Project Profile
The Duhat-1 well was designed to reach a total vertical depth of 1,000m. It tested the hydrocarbon potential of the San Isidro anticline, primarily in Miocene Tagnacot Formation limestone and sandstone targets with a pre-drill resource estimate of 1 to 62 million barrels recoverable oil.
During 2012 Otto Energy, on behalf of its Joint Venture partners, acquired 150km of new high quality 2D seismic data over the San Isidro anticline. This anticline has been identified from surface information for sometime but was previously poorly understood and only defined by a sparse (50km) and poor quality seismic. The new data has confirmed a large target, which will be tested by the Duhat-2 well during 2013.
Otto had asked the Philippine Department of Energy (DoE) for permission to conduct a drilling programme in 2013 after confirming the target from seismic data. According to Otto and the DOE, the shoot delineated a sufficient deposit of oil near the town of San Isidro.
Following extensive post-well analysis of the Duhat-2 well drilled in July 2013, however, Otto Energy Investments Limited (OEIL) elected to withdraw from Service Contract 51 (\"SC51\").
Duhat-2 was drilled ahead at approximately 200 metres when the well started to flow high pressure water at high flow rates. Upon analysis, the flow was comprised of brackish water with very low trace gas readings. Standard industry safety practice was followed to shut-in the well using heavy weight mud and, subsequently, a cement plug. OEIL undertook a detailed analysis of the well results (including drill cutting analysis and seismic pressure reviews) to determine if the unexpected Duhat-2 results could be understood.
Based on these reviews, OEIL has concluded a well cannot be safely drilled at the Duhat-2 well location given the shallow overpressures experienced and the indications of low rock strength above the zone of overpressure. In addition, OEIL has formed the view that a well cannot with confidence be drilled in accordance with good industry practice elsewhere on the San Isidro anticline given the results observed at the Duhat-2 location. No other drillable prospects have been identified on existing seismic data available in the northern Service Contract area.
Operators:
Otto Energy: (Rescinded) Operator with 40% working interest in northern block and operator of southern block
SWAN Oil & Gas Ltd: 80% interest in southern block and 40% interest in northern block
Alcorn Gold Resources: 9.32% interest in the northern block and southern block
Trans-Asia Oil and Energy Development: 6.67% interest in the northern block and southern block
PetroEnergy Resources: 4.01% interest in the northern block and southern block