Injection related cooling in the Unit 13 area of the Southeast Geysers, California, USA

摘要

Eight years of water injection into southeast Geysers well CA 956A-l has been beneficial and without any water breakthrough to nearby producers. Production wells with maximum injection benefit did not show any wellhead temperature or enthalpy degradation for approxi- mately five years. Production wells which showed no obvious injection effect did not exhibit any thermodynamic degradation for up to six years. Producers located to the northwest of CA 956A-1 have not displayed any thermal degradation so far. The thermal front appears to grow towards the southwest and east of the injection well. Upon arrival of the thermal front, a drop of 1.3-5.7 deg F (0.7-3.2 deg C) per year in wellhead temperature and 0.32-2.3 Btu/lbm (0.7-5.3 kJ/kg) per year in wellhead enthalpy has been observed. The arrival of the thermal front signifies a slowing down in boiling rate and, therefore, the recovery rate of the injected water.