Due to the spike in energy prices, there is intense interest in locating and
developing additional oil and gas reserves. These reserves are located in sedimentary
basins and predictions can be made of the quantity of oil and gas in these reservoirs
by the identification and characterization of petroleum source rocks. However,
this requires an understanding the burial and thermal maturation histories of
the strata in these basins.
Commonly, this is done by measuring the vitrinite reflectance of kerogens,
the organic components of the source rock, with instruments such as the QDI
CoalPro™ Vitrinite Reflectance Measurement System. The level of vitrinite
found in kerogens is an indicator of the thermal maturity of the petroleum source
rock and therefore allows predictions of the amount and timing of petroleum
generation.
Vitrinite is a maceral that is a key component of kerogen, the organic components
of petroleum source rocks. By measuring the amount of vitrinite, the thermal
maturity of the source rock can be determined and an estimate can be made of
the amount of oil or gas contained within a particular reservoir. The procedure
has been delineated in ISO and ASTM standards and requires a microphotometer:
a device designed to measure the intensity of light reflected from a microscopic
sampling area at 546 nm. The procedure is simple: the microphotometer measures
the amount of light reflected from the kerogen at hundreds of points after which
a statistical analysis is done. The results of the statistical analysis are
used to determine the amount of vitrinite in the petroleum source rock and therefore
its thermal maturity. As hundreds of measurements need to be done on each sample,
this used to be a very time consuming process. Today, instruments such as the
QDI CoalPro™ from CRAIC
Technologies can automate this process and dramatically improve the number
of samples analyzed in a day.