| Title | Evaluation of the Results of the Tongonan-1 CO2 Injection Project |
|---|---|
| Authors | Romeo G. Jabonillo, Edwin H. Alcober, Joselito P. Villena, Danilo H. Cruz, Jose Rufino S. Pe±aranda, Dennis R. Sanchez, and Herman V. Guillen |
| Year | 2003 |
| Conference | PNOC-EDC Geothermal Conference |
| Keywords | |
| Abstract | The Tongonan-1 CO2 Injection Project aims to reduce gas emissions from geothermal power station by injecting the gases to the reservoir through mixing with Tongonan brine. Silica deposition could also be inhibited due to lowering of the brine pH after gas mixing. The brine has a pH of 6.1-6.2 and SSI of 1.10. Injection of 0.36-0.60 TPH NCG resulted in brine pH decline to 5.2-5.6, with notable increase in dissolved gases of 20 ppm CO2 and 5.5 ppm H2S. Inspection of the test spools showed that deposition of amorphous silica, calcite and anhydrite in the gas treated line was insignificant. UT gauging in the injection set-up showed that thinning was insignificant indicating that corrosion was minimal. Although the tests showed feasibility of injecting gases to the reservoir and modifying brine pH to minimize silica polymerization, the amount of gas injected was low (0.60 TPH), or only 16% of the amount of waste gases (3.78 TPH) available from Unit #3. Also, the brine requirement (598 TPH) to dissolve the injected gases was high, making it difficult to operate the system. These concerns will limit the feasibility of CO2 Injection in industrial applications, especially in fields with limited amount of brine. |