Service Contract No. 37 – Cagayan

Project Location : Cagayan Basin

JV Partners and Percent Equity :  None

Project Description: SC 37 was awarded by the Department of Energy (DOE) to PNOC EC on 18 July 1990, originally covering an area of 2,200 sq. km. In 1997, it entered into a twenty-five (25) year production period when the San Antonio Gas Field was declared commercial by the DOE. This required PNOC EC to relinquish portions of the block retaining only the production area. Presently, SC 37 covers only 360 sq. km.

Brief Background : PNOC EC’s exploration activities in the Cagayan Basin started in 1974 and the 1st well, Rizal 2, was drilled in 1975.  Although gas was present, it was not tested because oil was the objective of the drilling.  In 1981, San Antonio 1 was drilled and flowed gas – PNOC EC’s first discovery.  It was a modest discovery but at the time it was not feasible to produce.  When new developments in gas-fired power plants were available, producing small gas fields like San Antonio became viable.

In 1995, the San Antonio Gas Field started production supplying the fuel requirements of a 3-MW power plant.  The field was in production until 2008 and by the time it was depleted it produced 3.54 BCF of gas.

During the production period of San Antonio, PNOC EC re-assessed the petroleum potential of the area, including the old Rizal 2 well, which had gas. One of the prospects identified was Mangosteen.  The well was drilled in March 2015 and several gas-charged zones were encountered and tested. The Mangosteen-1 Well was considered a Gas Discovery Well as confirmed by the DOE.  Presently, PNOC EC is conducting post-well evaluation and assessment of the block for possible appraisal drilling.


As of end Dec 2016

(page update February 8, 2017)