Experimental study of temperature effects on wellbore material properties to enhance temperature profile modeling for production wells

Abstract

In a wellbore, transient pressure and temperature behavior occurs as hot reservoir fluids flow upwards and exchange heat with the surroundings. This type of heat transfer happens in drilling, production and injection operations. Wellbore components such as tubings, cement sheets, casings and fluids play a major role in the heat exchange. To estimate and quantify the transferred heat, knowledge on the thermophysical parameters of the wellbore components is essential. This information is important to consider during the planning phase to find the optimal combination of materials used in the well construction to achieve top safety at lowest costs. In this study, experiments were performed using a C-Therm TCi™ thermal conductivity analyzer to measure thermophysical parameters of typical wellbore components (fluids, casings, tubings, cement sheets and formations), specifically, thermal conductivity. The results of the experiments were used to derive temperature-dependent thermophysical correlations, which were applied in a wellbore heat transfer model for oil production scenario by considering a complex well architecture. In simulations, parameter sensitivity tests reveal that as the flow rate of the produced fluid increases, the rate of heat loss of the fluid decreases, and the rate of fluid temperature drop becomes lower as the production time increases. Comparison of simulations’ results for four cementitious materials show that fly ash-based geopolymer has better thermal resistance than other tested materials (Neat class G cement, slag-based- and rock-based geopolymers). When the produced fluid was changed from crude oil to water, it experienced less heat loss from the bottom to the surface. The results of this study provide an idea about thermal behavior of various well components and can be useful for the material selection for geothermal, production and injection wells design.