| Title | Contact Energy Drilling Campaign 2005-2013 - Results, Learnings And Events |
|---|---|
| Authors | Winmill, Ralph |
| Year | 2014 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Contact Energy, Drilling, New Zealand, Wairakei, Tauhara, Ohaaki, Taheke, Development |
| Abstract | Contact Energy has completed a significant geothermal drilling campaign that stretched from April 2005 until December 2013. The initial programme planned to drill two wells with an option on four more. However as economic benefits were realised, and Contacts desire to invest further in geothermal development grew, this campaign grew to finally produce 102 wells in four geothermal fields. The drilling programme has supported the following: (1) make up drilling for the Wairakei, Poihipi and Ohaaki power stations; (2) the investment in two new power stations (Te Huka and Te Mihi); (3) one direct heat application (Tauhara Tenon); (4) an appraisal programme for the Tauhara geothermal field; (5) subsidence investigation programme for the Wairakei and Tauhara geothermal fields; and (6) exploration drilling in a green-field geothermal area (Taheke). During this campaign, numerous lessons were learned. The drilling techniques, equipment and materials used were modified and improved over the duration of the project. Significant problems were encountered with hole collapse and a variety of methods were used to overcome this particularly vexatious problem. This paper aims to describe this drilling campaign, and to summarise the learnings and changes both evolutionary and revolutionary that were made during it |