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San Mateo plans a 300 MMcf/d Marlan processing train, nitrogen-rejection unit, field carbon-dioxide treating facility and about 20 miles of Delaware Basin pipeline, with target completion at year-end 2028.
Published by Allstream Insiders
Allstream Insiders Summary
San Mateo Midstream has announced long-term gathering and processing agreements that support a planned expansion of its Delaware Basin system in southeast New Mexico. According to the company’s November 2 announcement, the planned scope includes a 300 MMcf/d gas-processing train and nitrogen-rejection unit at the Marlan Plant complex in Eddy County, approximately 20 miles of new gas pipeline, and a field treating facility for carbon-dioxide removal.
San Mateo is targeting year-end 2028 for completion, subject to routine permitting, procurement and construction. The company did not describe the expansion as a final investment decision, and the release does not disclose a total project budget, engineering contractor, equipment manufacturer, construction contractor, pipeline route or line size.
Expansion at a glance
| Item | Company-reported detail |
|---|---|
| Processing capacity addition | 300 MMcf/d at the Marlan Plant complex |
| Other plant scope | Nitrogen-rejection unit and field carbon-dioxide-removal treating facility |
| Gathering scope | Approximately 20 miles of natural-gas pipeline |
| Target completion | Year-end 2028, subject to stated conditions |
| Contractor and supplier awards | Not disclosed |
What the new agreements cover
One new agreement is a long-term, fixed-fee arrangement for San Mateo to gather and treat gas from newly dedicated acreage in Lea and Eddy Counties, then process it at Marlan. The producer was not named. San Mateo described the dedication as large scale but did not disclose acreage, committed volumes, contract length or commercial terms.
A separate extension continues an existing Black River Plant gathering and processing agreement for gas from Eddy County for several years beyond its original term. San Mateo said that extension is expected to add long-term value with no incremental capital expenditures. The new Marlan and gathering work is a separate capital program designed to serve the new agreement and anticipated Matador volumes.
Processing, pipeline and treating scope remains in development
The release identifies the high-level physical scope but not the configuration or procurement plan. It does not provide the pipeline’s route, diameter, inlet and outlet points, gas composition, treating technology, project cost or construction sequence.
San Mateo said its total processing capacity would exceed 1.3 Bcf/d once the expansion is complete. That is a forward-looking target that depends on completion of the announced work; the release does not disclose a total capital budget for the expansion.
Cardinal integration adds a separate 2027 milestone
San Mateo also said it plans to complete a northern connection in 2027 between its Lea County gathering infrastructure and the terminus of the Cardinal gathering system in Eddy County. The company said this would create flexibility to move gas between the Marlan complex in the north and the Pecos River Plant in the south. The announcement does not provide mileage, cost, permits, contractors or a defined construction schedule for that connection.
What could be involved if the project moves into execution?
Allstream perspective: A project of this type could require engineering and design, survey and right-of-way support, line pipe, valves and fittings, metering and controls, civil work, welding, testing, electrical systems, instrumentation, equipment rental, insulation, coating and painting. The processing and treating facilities could also call for specialized gas-processing, nitrogen-rejection and carbon-dioxide-treatment equipment, depending on the final design.
Those are potential work categories, not announced contracts or confirmed packages. San Mateo has not identified the EPC contractor, line-pipe supplier, equipment manufacturers, technology providers or construction firms.
Allstream perspective: Defined scope, but no award disclosures
The long-term agreements provide commercial support for a more specific processing, treating and gathering expansion than a general capacity-growth statement. The 2028 target makes Marlan a project to track, but it remains subject to permitting, procurement and construction.
Next decision-useful updates would include a final investment decision, project budget, regulatory milestones, pipeline specifications, equipment orders, engineering awards and construction contracts.






