Lithology and reservoir properties of the Delaware Mountain Group of the Delaware Basin and implications for saltwater disposal and induced seismicity

• Published in: Journal of sedimentary research Vol. 91; no. 11; pp. 1113 - 1132
• Main Authors: Smye, Katie, Banerji, D. Amy, Eastwood, Ray, McDaid, Guin, Hennings, Peter
• Format: Journal Article
• Language: English
• Published: Tulsa Society for Sedimentary Geology 01-11-2021
• Subjects: Amalgamation; applied (geophysical surveys & methods); Basins; Canyons; Carbonates; clastic rocks; deep-sea environment; Delaware Basin; Delaware Mountain Group; depositional environment; Drilling; Economic geology; Eddy County New Mexico; Encroachment; energy sources; Fluid dynamics; Fluid flow; Gamma rays; Geology; geophysical methods; geophysical profiles; geophysical surveys; Geophysics; Guadalupian; Hydraulic fracturing; Lithology; marine environment; Membrane permeability; Mountains; New Mexico; Outcrops; Paleozoic; Permeability; Permian; petroleum; petroleum exploration; Porosity; Reeves County Texas; reservoir properties; reservoir rocks; Saline water; Sandstone; sedimentary rocks; seismic methods; seismic profiles; Seismicity; Storage capacity; Stratigraphy; surveys; Texas; United States; Ward County Texas; Delaware; United States > US
• ISSN: 1527-1404; 1938-3681
• DOI: 10.2110/jsr.2020.134

Deepwater siliciclastic deposits of the Delaware Mountain Group (DMG) in the Delaware Basin (DB) are the primary interval for disposal of hydraulic fracturing flowback and produced water from unconventional oil production. Understanding the storage capacity of the DMG is critical in mitigating potential risks such as induced seismicity, water encroachment on production, and drilling hazards, particularly with likely development scenarios and expected volumes of produced water. Here we present a basin-wide geologic characterization of the DMG of the Delaware Basin. The stratigraphic architecture, lithology, and fluid-flow properties including porosity, permeability, amalgamation ratios, and pore volumes, are interpreted and mapped. Lithologies are predicted using gamma-ray and resistivity log responses calibrated to basinal DMG cores and outcrop models. Sandstones exhibit the highest porosity and permeability, and sand depocenters migrate clockwise and prograde basinward throughout Guadalupian time. Permeability is highest at the top of the Cherry and Bell Canyon formations of the DMG, reaching tens to hundreds of millidarcies in porous sandstones. Porous and permeable sandstones are fully amalgamated at the bed scale, but at the channel scale, most sandstones are separated by low-permeability siltstones or carbonates where net sandstone is less than 30%. This geologic characterization can be used to assess the regional storage capacity of the DMG and as input for dynamic fluid-flow models to address pore-pressure evolution, zonal containment, and induced seismicity.