ON MEASURING AND INTERPRETATIVE METHOD OF PERMEABILITY AND POROSITY OF TIGHT ROCKS

It is essential to determine the physical property parameters (for instance, permeability and porosity) of reservoir rock in exploring and developing oil or gas field. Because of the low flow rate, the normal core analysis is helpless to determine permeability of samples such as tight gas sands, limestones and shales. In this paper, an optimization model is established to calculate permeability and porosity of a core sample by means of auto-matching the pressure vs. time behavior observed at the end of the jacketed sample while a pore pressure pulse is applied to another. The numerical method of solving the optimization model and the mathematic model that describes fluid unsteady flow through porous medium are presented. The practicality and reliability of the measuring and interpretative method are verified in an example.