Prediction of hydrocarbon charge

PetroConsult offers studies in the prediction of hydrocarbon charge. Through the mapping of hydrocarbon occurrences and their migration pathways through time and space, and its integration with charge modelling, we can offer a more 'observational' approach. All observational data of hydrocarbons are mapped and explained within an understanding of the known source rock distribution, their modelled generation and expulsion and the migration pathways through time.

Deliverables

Broadly speaking, the main product of such a study should be prediction of the hydrocarbon migration “front” for the different exploration plays.  Maps showing these migration fronts would be produced for each carrier bed, integrating hydrocarbon shows in well and seismic data and showing the occurrence of hydrocarbons on the surface from geochemical survey and remote sensing data. As a lot of this data is based on “subjective” interpretation each occurrence of hydrocarbons should be flagged with an estimate of its validity.  A report would be provided. In addition, estimates of hydrocarbon charge volume and type, and probability could be provided on a prospect level.

Hierarchy of Hydrocarbon shows

Hydrocarbon shows from well data

• Mud-log well data (in-house reports and floppy discs)
• GC, GC-MS (MS) data from oil-sample analyses (contractor reports)
• Analyses of biomarkers; biomarker applications for typing work and migration pathway mapping (contractor and specialist reports).

Seismic anomalies related to hydrocarbons

• DHI – amplitude anomalies, flat-spots, gas chimneys, gas trains etc (use existing regional maps and seismic interpretation reports or do a regional interpretation on a workstation)
• Secondary features e.g. bioherms or pock marks related to seepages (interpreted on workstation)

Geochemical surveys

• Sea bottom surface geochemical anomaly data (contractor reports)
• Water column “sniffer” data (contractor reports)
• Ground “truthing” data – skimmer samples (contractor reports)

Remote sensing data

• Airborne data
• Aerial photographs
• Microwave or radar data
• Ultra-violet or infra-red data

Fluorescence methods

•    Passive
•    Active (including ALF data)

Satellite data

• Synthetic Aperture Radar (SAR)
• Landsat data

Source rock information

• TOC and Rock-Eval data (contractor reports)
• SR from well-log data
• SR distribution and thickness (existing company reports)

Maceral data (microscopy work) on source rock samples (contractor reports)

• Calculate initial source rock quality (in-house reports?)
• Maturity measurements (contractor reports)
• Source rock quality determinations

Thermal modelling data and generation / expulsion prediction

• AFTA and ZFTA measurements and existing data

Methodology

Secondary migration HC pathways mapping through time (regional seals and reservoirs, faults and fractures). This may exist in company reports, or may be collated from regional studies – it is also possible to provide seismic interpretation services for the study.

Determine fault and fracture distribution

Map Surface seeps and slicks

Surface seeps that generate oil slicks cannot be produced by migration direct from a generating source. They are related to the escape of hydrocarbons from a trap, albeit perhaps economically insignificant. Integration with geology, geophysics, and mapping of migration pathways is critical to understand the occurrence of seeps at the sea surface. It is important to incorporate mapping of seismic anomalies. Oil on the sea surface originates from natural seeps on the sea floor, which passes through the water column as a thin coating on gas bubbles. These gas plumes are often visible on high-resolution seismic data. Gas effects, such as pock marks, gas trains and chimneys are often visible on conventional seismic data.

Information provided by: http://www.petroconsult.com.au