Geopressured Geothermal – Correlations to Offshore High Pressure High Temperature Geothermal Opportunities

Abstract

The northern Gulf of Mexico basin contains geopressured zones ideal for geothermal energy production, still to be explored. These systems are defined by primarily Eocene to Miocene sands that are confined by shale beds, which facilitates the formation of anomalously high pressures and temperatures. The overpressure in these zones results in an increased geothermal gradient, which makes geopressured zones of interest for geothermal exploration. Resources are commonly found at 3 to 6 km depth and reservoir fluid temperatures can range from 90 to 200°C. There has been a substantial amount of work done to understand these geopressured reservoirs on the Gulf Coast for geothermal potential. Many of these geopressured zones extend and exist offshore in the Gulf of Mexico. The knowledge and technical success of wells completed in these geopressured zones onshore can be transferred to understand how to produce a high pressure high temperature offshore well for geothermal power production. This paper will provide a review of previous work on geopressured geothermal zones in the Gulf Coast, the challenges with these systems, how these were overcome, and the knowledge transfer of those findings for offshore geothermal opportunities in high pressure high temperature wells.