The drilling rig has been established and drilling has kicked off.

The locations of the Wells are shown on the map :




The Drilling will be a 24 hour/day operation, seven days a week. Drilling so deeply underground can make the works program difficult to accurately schedule ahead of time. The timings and possibly the order of well drilling is subject to change and the below timeline is an approximate guideline.


  • Well 1: Drilling from October to December
  • Well 2: Likely December 2023
  • Well 3: Likely February 2024

We are very aware of potential impact on our neighbours, and work has been planned to be carried out with as little impact as possible.

This could include:

  • During the set-up and removal of the drilling rig, which will largely be in daytime hours, there will be higher traffic volume to and from the drilling sites, with up to 20 loads per day.
  • During drilling, higher than usual levels of traffic, noise or lighting around the site of each well.

If you have any questions or concerns, then please contact

This work will be carried out in accordance to consent with Bay of Plenty Regional Council and District Council resource consent conditions and district rules.







Why are we drilling more wells here?

We’ve been generating electricity from geothermal activity on the Kawerau field since 2008. During that time we’ve learned more about the geothermal reservoir deep within the earth.

Wells have a finite lifespan and corrosion can mean that wells are required to be re-drilled and replaced over time.

Therefore, as part of our sustainable management of the field, we are drilling three more wells - two production wells (takes steam and fluid to run the power station) and one reinjection well (puts fluid back).  

Are the new wells maintaining current capacity or will this mean more power/capacity?

These wells are “make up” wells – maintaining current capacity. We are drilling two production wells and one reinjection well at Kawerau.

How long does it take to drill each well?

It takes approximately 2 months for the rig to be set up, drill down, establish a well head and disestablish the rig. We are drilling three wells in the Kawerau geothermal field at this time.

What happens to the steam and fluid that comes out of these wells after it has been used by the power station?

Most of the steam and fluid is returned to the reservoir, deep underground. One of the three wells we are drilling now is a reinjection well, and there are others in the field. 

What are the rules around doing this?

This work will be carried out in accordance with Bay of Plenty Regional Council and District Council resource consent conditions and district rules. There are strict rules in place around our whole operation at the power station, including well drilling. 


What’s the size of the rig? The weight?

The drill rig is a 2007 Drillmec HH300, 272 metric ton lifting capacity and capable of drilling 5500m deep.

How is it transported?

The Rig is like adult Lego! It gets pulled apart and transported to site in ~100 truck loads and then reassembled with four cranes and a team of 30 people per day. 

Has Mercury used this rig before?

The rig has come from our geothermal power station at Rotokawa, north of Taupō, where it drilled one well (RK39) to 2200m deep.

How many people are in the drillers’ camp in Kawerau?

The rig crew is made up of 40 people, mostly New Zealanders working on a shift basis.

Local contractors have been helping us with maintenance and other activities at the Mercury power station and the geothermal field. Local contractors have also been engaged for the earthworks and waterlines associated with the drilling pads and camp.  

How can you drill accurately so far down?

While a lot of planning and science has gone in to the drilling program, these wells reach kilometres under the earth. When you’re going that deep, sometimes unexpected stuff happens and contingency plans need to be executed, which could impact the drilling schedule.

Why have you gone with IDC, an Icelandic company, to do this work?

Drilling work is very specialist, and only three other drill rigs in NZ are capable of this work. IDC have drilled in New Zealand previously in 2010-2012 (Ngā Tamariki power station) and in 2018, and most of the crew are from New Zealand. 

IDC was awarded the contract to complete these works in Kawerau as well as at the Rotokawa and Ngā Tamariki geothermal fields.



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

Geothermal wells have a small surface footprint, 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. 

Does the drilling cause earthquakes/seismic activity?

We are confident that there is no additional risk of seismic events from drilling these three deep but extremely narrow wells. In Kawerau, GNS believe that the earthquake swarm in March this year was due to the movement of active faults and not related to volcanic unrest or geothermal activity. Please see here for more information.

Will the drilling affect the water supply?

The town’s water supply will not be impacted by our activity.


What are you doing to lessen 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 such as Waiotahi contracting and Crossroads. 

How have we communicated our plans to the community?

We’ve talked to local residents, businesses and iwi who might be impacted by the drilling or moving the drilling rig around. We’ve put flyers and posters out into the community and also got the message out using social media, paid advertisements in The Echo, and our website. We will continue to communicate about our progress.

How does Mercury support the environment/community in Kawerau?

In the short term we’re proud to take our place as a supporter of the awesome Kawerau Christmas in the Park, and we’re looking to do more next year. We want to  build and continue to build good relationships in the town. We’re listening to groups in the community to understand how we can participate in the community. 

For 15 years Mercury has been running the Kawerau geothermal station, taking care of the environment above ground, and ensuring that the below-ground taonga of the geothermal field is managed and monitored for ongoing health and sustainability. 

If we have any questions or complaints, who should we contact?

You can email us at