Future Production Strategy - Ohaaki Geothermal Field

Abstract

The geothermal reservoir had excess steam capacity at commissioning of the power plant. The available steam flow has declined steadily and has now fallen below the level required to fully load the turbines. A study has reviewed options for either increasing the steam supply by drilling additional wells or maximising electrical generation from existing wells. It was concluded that the reservoir currently utilised can not support additional make-up wells. A combination of a sliding reduction of high pressure turbine inlet pressure and de-rating individual wells to intermediate pressure was considered to be the best strategy.