Caldwell Ranch Exploration and Confirmation Project, Northwest Geysers, CA: 2011 Geothermal Technologies Peer Review Project Summary The Caldwell Ranch Exploration and Confirmation Project was to drill, test, and confirm the present economic viability of the undeveloped geothermal reservoir in the Caldwell Ranch area. The objective of the project was to re-open and re-complete three wells abandoned in 1999 and 2000: Prati 5 (P-5), Prati 14 (P-14) and Prati 38 (P-38). The data and information collection included: (1) drilling and geology of the subject wells; (2) reservoir production flow rates, temperature, pressure, thickness, permeability, and rock fluid chemistry using new innovative combinations technologies and (3) a determination of present reservoir conditions in order to determine the feasibility of re-developing a steam supply.