| Abstract |
All Wairakei well measurements have been reviewed and re-interpreted. In its natural state the field contained a liquid dominated tow phase zone over a deeper liquid reservoir. The initial pressure distribution was about 10% above hydrostatic, the excess gradient driving the natural discharge. With exploitation and falling pressure, the two phase zone expanded downwards, and within it a vapor dominated zone developed. The changes with exploitation can be characterized by two pressure: a deep liquid pressure, reflecting mainly the reservoir mass balance, and a pressure in the steam zone, reflecting the reservoir heat balance. The heat balance indicates that most, but not all, of the recharge is hot water. |