The Philippines' First Geothermal Relief Well

Abstract

Philippine National Oil Company Energy Development Corporation (PNOC-EDC) drilled Well 5R-13D, the first geothermal relief well in the Philippines. Well 5R-13D is probably the only relief well in the geothermal industry drilled using a single shot directional survey system.This well was designed to relieve the pressure of the uncompleted Well 5R-12D that blew out and toppled down the drilling rig on top of it after encountering a shallow pressurized two-phase zone at 450m estimated at about 4 MPa. Early completion of Well 5R-13D was very important to control the environmental, social and economic impact brought about by the continuous discharge. For a time, Well 5R-12D discharge contains part of the re-injected brine from the adjacent re-injection well.
In spite of the various drilling constraints like the proximity of the drilling pad against the main geologic fault prompting a revised welltrack, the non-utilization of MWD tools and time constraints, Well 5R-13D successfully intersected and quenched Well 5R-12D.As an added bonus, the completion test results suggest that this well can even be utilized as a production well. To fully seal off the formerly discharging Well 5R-12D at surface, a series of cement plugs were set through its cut-off casing.