Polymer Gelants for High Temperature Water Shutoff Applications

Abstract

Abstract Polymer gelants are a well established means for shutting off water in lower temperature formations, but extending their application to hot reservoirs (>80°C) presents a number of technical challenges, particularly in matrix reservoirs. Achieving reliable high temperature performance requires programmable gelation delay, good injectivity, good propagation of gelant components and durability of the permeability reduction. The performance of a gelant against these criteria is dictated by a relatively small set of chemical and physical phenomena. A discussion of these phenomena provides a rational background for assessing the advantages and disadvantages of currently available gelants. This also helps to identify the best avenues for improving polymer gelant systems. This approach is particularly relevant when seeking gelants for high temperature matrix applications, because increased temperature renders it much more difficult to satisfy the four performance features simultaneously.