| Title | Well Stimulation Techniques Applied at the Salak Geothermal Field |
|---|---|
| Authors | Riza G. Pasikki, Frederick Libert, Keita Yoshioka, Reggie Leonard |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Salak Geothermal Field, Thermal Fracturing, Slow Acidizing, Coiled tubing acidizing, hydraulic stimulation |
| Abstract | The Salak field is the largest developed geothermal resource in Indonesia operated by Chevron. Steam production levels in Salak have been successfully maintained at or above the rated power plant capacity since 1994. Infill drilling has been the primary tool to meet the steam supply target. Besides formulating steam supply strategy, formulating injection strategy is also a key parameter for field management in a liquid dominated geothermal resource like Salak. It is recognized that Salak reservoir performance would be improved through moving injection from current, infield locations, to outfield locations. During the most recent drilling campaign, several delineation wells have been drilled outside of the proven reservoir boundary to replace existing injectors. Drilling delineation and new infill wells in a naturally fractured volcanic reservoir with varying mineralogy over wide temperature range has always been challenging. A number of newly drilled wells have low permeability which limits their production or injection capacity. The low permeability could be either induced by damage which occurred while drilling or due to inherent features. Several stimulation techniques such as massive water injection, thermally-induced, slow-acidizing, and coiled-tubing acidizing have been applied to enhance permeability of these sub-commercial wells with various degrees of success. Application of these stimulation techniques has replaced the old practice of redrilling or side-tracking new wells with low permeability. This paper describes the designs, processes, and outcomes of applied stimulation techniques as well as techniques to interpret surveillance data collected during stimulation. |