A Study On Estimating Clay Content And Porosity Of Reservoir Based On Seismic Information

Methods of exploration geophysics play an important role in gashydrate prospecting and development. Not only in the field of gas hydratevolume estimation, but also in careful description of reservoir and inthe field of well position confirmation, the corresponding geophysicaldetecting technique should be developed. Seismic exploration play a veryimportant part in the existing methods of geophysical prospecting.In the field of gas hydrate and free gas' saturation estimation, howto describe the characteristics of gas hydrate reservoir using seismicprospecting method has become an important assignment which currentgeophysicists reinforce.This paper begins at three-phase Rock physics model(the modelconsidered the effect of rock frame, fluid, Clay content, Porosity andhydrocarbon saturation upon P-wave velocity(Vp) enough). Forward modeldemonstrates the relationship between the parameters (Porosity, Claycontent, Saturation) of reservoir and seismic wave velocities (Vp,Vs).The law between Seismic wave velocity (P-wave velocity is most important)and Porosity, Clay content and Saturation could be disclosed.Inversion plan is confirmed on the base of analyzing the result ofForward model. There are two different methods of inversion. One is calledempirical formula method;the other is single parameter inversion method.In the process of inversion, we associate practical seismic data with 995Bwell data at Blake Ridge which locates in the southeast continental marginof the USA.The inversion results indicate that the clay content valuescalculated by the two methods mentioned above have little errors. Porosityvalues calculated by the methods are identical with 995B well data.