| 主权项 |
1. A method for determining rheological properties of a fluid, comprising the steps of:
a. providing an open-bore tube and defining within said bore a three dimensional grid (3DG) of voxels, with each voxel Voxi having a position (xi, yi, zi) in said 3DG; defining at least two different cross sections, namely inlet cross section (ICS) and outlet cross section (OCS); and defining a volume of interest (VOI) within said bore between said ICS and said OCS; b. obtaining a database of rheological properties of said fluid; c. applying a pressure gradient to said bore between said ICS and said OCS, thereby flowing said fluid through said tube; d. NMR imaging said fluid within said VOI, said image having a plurality p of slices, each slice comprising a plane within said 3DG; e. from said image, for each of said voxels Voxi, determining a velocity for said fluid vi, f. for each of said voxels Voxi, from said velocity vi, calculating shear rate values (SRV); whilst, before or after determining a pressure gradient between said at least one ICS and said at least one OCS and thereby calculating shear stress values (SSV) for each voxel Voxi, from said SRV and said SSV determining at least one rheological property RPi, for each voxel Voxi; g. comparing, for said at least one rheological property, RPi calculated for voxel Voxi to stored RPi for voxel Voxi from said database, thereby determining the difference in rheological property DRPi for voxel Voxi; and h. from the set of said DRP, calculating 3D variations in said rheological property, therefrom determining the difference in rheological property DRPi as a function of position (x,yi,zi) in said grid; wherein the resolution of said difference in rheological property DRPi is multiplied by about p compared to the per-slice resolution. |
