Utilization of Geothermal Energy in the Parrylands Field for Electricity Production

Abstract

Trinidad and Tobago (TT) was ranked as the second-highest emitter of carbon dioxide per capita in 2020. Similar to other Small Island Developing States (SIDS), TT is vulnerable to the negative effects of climate change and is also a signatory to the Paris Agreement. The use of renewable energy especially Enhanced Geothermal Systems (EGS) is receiving much attention in many parts of the world today.  Therefore, this study seeks to evaluate the possible use of EGS for electricity production by using abandoned oil and gas reservoirs in the Parrylands field located in southern TT. This study confirmed that abandoned oil and gas reservoirs in the Parrylands field in TT could utilize EGS for electricity production and CO₂ emissions reduction. A simulation model was built using CMG and the model was used to quantify the optimal amount of energy that can be produced. It also demonstrated that the cumulative enthalpy produced was higher using three-spot and five-spot configurations as well as by replacing water with CO₂ as the geothermal fluid. The results showed that the optimal cumulative enthalpy was 6.1 ´ 10¹⁰ Btu translating into a binary plant size of 0.1 MW capacity, which can be used to power approximately one hundred homes within the plant’s vicinity. By utilizing the subsidized electricity cost of US$ 0.05 per kWh, the economic analysis found an Internal Rate of Return (IRR) of 11% and a positive Net Present Value (NPV) value. Additionally, when compared to a natural gas-fired plant, the CO₂ emissions reduction potential was found to be 15,100 tons over a project lifetime of twenty years. This study clearly demonstrates the significant potential that EGS can provide when used for electricity generation by utilizing abandoned oil and gas reservoirs at the Parrylands field location.