Impact of variable formation thickness on pressure transient behavior and well test permeability in fluvial meander loop reservoirs

The assumed permeability of a reservoir is largely dependent on where the formation was intersected if the formation thickness varies with the position. The misinterpretation of the reservoir permeability can result in erroneous calculation of the reservoir productivity index. A numerical simulation was performed to examine this case for a fluvial meander loop reservoir embedded in an impermeable matrix. The well test interpreted permeability depended on the intersection ratio (ratio of wellbore intersected thickness to the maximum thickness) and the pinch-out ratio (ratio of the minimum reservoir sandbody thickness to the maximum thickness).