SEGJ Technical Conference

Repeatability estimation of time-lapse study by ACROSS methodology using a conventional seismic source

Abstract . In order to do the time-lapse studies for EOR, CCS and monitoring of subsidence and landslides, we propose to use the ACROSS (Accurately Controlled and Routinely Operated Signal System) technology. Due to the difficulty of using ACROSS seismic source, we actually used the conventional seismic source for the exploration seismic survey with implementation of ACROSS methodology. To discuss the real temporal change in subsurface, we evaluate the normalized root mean square (NRMS) repeatability. The field data were obtained at a former quarry site. In comparison of 1-week data in July and August, 2014, the typical repeatability of first arrival shows > 3%. The data further than 300 m show better repeatability. The repeatability of the measurement system could be < 3% and the near-surface layer might degrade the repeatability by rainfall and outside temperature effects.