| Title | Tracing of Injection by Using Gases Derived from Lost-Circulation Materials in Matsukawa Geothermal Field, Japan |
|---|---|
| Authors | Daisuke Fukuda and Masahiro Sarudate |
| Year | 2008 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Tracer, lost-circulation material, two-phase reservoir |
| Abstract | Tracer testing using alcohols were conducted in the Matsukawa vapor-dominated reservoir since 2000 (Fukuda et al., 2005). In addition to the alcohols, two unexpected gases were detected by gas chromatography during the test conducted on well M-14 prior to the completion of the drilling. We concluded that the gases were derived from lost-circulation materials (LCMs) used for the drilling of well M-14, which was confirmed by heating experiments of the LCMs in the laboratory. The LCMs were products of cottonseed hull and pulp. The LCM-derived gases were found in all the monitoring wells in the Matsukawa vapor-dominated reservoir, although the alcohol tracer was detected in the only two production wells. The return curves and arrival times were obtained by the monitoring of the LCM-derived gases and they showed that the fluid flowed from the southwest to the northeast within the system; this flow direction is consistent with the previous study of the pressure distribution (Hanano and Matsuo, 1990). With the results obtained during the monitoring, we concluded that the LCM-derived gases can be used as a tracer to detect the breakthrough of the drilling fluid in the vapor-dominated reservoir. |