Reservoir Permeability Assessment of the Mindanao Geothermal Field, Philippines

Winston Philip C. Pioquinto

PNOC Energy Development Corporation,
Merritt Road, Fort Bonifacio, Metro Manila 1201, Philippines

 

The distribution of reservoir permeability in the Mindanao geothermal field varies generally for each sector (Matingao, Marbel and Sandawa). Steam bearing fractures are either low-angled or high angled with a random to semi-random orientation. The low angled fractures may be confined to specific strata bounded by steep high-angled fractures which are represented by faults mapped in the surface. Most dominant strike of such sub-vertical to vertical faults trend NW (Marbel Corridor) and NNE in the Marbel-Sandawa interface. A lithologic break between the Upper sequence and Lower sequence of the Apo Volcanics defined by a claystone horizon also contributed to a fieldwide permeability.