Online Geothermal Well Stimulation and Silica Based Deposit Removal

Abstract

The blocking of reinjection wells by silica based deposits reduces well permeability. This can limit the production of the geothermal power plant and is a major cost to the plant owners to remedy. Conventional well stimulation techniques usually all require the well to be taken out of service and have other disadvantages including significant health & safety risks, high cost of implementation, corrosion and well stressing. An alternative approach where the well does not need to be taken out of service has been developed. The solution combines chemicals and application techniques, derived from understanding how scaling deposits form, and discerning deposition pathways specific to the well, brine chemistry, temperatures, and kinetics. This synthesis facilitates the formulation of tailored treatment chemicals that react with the geothermal silica scale at temperature. Significant and sustained restoration of well permeability has been observed in a number of applications using this new technique and it thus offers the industry an alternative solution that has substantial benefits over traditional approaches.