抄録
In the optimization process of water injection into a vapor-dominated geothermal reservoir for resource recovery, it is required to quantitatively evaluate vaporization behavior of the injected water in the reservoir and responses of production wells to the water injection.
In this study, six runs of tracer tests were conducted at four wells in the Matsukawa vapor-dominated geothermal field. Two-phase tracers (lower alcohols; methanol, ethanol, 1-propanol, and 2-propanol) were used in the tests because moderate vapor saturation zone was likely present in the Matsukawa reservoir. The tests revealed hydraulic connectivities between injection and production wells, and physical characteristics of injected water flow. The test results implied distribution of permeable fractures and identified responses of production wells to the water injection. Furthermore, production interference among production wells was successfully predicted from a tracer test prior to the beginning of steam production from a newly drilled well.
