Establishment of Models for Tight Sandstone Formation Evaluation in the Ordos Basin of Northwest China

Porosity and permeability are two important input parameters in formation evaluation. However, It faces a great challenge for formation porosity and permeability estimation in tight sandstone reservoirs in the Ordos basin of northwest China due to the greater contribution of rock matrix and complicated pore structure. In this paper, based on the analysis of conventional log responses and 324 core samples drilled from the target formations in different wells, the estimation models of reservoir porosity and permeability are established, and the reliability of these models are verified by comparing the calculated porosity and permeability by using the established models with core analyzed results. The absolute errors between these two kinds of porosities are all lower than 0.64%, and the relative errors between them are lower than 7.1%, these are coincided with the requirement of reserve estimation.