Surface time-lapse multi-component seismology – a new technology for hydraulic fracture monitoring? A Montney Shale gas case study
Several technologies have been traditionally used to monitor hydraulic fractures. Microseismic methods and the use of tiltmeters have provided satisfactory results. These methods estimate the vertical location of the failure events due to the stimulations with adequate accuracy. This study aims to evaluate the value that 4D surface seismic can add as a complementary method for hydraulic fracturing monitoring. Seen initially as a purely qualitative tool, its effectiveness as a powerful quantitative technique is being established among the scientific community. The present work provides evidence that time-lapse multi-component seismic data can monitor the hydraulic stimulations of two horizontal wells in the Montney Shale. The methodology focuses on the detection of time-lapse time shifts using both compressional and mode-converted wave data. The results prove the detectability of the changes in the stress field using this technique. Changes are observed not only within the reservoir but also in the overburden and the variations above the reservoir constitute the main focus of the interpretation. Results suggest that 4D seismic can be of great help in building accurate models of the reservoirs and their surroundings, which in turn will allow for prediction of the stimulation performance and optimization of recovery.