Geothermal Well Drilling

GEOTHERMAL WELL DRILLING

Geothermal wells have a finite lifespan and over time wells are required to be re-drilled and replaced. We are working on an eight well geothermal drilling campaign to sustain the capacity of the Kawerau, Ngā Tamariki and Rotokawa fields. These wells are “make up” wells to maintain the current generation capacity of our geothermal power stations.

We expect to spend ~$169 million on this current “make up” well campaign. These wells are a key part of our long term sustainable geothermal generation strategy to provide base-load renewable electricity for decades to come.

Kawerau repair drilling April-August 2025

Mercury has carried out repair work on an existing well on Fletcher Avenue, near the traffic lights in Kawerau.

A well clearing process is needed to finish this work: the well is pumped through to clear out any scale.

This takes place on Friday 15 August and Saturday 16 August 8am to 6pm. The process will unfortunately result in loud noise and possibly a steam plume.

We apologise in advance for disruption from this necessary part of our operation.

FREQUENTLY ASKED QUESTIONS

What impact does drilling have on the surrounding environment - short and long term?

Geothermal wells have a small surface footprint of approximately one hectare, while extending deep underground. Short term during the drilling operation there may be higher noise, lighting and dust levels near the drill site, but in each case, this is carefully mitigated and monitored by the on-site team.

What are the rules around doing this?

This drilling work is carried out in accordance with Regional Council and District Council resource consent conditions and district rules. There are strict rules in place around our whole operation at our power stations, including well drilling.

Will the drilling affect the local water supply?

We use water for the drilling activities and these activities are part of our permits. Where drilling occurs near a town, the town’s water supply is not be impacted by our activity.

How have do you communicate your plans to the local communities?

Across all of our projects, we talk to local residents, businesses and iwi who might be impacted by the drilling or moving the drilling rig around. We may also distribute flyers and posters to inform the community of our work, as well as using local social media, local newspapers and our website.

How do you lessen the impact on the community?

We have a careful plan, including noise bunds, light barriers and dust control sprayers. There is positive impact on the community too by utilising local contractors where possible to support the specialist drilling crew.

If you have any inquiries about our geothermal power stations you can email us at geothermal@mercury.co.nz