Integrating provenance, facies, and diagenetic modeling for reservoir quality assessment in Cretaceous to Miocene-aged Gulf of Mexico deep water deposits

Recent hydrocarbon discoveries in the U.S. Gulf of Mexico are largely hosted within subsalt siliciclastic deep-water reservoirs. To support exploration ranking and field development, an analog-based reservoir quality prediction workflow was applied to Cretaceous through Miocene sandstones, including the Miocene, Oligocene (Frio), Paleogene (Wilcox), and Cretaceous (Tuscaloosa/Woodbine) intervals. The methodology integrates Touchstone™ diagenetic modeling with basin models to simulate compaction and quartz cementation in response to evolving temperature and vertical effective stress over geological time.

Source-to-sink dynamics in the Gulf basin have shifted with regional tectonics and accommodation space, producing sandstones that range from sublitharenite to feldspathic litharenite and litharenite composition. These provenance-driven compositional differences strongly influence compaction behavior, dissolution of unstable grains, and development of authigenic minerals such as zeolites, calcite, and various evaporite-related cements. Depositional facies further control grain size, sorting, and textural attributes that govern initial porosity and influence diagenetic pathways.

Porosity-depth trends become unreliable in settings affected by thermal or VES anomalies, particularly beneath thick allochthonous salt. Subsalt sections often exhibit cooler temperatures than predicted by regional geothermal gradients, reducing quartz cementation and yielding better-than-expected reservoir quality for a given lithology.

When supported by robust analog data, diagenetic modeling provides reliable predictions of porosity and permeability. In frontier exploration areas, uncertainties tied to burial history, provenance, and textural properties must be thoroughly evaluated. This study presents reservoir quality prediction case studies from multiple Gulf of Mexico sandstone systems, including insights from recently drilled wells.