on another, or AIS evidence that brackets a gap consistent with a transit window.

No destination is assigned until independently confirmed through AIS resumption and vessel movement, or through destination port reporting from vetted sources confirming the vessel's arrival. Kpler does not infer destinations from vessel history or cargo routing patterns.

A mother vessel loads inside the MEG, transits the Strait, and conducts a ship-to-ship transfer in the Gulf of Oman; all whilst dark. The STS typically occurs around Fujairah Light or Sohar Light, before the cargo continues onboard a daughter vessel.

This is Kpler's most operationally complex tracking scenario. For this type of trade to be confirmed, three conditions must hold:

When all three conditions are met, the trade is attributed to the origin country of the confirmed load terminal. The crude grade confirmed for the mother vessel is inherited directly by the daughter. The daughter is then typically tracked forward through more conventional means, effectively giving the full picture of the trade from origin to destination.

In some cases Kpler has confirmed a mother vessel loading inside the Mideast Gulf and transiting the Strait via satellite imagery, but cannot identify the daughter vessel receiving the cargo in the Gulf of Oman. In these instances the mother vessel is subsequently observed returning to load inside the Gulf again, confirming the shuttle pattern.

Where the STS cannot be directly evidenced and the daughter remains unidentified, Kpler records this as a discharge onto an unknown vessel in the Gulf of Oman rather than a confirmed end-to-end trade. The origin and grade follow the confirmed mother vessel load, but the receiving vessel and onward destination remain unattributed until further evidence is available.

A vessel in the Gulf of Oman receives cargo via STS, evidenced by a draft change consistent with loading, or by intelligence confirming an STS event. However in this case no traceable upstream can be established: no confirmed MEG loading, no confirmed Strait crossing, no identified mother vessel.

Kpler records these as Gulf of Oman STS trades with origin classified as Unknown and grade as a generic Middle East crude designation. In these cases the potential STS is the inferred mechanism rather than a confirmed event: the vessel is observed laden in the Gulf of Oman, but the transfer itself is not directly evidenced. In addition, the cargo could equally have loaded inside the Mideast Gulf and transited dark.

Records are updated iteratively as further evidence becomes available, whether grade identification at the discharge port, satellite confirmation of a mother vessel, or retrospective market intelligence linking the cargo to a specific upstream loading.

One of the most important features of Kpler's data is the separation between what the evidence strongly suggests and what can be confirmed at vessel and cargo level. This distinction is especially relevant for Gulf of Oman flows classified as unknown origin.

The balance of evidence suggests that the UAE is the primary source of many unknown-origin Gulf of Oman flows. SAR imagery has been particularly important in identifying likely loading activity. Grade identifications across nearly 50 Mbbls of April and May trades indicate that more than 80% originated from UAE terminals. Kpler has observed similar dark-transit and shuttle behaviour linked to other Mideast Gulf producers, including Iraq and Kuwait, but the evidence remains most consistent for UAE-linked flows.

Despite this, Kpler does not automatically convert likely UAE-linked activity into confirmed UAE-origin exports. SAR can indicate that a loading likely occurred, but it does not always identify the vessel or establish the full cargo chain. Grade identifications corroborate origin, but do not by themselves prove which tanker carried which barrels through the system.

This is why the Gulf of Oman unknown-origin bucket exists. It preserves the difference between what the evidence strongly suggests and what can be confirmed at vessel and cargo level. Without that distinction, there would be a risk of either undercounting flows by ignoring dark activity, or overstating certainty by attributing origin where the full cargo chain has not been proven.

Kpler's approach is intentionally cautious. No single source is considered sufficient on its own for dark transits or offshore transfer activity. Instead, Kpler looks for consistency across AIS signal analysis, satellite imagery, SAR imagery, market intelligence, and import-side confirmation before making an attribution. Once a load terminal is confirmed, the cargo is attributed to the producing country of that terminal regardless of how it subsequently moves. If the cargo changes vessels, the confirmed grade and origin carry through to the receiving vessel, but only when the transfer chain is sufficiently evidenced. Where that chain is incomplete, the cargo remains of unknown origin.

The practical effect is that Kpler's published figures should be read as a high-confidence floor for observed and confirmed activity, not as a speculative estimate of everything that may have moved. Some volumes may later be reassigned as clearer information becomes available. Until then, the data remains deliberately conservative.

The confirmation standard applied across all four mechanisms is binary: a loading, crossing, or STS event is either confirmed by sufficient and consistent evidence across these sources, or it is not recorded as confirmed. Kpler does not apply probabilistic attribution, we do not record a trade as originating from a specific country on the basis of vessel history, expected routing patterns, or cargo profile inference alone. A portion of actual export activity will therefore sit in the unattributed GoO STS bucket until evidence becomes available to resolve it. This is an accurate reflection of the information available, not a coverage gap.

The following summarises the key principles governing what Kpler confirms and what it does not assume when tracking MEG crude flows under the current disruption environment. These principles apply consistently across all four mechanisms.

When combining Mideast Gulf transit data with Gulf of Oman STS data, there is a potential risk of counting the same cargo twice. This can occur if a shuttle tanker loaded inside the Mideast Gulf is counted as a Mideast Gulf export, and then the daughter vessel receiving the cargo in the Gulf of Oman is separately counted as a Gulf of Oman export. Without establishing the link between mother and daughter vessel, the same barrel could appear in both views.

First, rather than using the standard Mideast Gulf export view, Kpler uses the Strait of Hormuz transit view. Vessels confirmed to have loaded in the Mideast Gulf will not automatically carry a Strait of Hormuz transit tag. A crossing must be independently evidenced before a transit is recorded. Without that confirmation, the vessel does not appear in the transit view. This helps exclude shuttle tankers that are still part of an unresolved STS chain.

Where a vessel carries a confirmed transit tag but the daughter has not yet been identified, the link is typically established over time, removing the duplication. In other cases the vessel is ultimately confirmed as the long-haul carrier itself, again avoiding double counting.

Second, rather than using outright Gulf of Oman exports, Kpler uses net exports. The calculation takes confirmed unknown exports leaving the GoO aboard long-haul vessels heading to discharge, and subtracts unknown imports arriving into the GoO aboard shuttle tankers with unmatched STS partners. What remains is the net outflow: cargo genuinely departing the region that has not already been counted elsewhere. This prevents the same barrel from being counted both as a Strait of Hormuz transit and as a separate Gulf of Oman export.

A residual edge case exists where a shuttle carries a confirmed transit tag and discharges to a daughter in the GoO, but the two cannot yet be linked. The daughter surfaces as a GoO unknown loader and the same barrel appears in both the transit view and the net exports layer. The same barrel now appears in both views.

Kpler minimises this by actively linking confirmed GoO discharges back to their shuttle tankers wherever the evidence allows. Where a shuttle proceeds as the long-haul carrier itself rather than conducting an STS, no daughter vessel is created and the risk does not arise at all.

As linkages are confirmed over time, affected records are corrected. Figures may therefore be subject to minor fluctuation in recent periods.

Use Mideast Gulf (excl. Iran) transits via Strait of Hormuz, Crude/Co, split by origin country. Note that dates here reflect the transit date, when the crude physically moved out of the Gulf, rather than the loading date.

Use Gulf of Oman net exports, Crude/Co, split by grade. This captures cargo received from unknown vessels in the Gulf of Oman where origin cannot be confirmed to a specific Mideast Gulf terminal. This is additive to the transit view above with no double counting.

Sum the two queries above by month. This gives the most complete picture of non-Iranian Mideast Gulf crude moving through Hormuz or via the Gulf of Oman shuttle corridor, excluding Fujairah exports.

Why does Kpler's UAE export figure differ from other data providers?

How do I construct a complete UAE export figure?

Can you confirm these GoO barrels are coming from the Persian Gulf and not Fujairah?

Why is the crude grade listed as generic Middle East crude for GoO STS trades?

Why can’t Kpler sometimes identify the grade loaded from FOTT?

How does Kpler use satellite imagery to confirm STS activity?