Seismic Stratigraphic Characterization of the Upper San Andres Formation - Midland Basin, Texas

Abstract

The San Andres and Grayburg formations are prolific oil producing conventional reservoirs in the Permian Basin of west Texas. Historically, these reservoirs have produced on the structurally high Central Basin Platform with little potential for exploitation in the deeper and adjacent Midland and Delaware Basins. In these areas, a porous and permeable reservoir exists, though the charge is not present. This porosity and permeability, along with its relatively shallow setting, made this reservoir an obvious choice for produced brine injection. For the past 60 years, thousands of disposal wells have been drilled in the San Andres across the Midland Basin. However, horizontal well production in the last decade has significantly increased the disposal requirements of Permian operators. A deeper understanding of reservoir capacity and connectivity will be required to meet these demands. Pioneer Natural Resources (PXD) started a study to characterize the San Andres depositional system across the Midland Basin in 2016. The program has been supported by an effort to collect data. Pioneer has complete 3D seismic coverage over its acreage and has acquired core from three wells in the Upper San Andres. Petrophysical log coverage has also been doubled since 2016. Combining these data is crucial for the complete evaluation and characterization of the Upper San Andres. This talk will cover the resultant stratigraphic interpretation and characterization of the Upper San Andres formation within the central area of the Midland Basin. There will be a specific focus on the integration required to derive a geologically sound stratigraphic interpretation that satisfies all log and seismic based observations. In addition, the importance of seismic based rock properties for stratigraphic interpretation will be demonstrated. The products derived from this effort impact both water disposal management efforts and improve horizontal production well planning efforts.

AAPG Datapages/Search and Discovery Article #90343 ©2019 AAPG Southwest Section Annual Convention, Dallas, Texas, April 6-9, 2019