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.

 Mercury Geothermal Well Drilling

 

We expect to spend ~$169 million on this current make up well campaign. These make up wells are 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-May 2025

Mercury is setting up a drilling rig to carry out repair work on an existing well on Fletcher Avenue, in the car park of the Oji mill in Kawerau.

The rig will arrive on 28 April, and it will take about 12 days to set up. The drilling work will start on 12 May and run through to 26 May. When the work ends, it will take about 10 days to pack up the rig and this is expected to be completed by 8 June. 

  

Why do you need to do this work?

Over time, geothermal wells need to be re-drilled and replaced, due to build up within the pipework or because of natural fluctuations in the geothermal field. To upgrade and repair the geothermal well, a drilling rig will be set up above the well in one of Oji mill’s car parks. This will be staffed 24/7 as work takes place.

  

Will the work be noisy?

At the completion of the underground work there is a discharge test. This makes a loud noise (similar to the occasional loud noises made by the geothermal power station when it goes offline and returns to service). Depending on the weather conditions, it may also produce a plume of steam. The location of this well means that the majority of residences and businesses will not be impacted, and we will time the test during daylight hours to limit the impact on our neighbours.

  

What about traffic?

During work, there may be higher than usual levels of traffic visiting the drilling site, and the rig will be lit at night.

Work will be carried out with as little impact on the public as possible, and in accordance with the Bay of Plenty Regional Council and Kawerau District Council resource consent conditions and district rules.

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