In-Depth Reservoir Placement of pH-Sensitive Polymer Gels - Importance of Geochemical Reactions in Numerical Simulations
A. Jahanbani Ghahfarokhi, J. Kleppe and O. Torsaeter
Event name: 80th EAGE Conference and Exhibition 2018
Session: Chemical EOR II
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 469.1Kb )
Price: € 20
To improve the sweep efficiency in fields characterized by high water cut after production by water flooding, conformance control is required. This involves application of water diversion by gels to block the high permeability zones. In-depth gel placement is a challenge since gelation time is usually too short for the gel to penetrate deep into the reservoir. A method proposed to model delayed gelation is to use pH-sensitive polymers that exhibit large viscosity increase when pH exceeds a critical value. Numerical simulation is performed in this study to investigate the application of pH-sensitive polymer in porous media. Several minerals are included in the simulation study and effect of geochemical reactions on gel placement is investigated. Results suggest that pH-sensitive polymer gels may improve the recovery factor significantly when applied as slug in reservoirs with negligible crossflow between layers. Different injection scenarios were evaluated. Improved results are obtained if water injection into the high permeability layer is shut-in after the polymer injection so that the gel can form in place. Mineralogy and reaction kinetics are among the most important parameters to be considered for the design of pH-sensitive polymer gel injection.