Prediction of the temperature distribution in the reservoir when oil is displaced by a fluid with a temperature different from the reservoir

Abstract

The temperature field is an important factor that must be considered when using thermal methods to intensify oil production. The change in the temperature field is accompanied by a change in the thermophysical properties of reservoir fluids and the entire bottom-hole zone. For example, changes in fluid viscosity, phase transformations or paraffin deposition. The prediction of the thermal field in the reservoir during fluid injection with a temperature other than the reservoir is an important and actual task. All the processes described above are based on the prediction of the temperature field and its evolution. Non-isothermal filtration models embedded in expensive commercial simulators are used to analyze the thermal field in formations, which allow calculating its detailed evolution in geologically complex deposits. However, many tasks are reduced to determining the probability of activation of a particular thermal process in the reservoir. Therefore, the purpose of this work is to develop a simplified model of the evolution of the thermal field in the reservoir during fluid injection with a temperature different from the reservoir. In this paper, the stationary problem of the distribution of fluid temperature in the injection well trunk is solved. An algorithm for determining the heat transfer coefficient by measuring the temperature at the bottom of the well has been developed. A simplified model of the formation of a temperature field in a reservoir during the injection of a fluid with a temperature different from the reservoir in the Lauwerier approximation is formulated. The formula for determining the average value of the heat transfer coefficient along the entire length of the formation is obtained. It is shown that the heat transfer coefficient depends on the thermophysical properties of the injected fluid and the parameters of the injection well operation. It is shown that the absence of measurements of the thermophysical properties of rocks and reservoir fluids leads to predictions of the thermal field with maximum uncertainty in the half of the impact site closest to the injection well.