A variety of pyrolysis systems can be used to obtain source rock evaluation and other data. Systems with bulk flow capabilities are best used to screen samples for subsequent detailed analysis, but data must be interpreted in the light of possible mineral-pyrolysate interactions. Non-indigenous hydrocarbons can be detected by the same techniques, but pyrolysis-FID/-gc or alternatively pyrolysis-gc plus pyrolysis-bulk flow are required to identify and differentiate migrated hydrocarbons and refined petroleum products. Screening can be carried out in the laboratory or at the well location. In the latter case, data can be used for on-site decision making, as well as providing the groundwork for subsequent geochemical studies. Pyrolysis-FID/-gc provides the most comprehensive means for screening in both laboratory and well-site situations. For detailed geochemical analysis, pyrolysis-gc is the most versatile technique, providing both quantitative and qualitative ways to identify kerogen type, classify bitumens, and recognize contamination.

The primary objective of this paper is to demonstrate the successful application of maturation modelling using velocity-based thermal conductivity in the whole cycle of hydrocarbon exploration (frontier, developing and mature) on the Halten Terrace, Offshore Norway. This seismic geochemical method, used as a critical technique for selecting a favourable block in the early stages of exploration in the early 80s, enabled Conoco and its partners to make the first oil discovery and the subsequent discovery of the giant Heidrun Field in the area north of the 62nd parallel.Additional data (modelled and measured) on the thermal conductivity and Ro values are now available, and provide an excellent opportunity to compare the original (pre-drilling) basin models and related modelled results of the early 80s with 1990s (post-drilling) state-of-the-art data and models. The results of the comparative study indicate that the velocity-based conductivity compares very well with measured data, particularly in an overpressured area where conventional porosity (modelled) based thermal conductivities were inadequate. The pre-drilling predicted values of heat flow, geothermal gradient and vitrinite reflectance (based on Arrhenius equation) and oil window limits also compared favourably with post-drilling measured results. Thus, the method of calculating thermal conductivity from seismic data provides a useful tool to integrate geochemistry and geophysical (seismic) data, to calibrate maturation models, and to enhance the value of geochemistry and basin modelling in hydrocarbon exploration.for basin modelling and hydrocarbon exploration.

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