Combined analysis with field production history and DST data on vertical permeability and fault conductivity

Abstract

This paper introduces a reservoir study for a gas field which have problems of complicated water production behavior. In order to understand the mechanism of the water production, a simple sector model was constructed to reproduce the production history and well test analysis result.

Taking the geological information into consideration, water production mechanism of this field was assumed in two patterns: in lower formation, gas water contact level has been risen and in upper formation, water moves from the lower aquifer zone through conductive faults.

In lower layer, vertical to horizontal permeability ratio and aquifer volume are important parameters which have major effects on water production behavior in the simulation study. The ranges of these parameters were narrowed by the history matching process for reproducing pressure transient analysis and water production using simple sector models.

In upper layer, authors assumed water goes through conductive faults. For reproducing this phenomena, pseudo-relative permeability curves were employed. By history matching process using simple sector model which was implemented this pseudo-relative permeability curve, the range of distance from conductive fault to the well was also estimated.

By this study, the complicated water production mechanisms were understood then the uncertainties of some important reservoir parameters were reduced. These information and knowledge can be strong support for full field simulation model study.