Source rock quality and properties
BGS expertise in basin analysis and seismic processing, organic chemistry, palynology and palynofacies analysis, and mineralogy and petrology is available to assess source rock properties.
Factors determining source rock quality include:
- net to gross organic-rich shale thicknesses
- total organic carbon (TOC)
- kerogen type
- thermal maturity
- porosity and transport properties
- fracture properties
These characteristics are a function of original depositional setting, subsequent geological history and mineralogy.
Basin analysis
Our capability includes:
- use of conventional oil and gas well data to identify potential targets, for example maturity indices, total organic carbon and shale formation crops and thicknesses
- identification of 'hot shales' from gamma ray and spectral gamma ray logs
- determination of net to gross organic-rich shale thicknesses from wireline logs
- identification of gas kicks and hydrocarbon shows in wells
- analysis of source of gas in conventional reservoirs, based on gas composition and carbon isotope analysis
- determination of fracture orientation from borehole breakouts
- use of 2D seismic reflection data and geophysical logs to identify basin controlling (syn-sedmentary) faults and isopachs to determine thickening of key formations
- mapping of key unconformity surfaces with supercrop, subcrop and depth data in GIS
- use of seismic velocity as maturity indicator and to indicate uplift
Organic geochemistry
The BGS Organic Geochemistry Laboratory is equipped to undertake research on the thermal maturity of shales, kerogen typing and organic richness using TOC, Rock-Eval pyrolysis and infrared spectroscopy. Gas chromatograph/mass spectrometer-pyrolysis characterisation at the molecular level is used to investigate kerogen type.
Palynology and palynofacies
The BGS Palynology Laboratory provides supporting data and interpretations for source rock evaluation in the form of kerogen preparations for visual kerogen analysis, which identifies what makes up the organic matter in a sample and in what proportions (e.g. amorphous organic matter, woody material), and for ultra-violet fluorescence microscopy, which indicates maturity and/or oxidation of a sample.
Mineralogy and petrology
The BGS Mineralogy and Petrology Laboratories have the expertise and facilities to carry out x-ray diffraction (XRD), petrography and microanalysis of shales, and therefore to investigate the fracture properties (brittleness versus ductility, based on clay content as determined by XRD) and porosity of shales.
Contact
Contact Prof. Mike Stephenson for further information or enquiries about BGS shale gas consultancy services
