A Novel Robust Polymer Gels for Water Shutoff Application in Sandstone Reservoir

Abstract

Polymer gels is an effective method for water shut-off (WSO) application in sandstone oil reservoirs having high water cuts. WSO application can extend the economic life of the field once the undesired water production is minimized. A novel polymer gel was developed for water shut-off applications that extend the limitations of the current available materials for sandstone formation. The new developed system offers chemical bonding of an organically crosslinked polymer gel to the sandstone rock surface, enabling the water shutoff system having enhanced stability with superior performance. The fluid system is low toxic and environmentally acceptable. It is comprised of polymer gel and adsorption components for sandstone formation, In order to enhance the blocking efficiency of WSO polymer gel, specific adsorption component for sandstone formation was introduced into the organically crosslinked polymer (OCP) gel. The gelant can be placed as a single phase, low-viscosity solution into the targeted formation zones. The new Polymer gel Lab rheology study of the new developed polymer gel reveals that both the gelation time and the formed gel strength were greatly affected by the addition of the sandstone adsorption component. By using the appropriate retarder, the gelation time can be controlled without compromising gel strength. The new polymer gel was placed in haigh permeability sandstone core plug, and chase water was subseqyently injected to measure bloking capasity. The core flow test indicates substantial drops in water prduction. The new polymer system was able to withstand 3500 psi differential pressures at 200°F and did not allow the flow of water inside the core sample. The new polymer gel system is expected to control water production through high permeability streaks and large pore openings. The system can be injected in porous media without injectivity reduction due to their low initial viscosity. This work provides significant insight using polymer gel system as an effective chemical treatments intended for carbonate substrate as water shutoff material.