Estimation of Water Saturation in Rocks with Conductive Matrix

Abstract

The purposes of this study are to develop a water saturation model (MCRM model) for a formation with conductive rock matrix and to calculate the empirical parameters used in the model by using the optimization method. The empirical parameters in the new model (MCRM model) include the conductive formation parameter (b′), tortuosity factor (a), cementation exponent (m), and saturation exponent (n). A field data is used to illustrate the procedures to derive the empirical parameters by the optimization method. The results of the empirical parameters from three models, the MCRM model, the Givens model, and the Archie equation (model), are compared. The conductive formation parameter (b′) for the field data analyzed is less then one, indicating that the formation contains conductive rock matrix.

Keywords:

• Archie parameters
• conductive rock matrix
• optimization

Acknowledgments

The authors give special thanks to Yi-Yi Lin, a graduate student from the Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan, for programming the optimization process in MATLAB used in this study.

Notes

^a Obj. = the value of the objective function.

^a The effect of the tortuosity factor is not considered in the Givens model.

^a The effect of the formation conductivity is not considered in the Archie equation.