C.W.D. Milner, 1987. "Geochemical Analyses of Sedimentary Organic Matter and Interpretation of Maturation and Source Potential", How to Assess Maturation and Paleotemperatures, F. L. Staplin, W. G. Dow, C. W. D. Milner, D.I. O’Connor, S.A.J. Pocock, P. van Gijzel, D.H. Welte, M.A. Yükler
Download citation file:
Petroleum is sourced from sedimentary organic matter that has been exposed to a sufficient combination of temperature and time to cause hydrocarbon generation. The amount and types of organic matter and the time-temp integral determine how much and what kind of hydrocarbons are yielded. It is possible to directly measure or to make predictions about these variables from chemical analyses of the organic matter. The most fundamental source rock parameter is the total amount of organic carbon present in the sediment. Another commonly used parameter is the amount of extractive hydrocarbon in the organic matter. This can be analyzed, usually by various chromatographic methods, over the entire hydrocarbon molecular size range from gases to solid bitumens, and for all classes of hydrocarbons. Similar predictions can be made by performing elemental analyses on the insoluble organic matter or kerogen. Today, more and more use is being made of pyrolysis techniques wherein organic matter is subjected to a simulated maturation process in the lab.
Figures & Tables
How to Assess Maturation and Paleotemperatures
The application of organic matter studies in petroleum exploration had its start with the recognition of “rank” in coal. During the period of 1900–1925, both physical and chemical methods were developed for determination of the degree of low grade metamorphism of particulate organic materials, or palynodebris in coals and other sediments. Measurements of the relative metamorphism (maturation level) which are based on physical properties are generally quick, cheap, and qualitative to semiquantitative. Those based on chemical analyses are less rapid and tend to be more quantitative. Each method has advantages and disadvantages and they often are combined. Papers included in this course consider methods based on particulate organic matter, reflectance, fluorescence, and geochemistry. A method for integrating the data into a three-dimensional model is included.