| Abstract |
Well TOl D is fhe twentieth production well drilled in Mindanao Geothermal Production Field (MGPF) and deviated towards the southwestern section of the field primarily to determine the extent of the resource and viability of the thermal fluid in this region for commercial utilization. Well TOl D will be used as one of the production wells supplying steam for the planned 50 MWe geothermal energy expansion project in Mindanao. The well underwent two discharge episodes in December 1994 and November 2004. Based on the discharge testing, well TOl D produces f/urds from two feed zones. The upper feed, characterized as steam, was tapped at a depth of 400 to 200 mRSL while the deeper feed ts at 200 to 100 mRSL. lnitially the deeper zone produced liquid discharge based on the chemistry of the fluid in 1995, but eventually developed into steam in the second discharge test in 2004 due to mass drawdown caused by the fluid extraction from the Sandawa sector. The hottest measuredt emperatureo f the well in 1995w as 260"C (at shut condition) but a much higher temperature of 310'C was obtained in the recent discharge fesf (December, 2004 at bleed condition). The well has an estimated maximum output of 12.4 MWe at a steam rate of 2.06 kg/s-MWe at WHP of 1.69 MPag. The stable discharge enthalpy of the wel is 7 2,600 kJ/kg approximating the enthalpy of the pure steam at 310'C (2727 kJ/kg). Discharge testing of well TOl D proved the existence of high geothermal energy resource (vapor zone) in the southwestern section of the geothermal field and succeeding production wells should be drilled in fhis regian. But the substantial amount of suspended so/ids in steam and high NCG as shown in TOl D discharge should be considered as operational constrainfs in the fluid collection and reinjection sysfem (FCRS/ and power plant desrglnsr,e spectively and mitigating measures to address fhese potential problems should be studied in advance. |