Evaluation of Hydraulic Stimulation-Induced Permeability Enhancement

Abstract

With permeability playing a major role in defining a geothermal well’s production and injection capacity, a recently-drilled well in the Philippines, found to have low permeability during its post-drilling completion, was subjected to a five-day hydraulic stimulation. Completion test after the stimulation was consequently conducted to quantify any permeability improvement that could be attributed to the procedure. The completion tests done in the well include moving pressure-temperature-spinner logs, injectivity, and pressure fall-off tests. Wellhead pressure was also monitored throughout the tests and during stimulation. Continuously declining WHP throughout the duration of the tests - from very high positive values to vacuum, increase in injectivity index and permeability-thickness, and additional permeable zones inferred by the moving logs suggest the success of the stimulation activity.