Seequent’s software helps set a benchmark for sustainable geothermal energy development in Indonesia and supports a scheme to power 60,000 homes.
By Clare Baxter
South Sumatra is undergoing an economic boom, with electricity demand projected to surge from 925 megawatts to 1,495MW by 2030, driven by industrialisation and urban growth. Regional GDP is projected to grow at 3.8% annually between 2021 and 2030.
To meet this demand for power, Indonesia wants to further harness its vast geothermal potential.
PT Pertamina Geothermal Energy’s US$33 million Lumut Balai Unit-3 project in the Muara Enim district was initiated to provide 55 MWe of baseload renewable power by 2029, contributing to both regional energy security and more broadly to the nation’s Net Zero Emissions target by 2060.
As well as saving 300,000 tonnes of carbon dioxide annually and reducing fossil fuel dependency by 2,600 barrels of oil equivalent per day, the project will electrify approximately 60,000 remote households and improve regional accessibility through a 7km access road linking the villages of Penindaian, Babatan, and Semendo.
Geothermal development can be fraught with uncertainty. Traditional exploration methods often involve disconnected datasets, manual workflows, and a reliance on software not specifically designed for complex volcanic geology. This leads to lengthy feasibility studies and, most critically, a high drilling risk.
Initial estimates for the Lumut Balai project put the drilling risk at 48%, threatening its viability and the production of essential clean energy. Pertamina turned to Seequent, The Bentley Subsurface Company, to be able to see into the subsurface with greater clarity in order to reduce investment risks and speed up construction.
Establishing a new benchmark
Drilling of Lumut Balai is scheduled to begin in early 2026 with commissioning anticipated by mid-2029.
PT Pertamina Senior Geoscientist Vivi Dewi Mardiana Nusantara said integrating Seequent’s Leapfrog Energy, Oasis montaj, and Volsung enabled the real-time construction and refinement of three-dimensional geological and conceptual reservoir models.
A reliable subsurface geothermal model identifies resource location, estimates its potential, and evaluates associated risks. Courtesy of PT Pertamina.
As a consequence, the length of the feasibility study phase was cut in half, to six months.
‘This data-driven approach supported cross-disciplinary collaboration and allowed for the delivery of 15 deep geothermal well designs within 4,800 productive working hours.
‘A customised Play Fairway Analysis (PFA) workflow within Leapfrog successfully prioritised well targets, reducing drilling risk from 48% to 15% by incorporating geological structure, alteration mineralogy, fluid pathway indicators, geophysical data, reservoir pressure and thermal-gradient constraints.’
A robust model is an invaluable tool when operating in complex subsurface conditions. Courtesy of PT Pertamina.
Cutting the drilling risk by such a significant degree helped establish ‘a new benchmark for efficient, sustainable energy development in the region’, she said.
That translated into a US$1.5 million saving in terms of drilling costs alone.
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Improving collaboration and decision-making
Going digital had significantly transformed the way geothermal projects were carried out, she said, ‘replacing traditional, manual workflows with integrated data-driven platforms designed specifically for geothermal analysis’.
Traditionally, these had used ‘paper-based methods, basic tools, and limited software adapted from the oil and gas industry’, leading to inefficiencies and disconnected data processes.
‘This shift has enabled faster decision-making, seamless collaboration, and real-time data integration across teams.’
One of the approach’s most useful benefits was having the ability to access, update, and manage data ‘anytime, anywhere, enhancing transparency, agility, and project efficiency across all stages of development’.
By integrating multidisciplinary tools, the project translates complex data into clear insights, making it accessible and impactful for all stakeholders. Courtesy of PT Pertamina.
‘With its scalable and replicable approach, the project not only supports South Sumatra’s growing energy needs but also sets a precedent for data-driven geothermal initiatives aligned with national and global sustainability targets.
‘From millions of data points of microscopic epidote mineral to a massive caldera model, Seequent’s geothermal modelling tools bring the entire subsurface to life efficiently and accurately in one digital environment, enabling faster interpretation, better collaboration, and more confident decision-making across all scales,’ she said.
Fast facts:
- Supplying 55MWe of clean energy to 60,000 homes;
- Reducing drilling cost from US$9 million to US$7.5m;
- Cutting potential carbon dioxide emissions by 300,000 tonnes a year;
- Potentially saving 2,600 barrels of oil per day.