A comprehensive review of in-situ polymer gel simulation for conformance control

Gel treatment has been widely applied in mature oilfields to improve sweep efficiency and control water production. Correct numerical simulation is of major importance to the optimization design and prediction of a successful gel treatment. However, there exist many problems in current simulation studies in published literature. This paper first presents a comprehensive review on the major factors that have been considered at different gelation stages during gel treatment, the models used in the commercial/in-house simulators, and current numerical simulation studies on both laboratory and field scales. Then we classify the current in-situ gel numerical simulation problems as 1, deficient model problem that has published numerical model but has not been applied in simulator and application studies; 2, missing model problem that does not have published quantitative model; and 3, inaccurate application problem that does not consider the major factors of gel performance, based on the reasons from some questionable results of current simulation studies. Finally, we point out the major research efforts that should be made in the future to better simulate in-situ gel treatment process. The review indicates that numerous simulation studies using commercial software packages intend to predigest the gel treatment, many of which, however, ignore important mechanisms and mislead the operation of gel treatment. In fact, a full assessment of simulating in-situ gels cannot be achieved unless the quantitative models can be qualified in terms of transport and plugging mechanisms based on the experimental results.