Discovery Facts

Counties: Yoakum / Gaines (Wasson) and Hockley (Slaughter), Texas

Years of discovery: 1936 (Wasson) / 1937 (Slaughter)

Discovery wells: Honolulu Oil Wasson Well (1936); J.E. Guerry No. 1 Slaughter (1937)

Producing formation: Permian San Andres dolomitized carbonate

Cumulative production: ~6 billion bbl combined

Modern operator: OXY (Occidental Petroleum) on most positions; Wasson, Slaughter, Levelland, Robertson, Cedar Lake EOR portfolio

The Northern Shelf San Andres Discoveries

The 1936 Wasson and 1937 Slaughter discoveries opened the Permian Basin Northern Shelf San Andres play — a giant carbonate trend that runs across Yoakum, Gaines, Hockley, and Cochran counties in West Texas. Together with the earlier Yates discovery (1926) on the Central Basin Platform, these Northern Shelf giants established the Permian Basin as a world-class oil province.

The Wasson Field discovery is generally credited to Honolulu Oil Company’s 1936 Wasson Well. The Slaughter Field followed in 1937 with the J.E. Guerry No. 1. Both wells produced from the Permian San Andres formation — a thick, dolomitized carbonate sequence laid down in shallow shelf-margin environments during the Permian period.

Combined ~6 Billion Barrel Resource

The Wasson + Slaughter complex is one of the largest combined oil resources ever developed in North America:

Wasson Field: 4+ billion bbl cumulative; produced from San Andres / Grayburg carbonates; today operated as the Wasson ODC Unit by Occidental Petroleum

Slaughter Field: 2+ billion bbl cumulative; today operated as the Slaughter Consolidated Unit by OXY

Levelland Field: related San Andres carbonate; Levelland Unit production

Robertson Field: Northern Shelf San Andres; Robertson Clearfork Unit

Cedar Lake / Seminole / Fullerton: related San Andres carbonate units; Cedar Lake Unit, Seminole San Andres Unit, Fullerton Clearfork Unit

The Modern OXY EOR Portfolio

Through corporate consolidation over decades, most Northern Shelf San Andres production has come under Occidental Petroleum (OXY). OXY operates the modern enhanced-oil-recovery (EOR) portfolio across the trend — primarily CO₂ flooding programs that extend the productive life of these mature carbonate reservoirs by decades.

Key features of the OXY EOR portfolio:

CO₂ injection as the primary tertiary recovery method

Long reserve life on actively-managed CO₂-flood positions (decades of remaining production)

Stable, well-tenured operating quality — one of the cleanest operator profiles in the Permian Basin

Unitization consolidating fragmented mineral interests under single operating units — the modern industry standard for mature Permian carbonate giants

Modern Mineral-Owner Implications

For mineral owners on Wasson, Slaughter, or related Northern Shelf San Andres interests:

Operator quality is excellent. OXY is one of the most capable U.S. EOR operators; the CO₂ flood programs across the OXY portfolio support long reserve life and stable cash flow.

Inheritance is typically 3-4 generations deep. Original 1936-1945 lease bonus money is now received by great-grandchildren of the original Yoakum / Gaines / Hockley County signers.

Royalty checks are typically meaningful. Northern Shelf San Andres unit decimals on actively-flooded tracts often generate substantial monthly cash flow.

Unit consolidation simplifies title. OXY’s modern unit consolidation has replaced fragmented small leases with single operating units — making it easier to verify decimal interests and value future cash flow.

Selling Mineral Rights Tied to the 1936-1937 Wasson + Slaughter discoveries

If your mineral interest traces back to the 1936-1937 Wasson + Slaughter discoveries or its associated boom-era leases, Buckhead Energy can value the future cash flow stream and provide a free written offer with no obligation. Out-of-state owners are common; we handle the entire process remotely.

Texas Oilfield History Hub