How soil gas surveys in EDC geothermal fields affect productivity

By EA Bartolo-Cruz | Geochemistry | Geosciences


QUICK READ: Geothermal energy is more efficiently monitored with the help of soil gas surveys.


At EDC, we have been studying soil gases and using the information we discover in various applications. Our soil gas studies are based on the premise that gases from a degassing magma body or a decaying radioactive material located deep below the earth’s surface will eventually find its way to the surface through vertical pathways like faults or fractures. (Figure 1)

Geothermal energy producer does soil surveys
Figure 1: Ways of escape of soil gases towards the surface of the earth

These vertical pathways tend to appear more at the earth’s surface. (Figure 2)

Geothermal energy
Figure 2: Anomalously high levels of gases concentrated in a fault

Two of the gases that we study are radon and carbon dioxide. You can find trace amounts of radon in most types of rocks, and the release of radon from rocks below the earth’s surface into these vertical pathways ensures a steady and constant supply of the gas in the surface.


As for carbon dioxide, after steam, it’s the most abundant gas that you can find in geothermal emissions, so it’s normal to find elevated levels of it above geothermal hot grounds, thermal areas, and faults.




Geothermal energy producer does soil gas surveys

Geothermal energy producer does soil gas surveys


With this idea in mind, EDC’s Geochemistry Team has been conducting a series of soil gas surveys since 2014 in Leyte, Negros, Bac-Man, and Mt. Apo. Their aim is to find areas with degassing levels that are anomalous or not normal. To do this, they measure soil gas emissions.


The data gathered from the soil gas surveys that we run is transformed into a map that will help in identifying if a surface with anomalous soil gas levels is possibly permeable or not. This is very useful for any geothermal well drilling plans, as the drilling process is expensive and any helpful information is important for decision-making.




Geothermal energy

Geothermal energy


Our soil gas studies are an inexpensive and quick way to gather more information on what’s happening below the surface of the earth. This can help us better design productive geothermal wells and identify good and bad well targets, which can help the company make better decisions that make EDC more efficient.





The Energy Development Corporation (EDC) is a pioneer in generating 100% clean, renewable, and reliable power as an electricity supplier in the Philippines for over 40 years. With power plants all over Visayas and Mindanao, the company is one of the biggest producers of geothermal energy in Asia and is expanding its reach in the international market, allowing it to offer customers affordable energy rates. EDC also strives to provide the best customer service it can to all its clients by having helpful salespeople and easy to understand contracts. Because of all of this, it is poised to become the premier supplier of electricity for the Philippines’ Green Energy Option Program. EDC takes its mission as a renewable energy provider seriously and goes beyond sustainability by investing in programs that enhance the environment and empower its partner communities, thereby fostering regenerative development. The company has also been working toward being carbon-neutral by improving its energy efficiency, as well as implementing various greening projects to ensure that its mission to provide future generations with a better life remains intact.