Te Mihi Steamfield Production Development Design

Abstract

The Wairakei Steamfield now supplies three power stations with the commissioning of Te Mihi Station in 2013. In 2008 to 2013 period the development was focused in the Te Mihi plant area to maximise energy generation from increased reservoir take. The Te Mihi zone of the steamfield has been in production since 1983, principally supplying the Wairakei Station. In 2006 the supply to Poihipi Station was added and finally in 2013, Te Mihi Station. Through this period the existing stations remained in service while the new steamfield plant was integrated into a brownfields site. Reinjection capacity was significantly increased and new zones were commissioned. Design challenges included the need to be compact to permit future production well drilling, topography, three different station inlet steam conditions, redundancy and buffer required in the reinjection system, flexibility to swing steam production amongst the stations, high steam quality, dynamic stability and maintaining production to existing stations during construction.