The seismic data acquisition capability of Distributed Acoustic Sensing (DAS) fiber optic systems provides revolutionary new opportunities for borehole reflection seismology to contribute to reservoir engineering solutions. Sterling Seismic & Reservoir Services has developed unique new seismic data processing technology that utilizes modern DAS data recorded on the horizontal leg of oil and gas wells to quickly generate seismic image results. The resulting seismic images can be used, along with rock mechanics analysis, to measure time-lapse changes in reservoir properties such as seismic velocity, pore pressure, rock stress, stress direction, and fracture density.
Time Lapse DAS Reflection Imaging for Reservoir Engineering
The reflection image above was generated using DAS data recorded on only the horizontal part of the borehole which was at a depth of about 9,000 ft. The red line at the top of the seismic section shows the location of the borehole and the DAS cable. The maximum Vibroseis sweep frequency was 120 Hz and the maximum usable frequency of the image is 105-110 Hz. The image trace spacing is 6.66 ft which gives outstanding horizontal resolution compared to surface seismic data.
Videos from our Sterling Tech Talks give many more details and real data examples of using time-lapse DAS data for reservoir analysis purposes.