How do you repair geothermal wells faster, cheaper, and safer?

By EC Angcoy Jr., CP Morente, JN Torres, GR Gica, GP Mendoza, and WJ Garcia | Strategic Technology and Innovation

QUICK READ: Renewable energy company EDC uses non-rig workover techniques as alternatives to a standard rig workover job.


Geothermal wells will often need maintenance and repairs, termed as a workover job. A workover typically will involve a big machine called a drilling rig but EDC continuously researches and innovates in order to apply non-rig workover alternatives that can be successful for appropriate wells:

  • Broaching gradually chips off the wellbore scales by the repetitive mechanical actions of special tools. Think of it as a subtle poking and swabbing of the well.
  • Coil tubing unit (CTU) clearing uses a long metal tube with a tool attached at the end to search and destroy the wellbore scales or deliver acid solutions to specific target areas.
  • Bullhead acidizing (BHA) injects an acidic liquid in the wellhead to dissolve common scales inside the well.

    Bullhead Acidizing

  • Offline dissolution (OffDi) is injecting in the wellhead a special chemical formulation for targeted types of scale. Unlike BHA, chemicals are less corrosive and are designed to dissolve specific scales.
  • Online dissolution (OnDi) is continuously injecting a chemical while the well remains in service. It is like taking maintenance medicine instead of going directly for invasive surgery when your artery has some blockages.

We systematically and prudently applied these technologies in our production fields. We take advantage of prolonged downtimes (such as when the wells are not feeding to power plants that are undergoing maintenance), to test them out without incurring generation losses and without damage to personnel and properties. Our teams in the Subsurface Group work together to collect and process the data, conduct simulations of risk scenarios, and plan toward a safe and successful implementation.

We continuously strive to improve and learn, drawing strength from each other and fueled by the recognition of these game-changing techniques.

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.