Petrophysical Measurements for Time-Lapse Seismic Monitoring of Reservoir Waterflood Recovery

Abstract

Petrophysical measurements are the basis of time-lapse seismic monitoring of reservoir waterflood recovery. By modeling reservoir condition as well as performance of water injection and gas injection, petrophysical elastic measurements are carried out on five samples from the Shengli oilfield in laboratory. The focus is to analyze the influence of pore fluid substitution and temperature and pore pressure on compressional and shear wave velocities. The experiments show that variations of compressional and shear wave velocities of rock caused by pore fluid substitution and temperature as well as pore pressure are very small in the condition of water injection, implying large risk for time-lapse seismic monitoring. In comparison, gas injection can produce clear changes of compressional wave velocities, which helps carry out time-lapse seismic monitoring. Improving experimental methods and enriching experimental contents are the major tasks of petrophysical measurement for time-lapse seismic monitoring in the future.