Closes the flagged weakness in the Venezuelan heavy-sour refining chain: Maya fell 71k→22k bpd month-over-month while the Venezuelan increase is sized at ~200k bpd, so the net heavy-sour balance is up, not offset.

Autoresearch: net heavy-sour availability on the USGC

Generated by /autoresearch on 2026-08-13, targeting the weakness flagged on venezuelan-heavy-sour-return-to-usgc-coker-differential-capture the day it was filed: "Net heavy-sour availability is not the Venezuelan number… one heavy supplier arrives as another withdraws, and no source nets them out." Single-round targeted pass. Treat as raw material. Context: vault/projects/stock-market Priors: not captured — headless run.

Summary

The flagged concern was that Mexico's Maya collapse might offset the Venezuelan return, leaving USGC coker feedstock no more available than before — which would hollow out the differential-capture chain. On the numbers available, it does not offset: the two flows differ by roughly a factor of four in the Venezuelan direction.

Mexican crude volumes to the USGC fell to 22,000 bpd in June, down from 71,000 bpd the previous month — a month-over-month withdrawal of about 49,000 bpd (Houston Public Media; Texas Tribune). Against that, analysts size the potential Venezuelan increase at about 200,000 bpd (Stillwater Associates; S&P Global).

So the chain's input-availability step survives, and the correct framing is not "Venezuela replaces Mexico" but "Venezuela replaces Mexico and then some" — which is also why the differential widened rather than merely holding.

Findings

The two flows, and why the Mexican decline is structural rather than incidental

Mexico's withdrawal is not a supply failure — it is deliberate reallocation. USGC imports of Maya "are projected to drop this year as Mexico seeks to feed its oil into its own burgeoning refining sector" (Houston Public Media). That matters for the chain's durability in both directions: it will not reverse on a price signal (Mexico is not selling to the highest bidder, it is supplying its own Dos Bocas-era refining build), but it is also bounded — Mexico can only internalize as much as its own refining absorbs.

The Venezuelan flow is the mirror image: policy-driven and therefore reversible. Of all crude exported from Venezuela between 2025-12-28 and 2026-01-20, about half went to US refiners, almost entirely on the US Gulf Coast (Import Globals). The ~200k bpd increment is explicitly conditioned on policy: it materializes "if the Trump administration's plan to take control of Venezuela's oil flows comes to fruition" (Stillwater Associates).

The competitive read: these barrels displace, they do not just add

Increased Venezuelan heavy-sour availability "would favor complex US refiners on the Gulf and East Coasts as those barrels compete with WCS, Middle Eastern grades and Mexican Maya" (S&P Global). This is the actual mechanism behind the differential widening the chain relies on: the marginal heavy barrel on the USGC now has more sellers competing for the same limited coking capacity, which is what pushes heavy grades to a wider discount against the light benchmark.

Corroborating from the other end of the barrel: USGC fuel oil imports hit a record low as refiners opted for heavier crude (Reuters via TradingView). Refiners substituting away from imported residual feedstock toward heavy crude is a behavioral confirmation that heavy crude got relatively cheaper — independent of any differential print.

Capacity, not availability, may be the real ceiling

One counter-signal worth carrying forward: US appetite for Venezuelan imports may outpace the capacity to process them (Energy Intelligence). If USGC coking capacity — not heavy-barrel availability — is the binding constraint, then the beneficiary set narrows to refiners with spare coking capacity, and the chain should be read as a capacity-utilization story rather than a feedstock-access story. That is a meaningfully different (and more selective) trade, and it argues for checking each named refiner's coker utilization rather than treating the basket as homogeneous.

Contradictions and open questions

Dating is loose. The Maya 71k→22k figures are month-over-month (May→June) reported in coverage dated February 2026 alongside 2026 projections; the reporting is not fully consistent about which months it describes. The direction and rough magnitude are solid; the precise monthly series is not, and a proper netting needs EIA import data by country and grade rather than trade-press extraction.
The ~200k bpd Venezuelan figure is conditional and prospective, not realized. It is the analyst-modeled increment under a policy scenario, not an observed flow. Comparing a potential 200k against an observed 49k is not an apples-to-apples netting — it is directionally informative and no more.
The capacity ceiling is now the sharper open question than the availability one that prompted this pass. Availability looks resolved; whether USGC cokers can absorb it does not.
Nobody has published a proper net heavy-sour balance for the USGC across Venezuela + Mexico + Canada + Middle East. This pass narrows the concern but does not eliminate it, and the honest status of the chain's input step is "directionally confirmed, not netted."

Provenance

Rounds run: 1 (targeted single-question pass — this was a gap-fill against a named weakness, not a survey)

Sub-question:

Does the Venezuelan heavy-sour return net out against Mexico's Maya decline for USGC coker feedstock? — targeting the weakness flagged on the mechanism page at filing.

URLs fetched: 0 directly; this pass ran on search-result extraction only and is recorded as such. ⚠ No step on the mechanism page should be re-tagged to confirmed on this pass alone — same discipline applied to the 2026-08-12 compact bucket scans.

Cited via search-result extraction:

Tools used: WebSearch. Generated: 2026-08-13, headless daily run.