Application of Time-lapse DAS VSP Reservoir Monitoring Technology

Time-lapse borehole seismic is an important technology for reservoir dynamic monitoring. It is more advantageous to use optical fiber for time-lapse VSP data acquisition with high efficiency and high-quality data. Two periods of time-lapse DAS walkaway VSP data acquisition were completed in the eastern China oilfield. High signal-noise ratio, clear reflection of the target layer, and good consistency of VSP were obtained, which met the requirements of reservoir dynamic monitoring. Based on the consistency processing of amplitude and wavelet, wave field separation and other processing techniques, the consistency and efficiency of data processing are improved and the high-precision imaging section is obtained. By comparing the differences of amplitude, frequency attributes and wave impedance of VSP imaging in different periods, the change of oil saturation and other reservoir characteristic parameters with are analyzed.