The feasibility of geothermal energy extraction in Sarawak

By Dr. Mahmood Bathaee

Recently, our team at Curtin Malaysia implemented a study on the feasibility of utilising geothermal energy from the Baram Basin in Sarawak. This exploration is timely and critical in the era of seeking environmentally-friendly and sustainable energy sources. Geothermal energy, which harnesses the Earth’s internal heat, offers a promising alternative to traditional fossil fuels, aligning with global efforts to combat climate change and reduce air pollution.

The Baram Basin, known for its rich history of oil and gas exploration spanning over a century, presents an intriguing opportunity for geothermal energy extraction. This long history has led to the accumulation of extensive geological data, making the basin an ideal candidate for this type of research.

The available data includes detailed records from seismic surveys, well logs, and various geological studies, providing a comprehensive understanding of the subterranean conditions. The availability of such rich data is crucial for assessing the potential of geothermal resources in the area.

Existing subsurface data and locations of fields

Asam Paya estimated range for geothermal gradients

The study employed a series of computer simulations to predict the feasibility and efficiency of extracting geothermal energy. These simulations are pivotal in understanding the dynamics of geothermal reservoirs, including how heat is stored and transferred within the Earth.

Factors such as the porosity of rocks, initial temperature conditions deep underground, and the permeability, which refers to how easily water can move through the subsurface rocks, were meticulously analysed. These elements are critical in determining the energy output that can be expected from the geothermal reservoir.

Temperature profile in the reservoir after production

Among the notable findings of the research, the determination of optimal well spacing emerged as a key aspect. The study concluded that a 300-metre distance between wells is most effective for sustainable heat extraction. This spacing is crucial in maintaining a balance between extracting enough heat to generate electricity and ensuring the reservoir’s longevity by avoiding excessive cooling.

Another significant aspect of the study was the observation of the energy production lifecycle. Initially, high levels of energy output were noted, attributed to the extraction of naturally stored heat. However, over time, this output was observed to decrease, a phenomenon linked to the injection of cooler water into the reservoir, which is a common practice in geothermal energy extraction to maintain pressure and sustain production.

Enthalpy of production (rate and cumulative) in the field versus years of production

The economic feasibility of geothermal energy extraction from the Baram Basin was also a focal point of the study. An in-depth economic analysis, including the comparison of the Levelized Cost of Electricity (LCoE) from geothermal sources against other traditional and renewable energy sources, was conducted. This analysis is crucial in understanding the commercial viability of geothermal energy in comparison to more established energy sources.

Additionally, a comprehensive sensitivity analysis was carried out to identify potential risks and uncertainties associated with geothermal energy extraction. This analysis is vital in gauging the reliability and predictability of energy output, considering various geological and operational variables. The study thoroughly examined the impact of different factors on the cumulative energy production, providing insights into the robustness of geothermal energy projects in the region.

In conclusion, the research paper posits that the Baram Basin holds significant potential as a geothermal energy source. However, it underscores the importance of further detailed investigations. These should focus on optimising the extraction techniques and a deeper understanding of the aquifer dynamics, which involve the movement and characteristics of water in the subsurface layers. Such studies are essential for maximising energy production while ensuring environmental sustainability.

Overall, this study marks a significant step forward in understanding the potential for renewable energy extraction in the Baram Basin. It highlights the importance of in-depth geological and economic analysis in the development of sustainable energy sources. For those seeking a comprehensive understanding of the methodologies employed and the specific findings, a detailed review of the original research paper is highly recommended.

Dr. Mahmood Bathaee is an accomplished Petroleum Engineering academic and researcher who began his academic career in 2003. He earned a bachelor’s degree from Iran’s Petroleum University of Technology in 2007, followed by a master’s degree from the same institution in 2010, and a PhD from Universiti Technologi Petronas in 2016. Dr. Bathaee’s career has included being a petroleum engineer with the Iranian Offshore Oil Company, and lecturer and researcher at various universities, including his current role at Curtin Malaysia. His research, reflected in many journal publications and conference proceedings, spans a broad spectrum of petroleum engineering topics, including drilling engineering, well design, production engineering, and more. Notably, his work delves into areas like nano-materials in drilling mud, geothermal energy production, and CO² storage. Additionally, he has conducted significant research in deep learning applications in petroleum engineering, and has secured funding for environmentally-focused projects. Dr. Bathaee is also an active member of professional bodies such as the Institution of Mechanical Engineers (IMechE) and Society of Petroleum Engineers (SPE). He can be contacted via email at mahmood.bathaee@curtin.edu.my.