Exploration drilling of Kawerau Geothermal Field began in the early 1950s. Development has gradually occurred such that today up to 5 production wells supply steam for electricity and process heat to a timber mill, equivalent to about 40 MW_e. The production wells are located within an area of about 1 km², with downhole temperatures of 250 - 270°C. There has been little pressure decline as a result of production, although some shallow wells have cooled due to groundwater invasion. Proven production extends over 5 - 10 km², and low resistivity indicative of geothermal conditions at around 1 km depth extends over 20 - 35 km². The ultimate field potential is unknown, but it is clearly significantly larger than its present level of development.

In recent years, the New Zealand Government has encouraged competition in electricity generation.and supply. An electricity marketing company was set up in 1996 to oversee the trading of electricity on the spot market. Wholesale prices have typically ranged between US 2 - 5c, with short-term prices dependent demand and rainfall trends in critical hydro catchment areas. Long term price trends will be controlled by the availability of cheap gas, principally from the Maui gas field which is likely to be significantly depleted in about 10 years. Despite the competition, electricity prices should rise during the next decade, making new geothermal developments increasingly attractive commercial investment. Kawerau Field is ready for further development.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah