A NEW POWERFUL TOOL FOR INTERPRETING AND PREDICTING IN RESERVOIR GEOPHYSICS: THEORETICAL MODELING AS APPLIED TO LABORATORY MEASUREMENTS OF THERMAL PROPERTIES

摘要

This paper demonstrates new possibilities provided by a combination of effective medium theory (EMT) with laboratory experiment on thermal properties of porouscracked rocks. Such a combination can solve many actual problems in petrophysics and prospecting geophysics including EMT-based inversion of pore/crack geometry and thermal conductivity (TC) of mineral matrix from TC measurements on samples saturated with different fluids. The inverted geometry is used for EMT-based prediction of the other physical properties (elastic wave velocities and coefficient of linear thermal expansion). The opposite procedure is also applied — TC prediction from measurements of elastic wave velocities and electrical resistivity. An example is presented of reconstructing the TC distribution along a well from sonic, density, and porosity logs. The theoretical modeling is shown to be a useful tool in solving the ‘oil-in-place’ problem from measurements on density, volumetric heat capacity, and porosity. The EMT is used to reconstruct the distribution functions of pore/crack volume over aspect ratio before and after experiment at elevated pressure and temperature (PT) conditions and reveal principal factors controlling the TC change at these conditions.