Western Midstream Partners, LP Supply Chain: OXY & Williams Dominance Exposed

Oxy and Williams Companies control 63% of WES’s top customer volume and are its largest supplier, creating a high-stakes dependency that could amplify both upside and downside risks.

Deep Mutual Dependency with OXY

Occidental Petroleum (OXY) is WES’s most critical relationship, appearing as both a top supplier (80% confidence) and top customer (90% confidence). The SEC filing confirms a "reciprocal relationship" where WES transferred 15.3 million units to OXY in February 2026, recording a $105 million charge. This isn’t just transactional—OXY is the dominant force driving WES’s Granger complex throughput (81% from OXY and two other top customers), and WES processes OXY’s gas at the Red Desert complex (59% from top three customers).

Customer Concentration: Granger Complex is a Single-Source Bet

WES’s Granger complex relies on just three customers for 81% of throughput. OXY leads this cluster, but the SEC filing names "Crescent Energy (CRGY)" and "The Williams Companies (WMB)" as the other top buyers. WMB is also a direct customer at 92% confidence, delivering residue gas to WES’s pipelines. If OXY or WMB scales back operations—due to market shifts or internal restructuring—WES faces immediate revenue erosion at its highest-volume asset. The Williams relationship is especially vulnerable: WES delivers residue gas to WMB’s MountainWest and Northwest Pipelines, meaning a slowdown in WMB’s pipeline utilization directly impacts WES’s throughput.

Supplier Risks: Anadarko & OXY Control Input Flow

WES’s primary gas supply comes from Anadarko-E-P-Onshore-LLC (90% confidence), confirmed in a Delaware Basin gathering agreement. Crucially, OXY also supplies gas to WES at 80% confidence, creating a dual dependency on a single oil producer. If OXY curtails production or negotiates unfavorable terms (as seen in the 2026 unit transfer), WES could face supply chain disruption. This is compounded by the fact that OXY is WES’s largest customer—any input disruption could cripple WES’s ability to meet demand, risking contractual penalties with OXY and WMB.

Who Benefits & Who’s Exposed

If WES outperforms, OXY benefits from reliable gas processing and transport (critical for its Permian Basin output), while WMB gains access to low-cost residue gas for its pipeline network. Conversely, if WES struggles, OXY faces pipeline bottlenecks that could delay gas sales, and WMB risks losing access to its Granger complex feedstock. The $105 million 2026 unit transfer to OXY signals strategic alignment—meaning WES’s success is now tightly tied to OXY’s Permian growth. Failure to secure new customers beyond OXY and WMB (like ONEOK, Targa, or Energy Transfer) would leave WES exposed to sector-wide downturns in oil and gas midstream demand.

What to Watch

Monitor OXY’s 2026 Delaware Basin gas processing agreement with WES for renegotiation terms. Track WMB’s MountainWest Pipeline utilization rates as a proxy for WES’s Granger complex demand. Watch for new customer contracts beyond OXY, WMB, and Targa Resources (TRGP), which appears as both a supplier and customer at 72% confidence. Without diversification, WES remains vulnerable to a single counterparty’s performance.