Time-lapse Seismic Analysis Using Reservoir Geomechanics Model

Time-lapse seismic technique can help us understand the dynamic properties of hydrocarbon reservoirs in three-dimensional space over time.At present,it is increasingly difficult to find conventional hydrocarbon reservoirs.Therefore,how to develop the remaining oil and gas reliably and efficiently has become an urgent task for oil companies.According to some studies,reservoirs that are ideal for time-lapse seismic monitoring are required to meet the three following criteria:(1)large reservoir pressure depletion,(2)reservoir units having large thickness,and(3)poorly consolidated and compressible reservoir units with high porosity.However,there is still a lot of uncertainty in the study of how the production induced rock distortion and fluid property change affect the time-lapse seismic wave field.In view of this,based on the numerical simulation of reservoir geomechanical model and the physical model of fluid substitution,we use seismic numerical simulation and physical simulation to explore the sensitivity of seismic waves to dynamic change of reservoir property.In addition,we use time-lapse seismic acquisition and processing methods to obtain time-lapse seismic attributes,and quantitatively or qualitatively explain them,and explore the effect of fluid change on time-lapse seismic wave field.It is found that there is a good consistency between seismic forward modeling and real geological model.Meanwhile,the influence of pore fluid change on the experimental data of reservoir physical model is obvious.Time-lapse Q and wave impedance difference can reflect the change of reservoir fluid.Therefore,this method can help us analyze the error and uncertainty in time-lapse seismic analysis.