| Abstract |
Co-produced water is water produced as a by-product during oil and gas production. Previous studies have estimated that 15-25 billion barrels of water are co-produced during oil and gas operations annually in the United States. Some well fields produce enough water at high enough temperatures that they could be used to produce electricity. Further, some have speculated that the total electricity generation potential of co-produced water resources in the United States could be tens of gigawatts. This study estimates the near-term market electricity generation potential of water produced as a by-product from active oil and gas operations. The study focuses on the near-term market potential of the coproduced resource and only considers co-production from existing oil and gas operations. A database consisting of oil and gas well data from across the United States was created by aggregating information from state oil and gas well databases. In all, oil and gas databases from 24 states determined to have significant oil and gas activity were aggregated, resulting in a co-production database containing records from 2.5 million wells, half a million of which were identified as active, producing wells. Then, a Geographic Information System (GIS) was developed to combine oil and gas well location, depth, and water production information with geothermal resource maps to estimate the co-produced water temperature. Coproduced water temperatures were estimated based on maps created from a separate database containing the bottom-hole temperature of 27,000 wells and from temperature-at-depth maps developed by the Southern Methodist University Geothermal Laboratory. Models were developed to calculate the power generation potential of the co-production resource based on the co-produced water volume and temperature estimates. A cut-off temperature for electricity production of 176° F (80° C) was assumed. Several scenarios were explored to determine the sensitivity of the resource potential estimate to assumptions and results from t he study. Over 60% of active wells in the database were found to have estimated temperatures of less than 176° F (80° C). Nearly 20% of the active wells lack sufficient data (primarily well depth) to make a temperature estimate. Although the study indicates that there are a significant number of oil and gas operations with sufficient temperatures and co-produced water volumes that could potentially be utilized for electricity generation, it was concluded that the near-term market potential for the co-production resource as a whole is roughly 300 MWe. This estimate does not take into account practical operational factors such as a minimum power plant size, availability of cooling water or transmission, project economics, etc., that could further limit the number of sites that could be developed. The majority of the co-production resource potential is in Texas, which accounts for roughly two-thirds of the near-term electricity generation potential. Given the size of the Texas co-produced resource potential rel ative to the rest of the United States and that co-produced water data for Texas was based on reported re-injected water volumes, a more thorough study based on actual well data is recommended. |