Rock Physics Modeling in Sandstone Reservoirs – Review of Theoretical Models and a Field Example

In this paper, we begin with a discussion on the relations between seismic velocity and porosity in clastic reservoirs. We then provide a brief overview of the theoretical background for some important rock physics models in granular media, including friable-sand model, contact-cement model and constant-cement model. We then present an example of application of rock physics modeling to a well log and core dataset extracted from a real case study. Based on a rock physics diagnostic technique, it is possible to quantify different diagenetic and sedimentologic factors in terms of rock physical properties. In this study, on a real dataset, this is carried out by adjusting the curve of a rock physics theoretical model (constant-cement model) to a trend in the velocity–porosity dataset, and then interpreting the rock physics/microstructure as that used in the theoretical model. This model is then used to make prediction of seismic velocities. The results of this study can be used to interpret the seismic data quantitatively and update the reservoir property models.