History of Biliran Geothermal

Exploration and Development History

Biliran Island lies immediately to the north of Leyte, alongside the active Philippines Fault. In 1979-1980, geothermal exploration started in Biliran with the inventory of surface hydrothermal features and geological reconnaissance by PNOC-EDC and KRTA.

• 1979 – 1980 – Geoscientific studies (EDC/KRTA)

Geophysical surveys were conducted between 1980 to 1981 including Schlumberger resistivity traversing (SRT), vertical electrical sounding (VES), and dipole-dipole resistivity survey (DRS). In 1981, DSIR reviewed all surface exploration work done in Biliran as part of New Zealand-Philippines Energy Cooperation Program.

• 1981 –  1982 – Exploration Drilling
  • BN-1 = neutral-CI w/ T = 250°C (low WHP, did not discharge)
  • BN-2 = neutral-C1 w/ T = 210°C (failed to sustain discharge due to mineral scaling)
  • BN-3 = acid CI-SO4, pH 3 at weirbox, T = 330°C (cement plugged due to corrosion)

Based on these studies, three prospective targets were delineated, namely: Vulcan, Kalambis and Panamao areas.
Among these three, Vulcan area was judged most impressive because of its close association with solfataric activiry. In
1982, three exploration wells (BN-1, BN-2, and BN-3) were drilled to test the geothermal potential of Vulcan Area.

• 1991 – 1993 Additional geoscientific  studies (PNOC-EDC)
  • Geology Survey
  • Geochemical sampling
  • Resistivity  (VES)

Figure 1: Different Hydrothermal Systems in Biliran

Figure 2: The Geothermal Model of the Vulcan-Libtong Area

• 2004 DOE looking for investor

• 2007 DOE offers Biliran for bidding

• 2008 Geothermal Service Contract awarded to Biliran Geothermal, Inc. (BGI)

• 2009-20010
  • GRESC
  • Additional Surface Exploration
    • MT Survey
    • Water/Gas resampling
    • Detailed Structural Mapping

• 2013 to present Confirmatory Drilling

Figure 3: Simplified Geological Map of Biliran

Biliran Geothermal Gallery

Photo by Jalmz

REFERENCES

Apuada, N.A. (1992): The Resistivity Signature of Biliran
Island. PNOC-EDC Internal Report. Makati,
Philippines.

KRTA (1986): Evaluation of the Biliran Geothermal
Prospect. PNOC-EDC Internal Report. Makati,
Philippines/

Ramos-Candelaria and Baltasar, A.S.J (1993): Geochemical
and Isotopic Investigation of Biliran Geothermal
Discharges. PNOC-EDC Internal Report. Makati,
Philippines.

Pagado, E.S., Camit, G.R.A and Rosell, J.B (1993): The
Geology and Geothermal Systems of Biliran Island.
PNOC-EDC Internal Report. Makati, Philippines.

Department of Energy (DOE)

Photos by Jalmz