Use of magnetic resonance imaging as a tool for the study of foamy oil behavior for an extra-heavy crude oil. T-2/viscosity correlation with respect to pressure

The purpose of this work is to present the results of the phase behavior st udy for a live heavy oil during a pressure depletion process using magnetic resonance imaging (MRI) as a tool to characterize foamy oil phenomena. The experiments were carried out in the pressure range of 13.1 to 1.4 MPa. Sig nal intensity images were obtained at each pressure and with respect to tim e, that is, approximately for a total time of 3 h after each pressure chang e. It is possible to see a variation in intensity across the sample. These changes can be associated with changes in mobility as well as segregation o f the oil. It was also possible to observe that what we trust is the format ion of gas channels at the last two pressure values, as it comes out of sol ution. A correlation between the transverse relaxation time T-2 and tempera ture was established with the aim of producing one between T-2 and viscosit y. In this way viscosity maps for the live oil were obtained as a function of pressure and time. It was observed that above the bubble point, the visc osity maps varied from low to high to low with respect to time for the same pressure. Below the bubble point the situation is reverse. The viscosity m ap changes from high to low to high with respect to time for the same press ure. The study shows the potential use of MRI to follow viscosity changes d uring pressure depletion test in a PVT MRI cell.