Kansas Geological Survey Open-file Report 2003-31

Input data for Reservoir Simulation

3 Layer model of the reservoir
Analytical aquifer below the bottom layer
Grid cell size 110 ft by 110 ft

Reservoir temperature = 120^oF
Oil Gravity = 40 API
Gas gravity = 0.8 (Air = 1.0)
Water salinity = 75,000 ppm
Initial reservoir pressure = 2,000 psi

Wells produced at 100 psi bottomhole pressure

Aquifer porosity = 0.15
Aquifer permeability = 0.1 md

Initial permeability estimated from Permeability-porosity cross plot

K= 0.746 e ^18.9 or K = 10^{(Phi*100)*0.082 - 0.127}
where Phi is in fraction

How to generate intial Sw distribution lacking resistivity logs at most wells?

Step 1

Starting permeabilities in Layers 1, 2, and 3 were 8 md, 12 md, and 8 md. The relative
permeability-capillary pressure control panel for Layer 1 (K = 8 md) is shown below. The starting Rel K exponents were m = 0.5 and n = 3.1.

These values result in too high an oil and water production.

Step 2

To reduce fluid production, the permeabilities in Layers 1, 2, and 3 were changed to 4 md, 6 md and 8 md. The result of changing K from 8 md to 4 md on Swi and Sorw is shown below.

Rel K exponents: m = 0.2, n = 4.5

Step 3

Finally, the decline curves were matched by adjusting the Rel K exponents, m = 0.2 and n = 5.0. Change of these exponents did not effect the Swi and Sorw but changed the Krw and Krow values.

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