| Title | Silica Deposition in Near-Wellbore Formation: Study on Mechanism and Management Options Based on Autoclave Experiments |
|---|---|
| Authors | Farrell SIEGA, Bruce MOUNTAIN, Ian RICHARDSON and Aimee CALIBUGAN |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | silica scaling, formation, autoclave experiment |
| Abstract | Managing silica scaling in plant surface facilities, injection wells and near-wellbore formation can be a major challenge in geothermal field operations. Determining which management option is appropriate depends on the overall understanding of the mechanism of silica deposition both at the surface and within the reservoir formation. Factors driving silica deposition in plant facilities and injection wellbores seem to be well understood hence effective control of scaling have been implemented by several geothermal plant operators, such as the use of pH-modification technology. The mechanism of silica deposition in near-wellbore formation of an injection well however is not as well understood. A series of autoclave experiments were conducted to study near-wellbore formation silica scaling. These experiments were mostly designed to investigate water-rock interaction of acid-dosed brine in greywacke formation and its influence on silica deposition. These tests have been used to understand things such as the effects of adding chemical inhibitor and filtrate injection from silica extraction plant. This paper will discuss the autoclave testing methodology and how the results of the study provide better understanding of the mechanism of silica deposition in the reservoir formation, including how the autoclave testing can be used to assist with pre/post-development risk mitigation. |