# 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 + rbkd /q R = retardation factor rb = bulk density = rs(1-q) rs = solids density q = porosity kd = (soil) distribution coefficient = foc Koc foc = fraction organic carbon Koc = organic carbon/water partition coefficient
Solids Density (rs) (Try 2.65 g/cm3)
Porosity (q ) (Try 0.30)
Bulk Density (rb) Calculated Result
Fraction Organic Carbon (foc) (Try 0.0001)
Organic Carbon Partition Coefficient (Koc)
Koc 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.