Performance Evaluation of Polymer Gel Composite Resin Coated Sand Water Shutoff System

Abstract

Aiming at the problems of low plugging strength and short plugging time of Polymer gel in fractured ultra-low permeability reservoirs, a composite plugging process of Polymer gel and resin coated sand is proposed. This paper evaluates the rheological properties of Polymer gel and the consolidation performance of resin coated sand through laboratory tests. Furthermore, the sand-packed tube was used to compare and evaluate the water blocking ability of Polymer gel and resin coated sand alone and the combined water blocking ability of the two. The results show that the initial viscosity of Polymer gel is very low (20-30cp), the strength after gelation is high (>40000cp), it has certain temperature and salt resistance, and it can still maintain high gel strength after shearing. However, after long-term water flooding, its plugging strength gradually decreases, and its plugging validity period is shorter. The selected resin coated sand has better consolidation effect at reservoir temperature and good plugging ability. After combining the polymer gel with the selected resin coated sand, the plugging strength and validity period of the system have been greatly improved. The research results in this paper can provide new exploration ideas for chemical water shutoff in fractured ultra-low permeability reservoirs.