After a two-year setback, drilling operations have started again for the geothermal project of the Oil and Natural Gas Corp (ONGC) in the Puga Valley in Ladakh, India. Foundation work on the drill pad has been completed, and drilling work is expected to start soon.

The plan for the project is to drill two wells both to 1000 meters depth, where temperatures exceeding 200 °C are expected. Drilling will be completed within the current season, while the pilot phase of the thermal power plant is expected by the following season. The initial target for the project is to generate 1 MW of power.

The project is supported by a Memorandum of Understanding signed between ONGC, the Union Territory Administration of Ladakh, and the Ladakh Autonomous Hill Development Council.

Higher pressure than anticipated

Drilling in the Puga Valley geothermal project had been initiated in late 2022 following the signing of a contract with Iceland GeoSurvey (íSOR). After just a week of drilling, preliminary results were highly optimistic – high-pressure steam at 100 °C had been tapped. A separate report stated that temperatures ranging from 180 to 190 °C were found at a depth of just 40 meters.

Although positive in terms of thermal output, the high pressures and temperatures encountered also created a setback for the project. With more geothermal fluid than expected coming out of the well, some of the fluid flowed into the Puga Stream, prompting complaints from civil society and environmental organizations.

The project developers then decided to pause the project to source for more appropriate drilling equipment. For this renewed effort, the ONGC said that it has upgraded the equipment and awarded the drilling contract to SEROS Drilling Private Ltd. Experts in geothermal energy from Iceland are also on hand to provide consultancy for the project.

by thinkgeoenergy