Co-producing Geothermal Power from Oil and Gas Operations: A Case Study from Alberta, Canada

Abstract

This paper discusses the challenges and opportunities of the pioneering co-produced geothermal power plant project in Swan Hills, Alberta, Canada. The project leverages the existing infrastructure of high thermal gradient reservoirs, where the bottom hole temperatures range from 110 to 120 degrees Celsius, to generate electricity through an integrated generation system employing both a binary Organic Rankine Cycle (ORC) power plant and a natural gas-fired turbine (NGT). The ORC power plant converts geothermal heat and NGT waste heat into power. The project has a nameplate capacity of 21 MW, of which 4 to 6 MW are derived from renewable geothermal and waste heat sources. This reduces greenhouse gas emissions by up to 398,000 tonnes of CO2 over a minimum twenty-year plant operation life. The project demonstrates the economic feasibility of repurposing existing hydrocarbon infrastructure for sustainable energy initiatives. The paper also addresses the reservoir characteristics, the reservoir temperature measurement methods and estimates, and the project performance indicators. It shows how the project utilizes a geothermal hot spot within the Western Canadian Sedimentary Basin to produce electricity from a high thermal gradient reservoir with high permeability and porosity. We also examine the technical and regulatory challenges faced by such projects in North America. We discuss how the project integrated the ORC system with the NGT, how it coped with supply chain disruptions, transportation delays, budget inflation, and COVID-19-related constraints. We also address the concerns about the sustainability of geothermal energy from oil and gas facilities, which often face funding and regulatory challenges due to the perceived contradiction between fossil fuels and renewable energy sources. The paper explains how these challenges were overcome by comprehensive testing, collaboration with expert engineers and suppliers, and contingency planning and risk mitigation. The paper provides an assessment of the project, and the lessons learned that can guide future geothermal endeavours. The paper aims to contribute to the advancement of geothermal energy development from deep reservoirs and existing hydrocarbon infrastructure, both in Canada and globally.