ORFA, an acronym for “One Run Fixed A”, was developed by Sirius jointly with our partners at StratoChem Services. ORFA converts Rock-Eval or SRA pyrolysis data from a single run into a set of activation energies, once the user has specified the desired A factor. ORFA will also break the bulk or total-hydrocarbon kinetics into separate kinetics for oil and gas generation, using a method similar to that published by Waples and Mahadir Ramly (2001). In addition, the user can easily adjust the Ea spacing or change the Ea values to non-integral values in order to achieve better resolution, or edit the Ea distribution to remove the effects of baseline drift and contamination by bitumen or OBM. Having ORFA in house will enable those interested in source-rock kinetics to examine multiple interpretation scenarios and choose intelligently the solution that best meets their needs.
ORFA is being marketed by StratoChem Services. Please contact us or StratoChem for further information about ORFA’s capabilities and cost.
Examples of output from ORFA are shown below.
Left: Plot showing excellent fit between measured laboratory pyrolysis curve (yellow) and pyrolysis yield predicted from using the kinetic parameters derived by our ORFA software (cyan). Right: Activation-energy distribution derived by ORFA that was used in calculating the cyan pyrolysis curve. Not shown here is the A factor, which was specified as 2*1014s-1.
Top: Kinetics for the Green River Shale, which generates about 10% gas. Bottom: Kinetics for the Abu Roash “D”, which is a Type III kerogen that generates a higher percentage of gas. Cyan histograms show total hydrocarbon kinetics, while the other two displays divide those kinetics into oil (green) and gas (red) kinetics, displayed in two different formats. All this output was derived using our proprietary ORFA software.
Ea spacing set to 0.2 kcal/mol. Left: fit to measured pyrolysis curve (yellow). Right: Ea distribution prior to editing.The value at 60 kcal, which sums the effects of baseline drift, would be edited out in the final interpretation.