Utilization Potential of Marginal Well to Maintain Steam Supply to Geothermal Power Plants: Case Study of Lahendong Field, Indonesia

Abstract

Problems in Lahendong geothermal fields are related to the decline in steam supply from existing production wells. This can be caused by various factors, including reservoir pressure decline or damage to production wells. On the other hand, there are several marginal wells in the Lahendong prospect and Tompaso prospect. This research focuses on the Tompaso prospect, although steam availability is still sufficient to meet the commitment of 40 MW generation, we must prepare a steam buffer to avoid steam shortages which cause a loss of revenue. The LHD-B well, a marginal well in the Tompaso prospect, has a temperature of 284°C and exhibits potential permeability, as indicated by total loss circulation during drilling. The stimulation equipment available was limited at that time so the discharge effort was not continued. Optimizing LHD-B wells lies in addressing the challenge of declining production without the need for costly and time-consuming new drilling. The method used in this study includes a comprehensive evaluation of the inactive well conditions, reservoir performance analysis, and the application of stimulation techniques. After well repairs were carried out to restore well integrity, wellbore simulations were conducted to determine the potential steam production capacity. The results of this study indicate that the LHD-B well has the potential to increase steam supply and maintain the stability of the operation of PLTP Units 5 & 6, thus potentially delaying the need for new well drilling