Environmental Modeling Community of Practice

Modeling Subsurface Petroleum Hydrocarbon Transport

Modeling Framework

It's inevitable that in a modeling course, the transport equations are discussed. One of the purposes of the course is to make the equations less intimidating and to show how to read these equations to learn what is included in a specific model. Various calculations that can be made from the equations are implemented in JavaScript and Java Applets.

Here's a JavaScript calculator for determining the retardation factor.

Retardation Factor Calculator

Retardation Factor R = 1 + r_bk_d /q

R = retardation factor
r_b = bulk density = r_s(1-q)
r_s = solids density
q = porosity
k_d = (soil) distribution coefficient = f_oc K_oc
f_oc = fraction organic carbon
K_oc = organic carbon/water partition coefficient

Solids Density (r_s)

(Try 2.65 g/cm³)

Porosity (q )

(Try 0.30)

Bulk Density (r_b)

Calculated Result

Fraction Organic Carbon (f_oc)

(Try 0.0001)

Organic Carbon Partition Coefficient (K_oc)

K_oc value

Retardation Factor (R)

Calculated Result

Other calculators are used throughout the course for calculation of various quantities and unit conversions. The calculators form an on-line site assessment tool called OnSite which can be used at anytime.

For more complex tutorials a Java Applet is being developed.

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