The assumption of constant rate production, which is often invalid for the extended period of production, is one of the fundamental premises for current analytical approaches of temperature transient analysis. This work addressed this issue by introducing novel analytical approaches to model temperature signals under variable rate conditions. The specific methods share underlying theories of superposition principle and production rate normalization from pressure transient analysis. With adapting these methods, cases with complex production history are modelled using analog cases producing with constant rate.
The analytical approach validation is performed by graphically and quantitative estimation of reservoir properties compared with synthetic temperature data. The estimation outputs of these methods include permeability, porosity, drainage area, and damaged zone properties, which are the application combinations from temperature transient analysis and reservoir limits testing. Monitoring well surveillance is extended to variable rate production in this paper. A case documented in the literature is addressed by this temperature analysis for which decent reservoir characterization results are obtained. The temperature analysis proposed in this paper extends the scope of temperature transient analysis to complex production constraints and demonstrates convincing results for practical purposes.