| Title | Geothermal Reservoir Imaging Using 2016 Walkaway VSP Data from the Raft River Geothermal Field |
|---|---|
| Authors | Benxin CHI and Lianjie HUANG |
| Year | 2019 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Raft River geothermal field, vertical seismic profile, seismic imaging, elastic-waveform inversion, elastic reverse-time migration |
| Abstract | The Raft River geothermal field was selected by the U.S. Department of Energy (DOE) as an Enhanced Geothermal System (EGS) demonstration project in 2010. Reliable geothermal reservoir characterization requires high-resolution subsurface imaging. A vertical seismic profile (VSP) survey was conducted along five walkaway lines in 2016. We build a 3D velocity model using 3D elastic-waveform inversion of the five walkaway VSP data. The 3D velocity model reveals a low velocity zone, which may be associated with the Narrows zone, a fractured zone for EGS stimulation. We then apply 3D least-squares elastic reverse-time migration to the five walkaway VSP data and obtain a high-resolution subsurface image, showing detailed subsurface structures surround the Narrows zone. Our results demonstrate that 3D elastic-waveform inversion and 3D least-squares elastic reverse-time migration of walkaway VSP data can produce useful subsurface information for geothermal reservoir imaging and characterization. |