ABSTRACT
Recent developments in well testing have focused on obtaining the properties of each layer in a multi-layered reservoir. Quantification of the dynamic reservoir description includes determination of the layer permeabilities and skins, effective drainage boundaries, and zone average pressures. The subject of this paper is a new well test procedure for acquiring the transient flowrate and pressure response of any single layer in a commingled system. Convolution of the bottom hole flowing pressure with the layer flowrate produces a response function equivalent to the pressure transient that would be measured if the layer were packed off in the well.
A major advantage of this test is that wellbore effects on the transients are minimized, thus enabling reservoir characterisation in the vicinity of the wellbore that is not possible by any previously reported means. Hence, the early time response affords the possibility of quantifying partial penetration skin or the radial extent of an altered zone.
A second advantage is the possibility for long duration testing of the single layer with little interuption in the well production. If the interval tested by this method is not communicating vertically with adjacent layers in the reservoir, the recorded transients can be evaluated for reservoir heterogeneities such as dual porosity behavior.
