| Title | The Resistivity Structure of the Mahanagdong Geothermal Field, Leyte, Philippines |
|---|---|
| Authors | Carlos Emmanuel F. Los Banos and Felixberto C. Maneja |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | Magnetotelluric, Mahanagdong Geothermal Field |
| Abstract | been experiencing problems on injection returns and pressure drawdown in the center of the field, causing the decline of steam supply in this sector. A long-term solution to sustain the 180 MWe steam requirement, is to look for drilling targets in other areas than the current production block. A magnetotellurics (MT) survey was then conducted in 2001 to delineate the resistivity structure of Mahanagdong. Its objectives include delineating the resource boundaries and identifying the permeable structures, which could be targets for future drilling. The resistivity structure of Mahanagdong consists of a highly resistive cap (>50 -m), a very conductive middle layer (<10 -m) and a moderately resistive third layer (>10-50 -m). Most production wells were drilled within the moderately resistive layer. The postulated upflow region is characterized by a >40 -m dome-shaped anomaly located beneath the Mahanagdong collapse while the main outflow zone is directed towards the southwest. A still undrilled resource extension of about 6 km2 was delineated farther east of the Mahanagdong collapse. The primary target for drilling towards the east is the Magaas Fault. |