The interpretation of natural fractures is the utmost importance for identifying flow zones in geothermal reservoir characterization. The high-resolution resistivity borehole image log can resolve reservoir fracture and sedimentary features down to 0.2-in.However, it reflects wellbore surface information due to its shallow depth of investigation. In order to further identify a fracture’s openness and effectiveness beyond the wellbore for geothermal production, the borehole sonic log can provide supplemental fracture information, by analyzing the reflection of the Stoneley wave that propagates away inside the formation. Moreover, geomechanical analysis can provide fracture stability information. By combining fracture analysis results from the borehole geology, acoustic, geomechanics, and other available data, the true flow zones can be readily identified as a feed point, which is crucial for further reservoir development. In this paper, we discuss the workflow of an integrated fracture analysis from a single well using multidisciplinary wellbore data, and introduce a case study from a volcanic geothermal well in Japan.

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