Methods of Coping with Silica Deposition -The PNOC Experience

Abstract

Several methods of coping with silica deposition from geothermal waters have been undertaken by PNOC-EDC to maximize power output from these fluids. Initially, the problem of amorphous s 5 c a deposition in surface pipelines and the reinjection wells was prevented by operating the production separators at pressures higher or equal to amorphous silica saturation. However, increasing demands for additional power and stringent environmental controls have dictated the need to find alternative methods of coping with silica deposition. Several options have been studied and tested to be able to utilize fluids for production. These include: acid treatment, polymerization and deposition of silica in surface ponds or sumps and chemical dubitation. As each brine is unique, methodologies used for mitigation of the silica problem have been varied.