Mathematical Modelling of TransportProcesses During Wellbore Heating in TarSand and Bituminous Reservoirs

摘要

`Enhanced oil recovery (EOR) processes sometimesinvolve wellbore heating by means of electromagneticradiation, electrical heating, or steam injection. When awellbore is heated in tar sands and bituminousreservoirs, many thermo-physical properties of bitumenand rock matrix can change significantly and therebyalter the fluids and heat flow behaviour.This paper presents the development of a mathematicalformulation that describes the flow behaviours of heatand fluids around a wellbore during the initial period ofheating in tar sands and bituminous reservoirs. Themodel shows that the transient temperature distribution isnot affected significantly by convection. However, thepressure distribution exhibits an abnormally highpressure build-up resulting from the relative thermalexpansion of in-situ bitumen in the region where the temperature is slightly higher than the reservoirtemperature.The mathematical model can be used to obtainpredictions of pressure-temperature distributions aroundheated wellbores, well communication time required insteam assisted gravity drainage (SAGD) process, andwell stimulation and absolute permeability improvementresulting from progressive shear dilation in lowpermeability bitumen and tar sand reservoirs.