New approach for improved history matching while incorporating wettability variations in a sandstone reservoir—Field implementation

• Capillary pressure correlation for accounting for wettability variations.
• Methodology to incorporate such variations later into relative permeability curves. Its mathematical solution.
• Real field case study situated in Malaysia by adopting the developed technique for improved history matching.
• Successful/improved history matching by using the developed methodology.

Wettability plays an influential role in fluid distribution and flow behavior within a reservoir, due to its strong influence on capillary pressure and relative permeability. Because of its significance, it plays an important part in history matching and simulation studies. But, despite its importance and crucial role, it is usually not accorded significant attention during simulation studies. Different types of wettability may exist or co-exist within a reservoir which may alter while drilling due to invasion of mud filtrate in near wellbore area or with the passage of time due to various undergoing processes under prevailing conditions. In order to account for the effect of such wettability variations on fluid flow behavior, a set of correlations developed by us has been used in this study, to predict capillary pressure curve under any prevailing wettability conditions, when the laboratory data from the core at any known wettability condition are available. Sequentially, the methodology has been formulated, to incorporate wettability variations effects in experimental relative permeability data. The developed methodologies for including wettability alteration effect into flow affecting parameters have been implemented on Malaysian oil reservoir for improved history matching. The obtained results show better history match with the field data, thus verifying the significance of the designed approach.