Fluid Phase Prediction Using Temperature Transient Analysis During Formation Testing

Abstract Saturation calculation comes with challenges usually related to and not limited to geological complexity. Moreover, fractional flow presents a unique challenge where influence of relative permeability within a lithofacies will result in different fractional flows from the same saturation. This project uses thermal transient data modelling to solve from flowing phases independent from the above challenges. Using formation testing pre-tests as a source of thermal input during the draw down, a drop in temperature occurs due to the Joule-Thompson effect resulting in a temperature build-up as the system tries to get back into equilibrium. Using this data from previously drilled wells in the same or similar geological setting allows for generation of calibration type curves that provide insight into the behavior of the reservoir in cases of different fluids flowing and in cases of fractional flow. These type curves can be then applied to all acquired pressure points in new wells which can be used for completion and well analysis purposes. The method was applied to both clastic and carbonate reservoirs with promising results where it was possible to determine the mobile phases without using resistivity, NMR or acquiring samples. Moreover, the method made it possible to determine fractional flow without using relative permeability as input and without describing the different lithofacies. Type curves overall showed good repeatability against fluid samples and flow after completion where the determined phase matched with the final results. Method is generally capable of determining the major saturating mobile phase as long as the signature is not masked by interference from extremely drilling fluid deep invasion, or losses, where temperature change is not sufficient to separate reservoir fluids. Overall the tool was applied to multiple geological settings, with fluids ranging from heavy oil, to water and gas with high success. This method allows for a reduction in uncertainty during completion in development producers, while allowing for better potential exploration secondary reservoirs all while having no additional cost associated with acquiring additional data for the high precision temperature is already an auxiliary measurement for all modern formation testing tools.