Book Description

Results of Phase I of the Hawaii Geothermal Project (HGP), which consisted of a two-year study on the potential of geothermal energy for the Big Island of Hawaii, are reviewed. One conclusion from Phase I was that preliminary results looked sufficiently encouraging to warrant the drilling of the first experimental geothermal well in the Puna area of the Big Island. During the first two months of drilling, parallel activity has continued in all research and support areas. Additional gravity, seismic, and electrical surveys were conducted; water and rock samples were collected; and analysis and interpretation of data has proceeded. Earlier work on mathematical and physical modeling of geothermal reservoirs was expanded; analysis of liquid-dominated geothermal systems continued; and studies on testing of geothermal wells were initiated. An environmental assessment statement of HGP No. 1 was prepared and baselines established for crucial environmental parameters. Economic, legal, and regulatory studies were completed and alternatives identified for the development of geothermal power in Hawaii. Early stages of the drilling program proceeded slowly. The initial 9 7/8-inch drill hole to 400 feet, as well as each of the three passes required to open the hole to 26 inches, were quite time consuming. Cementing of the 20-inch surface casing to a depth of 400 feet was successfully accomplished, and drilling beyond that depth has proceeded at a reasonable rate. Penetration below the surface casing to a depth of 1050 feet was accomplished at a drilling rate in excess of 150 feet per day, with partial circulation over the entire range.