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 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 is a combination of chemicals and application technique based on understanding about the way the deposits are formed, contributing chemistry and deposit pathways specific to sites brine chemistry, temperatures and kinetics. This has facilitated the development of tailored chemicals to react with the geothermal silica based deposits 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.