Application of Nonparametric Regression on Well Histories at Mahiao and Mahanagdong Sector of Leyte Geothermal Production Field, Philippines

Abstract

Investigation on the applicability of the nonparametric regression ACE (Alternating Conditional Expectation) method was extended to different sectors of Leyte Geothermal Production field of Energy Development Corporation (EDC) in the Philippines. The method correlated chloride concentration history of production wells with brine injection rates to predict well-to-well connections which is useful in designing a strategy for brine injection, and determining where thermal breakthroughs are likely to occur. Good chloride history matches were obtained for some wells but well-to-well connection indices have some inconsistencies compared with tracer test data. The method was initially applied in Palinpinon-1 sector of Southern Negros Geothermal Production Field (SNGPF) and yielded good results. The derived equations were also validated to two other fields namely, Mindanao Geothermal Production Field (MGPF) and Palinpinon-2 which was likewise in SNGPF. Results, however, showed that the approach was greatly affected by prevailing field extraction.