Abstract
Productions from oil and gas reservoirs can induce significant pressure and temperature changes at the wellbore. The temperature signal is sensitive to reservoir properties and production parameters which can be very useful in characterizing the reservoir. In this work, we introduce novel analytical solutions to determine the temperature signal associated with theproduction of slightly-compressible hydrocarbon from a vertical well, and apply the solutions to the production from oil and gas reservoirs. Our procedures to obtain the analytical solutions from the governing equation involve making relevant assumptions that allow rigorous solutions to be constructed using Laplace transform. We extend the analytical solutions to include the near-wellbore damage, and to characterize the damaged zone.
Our results of the analytical models are benchmarked with those from a commercial numerical simulation software. We substantiate that the Joule-Thomson effect on the temperature profile is significant in near-wellbore region, and adiabatic expansion effect extends the radius of investigation of the transient temperature signal. The damaged zoneanalytical solution shows that damaged zone radius and permeability separately affect thetemperature transient signal. This isunlike the pressure transient response for which the effect of damage zone properties is lumped into a single parameter, i.e. the skin factor. The analytically derived equations for slopes of Joule-Thomson and adiabatic expansion effects in undamaged and damaged reservoir present very close agreement with those obtained numerically. We provide semi-log temperature interpretation techniques to determine the reservoir permeability and porosity, and damaged zone radius and permeability.
