| Title | Geothermal Resource Assessment of the Commonwealth of the Northern Mariana Islands |
|---|---|
| Authors | Leland Roy Mink, David Blackwell, Maria Richards, Al Waibel |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Mariana Islands- Pagan, Saipan, exploration |
| Abstract | Facing increasingly higher cost of diesel-generated electrical power, the Commonwealth of the Northern Mariana Islands (CNMI) government initiated an assessment of geothermal energy potential on the islands. As part of this effort, the Southern Methodist University Geothermal Team visited the CNMI Islands of Pagan and Saipan. The team was on Pagan from March 5 to 11, 2008, to conduct a preliminary assessment of the geothermal resource potential of the Island, which was selected for assessment because of its size, proximity to Saipan, relative accessibility, and characteristics of volcanic activity. These suggest the potential for a significant geothermal resource. The team then conducted an assessment of Saipan from March 12 to 18 which involved geologic assessment and logging of selected water wells. The assessment is based on helicopter and ground surveys and analysis of samples of rock, water, and gas. New and previously existing data indicate the presence of a geothermal reservoir on the southwest side of South Pagan which has a minimum temperature of 194 °C (385 °F). The size of the field(s) is estimated to be a minimum of five to eight square kilometers with an electric generating capacity in the range of 50 - 125 MW based on the surface area and fluid chemistry. Reconnaissance geologic and geo-chemical studies were conducted on Saipan following the work on Pagan. These studies included spring sampling for geothermal indicators and temperature logging of selected wells to determine geothermal gradients on the island. Saipan does not have the young volcanic rocks to form a high temperature geothermal system but deep faulting may allow thermal waters from greater depths to migrate upward for a low to medium temperature resource. A deeper thermal gradient well is scheduled to be drilled on Saipan in quest of additional information. |