Imaging Geothermal Resources with 3D Seismic Attributes

Abstract

Seismic reflection surveys are underutilized by the geothermal industry as an exploration tool. New interpretational techniques applied to high quality data demonstrate that useful structural and lithologic data can be obtained, even in complex geologic environments. In this paper, we illustrate the application of seismic data in an exploration program where deep drill holes are available for validation. In this investigation, a set of 3D seismic attributes was extracted from a 3D seismic cube acquired over a geothermal area. The survey covers an area of approximately seven square miles. After processing in the depth domain, a process flow was designed to automatically analyze the attributes over the 3D volume and map the occurrence of anomalous zones using thresholding based on pre-determined values. Tests of the algorithm proved that it was capable of mapping known horizons in a robust manner. Cross-plots of pairs of attributes were calculated and compared with known permeable zones identified from well data.