METHOD FOR PREDICTING SENSITIVITY TO PRESSURE OF SPEED OF SEISMIC WAVES WITHIN THE BREED

摘要

A method for predicting the pressure sensitivity of seismic wave velocity within the reservoir rocks is presented. The method comprises determining the degree of cementation of the rock as at least one of loose sand, partially cemented rock containing the degree of cementation to a level at which the rock is substantially incompressible, and cemented rock containing the degree of cementation at which the rock is, according to creature incompressible. For a rock containing loose sand, the first model was determined that describes the dependence of the speed of seismic waves on pressure. For a rock containing partially cemented rock, a second model is defined that describes the dependence of the speed of seismic waves on pressure, and a weight function that takes into account the degree of cementation of the rock. For the rock containing cemented rock, a third model has been determined, demonstrating the insensitivity of the speed of seismic waves to pressure. In addition, for these moduli of elasticity of dry rock and porosity, the method includes determining the degree of cementation, selecting the appropriate model and using the selected model to predict the sensitivity of the speed of seismic waves to pressure.