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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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In recent years, several attempts have been made to explain the formation of solar spicules. One of the earlier models was proposed by Kuperus and Athay (1967) who argued that the downward conduction of heat flux from the corona (which is a constant in the temperature range 105-106K (Athay, 1966)) into the base of the chromosphere-corona transition region could not be disposed of by radiation losses only and they suggested the spicules as a possible mechanism for maintaining the energy balance in that region. However, this mechanism is valid only in the spicular regions and fails to apply to the interspicular regions which cover most of the solar surface. Kopp and Kuperus (1968) propose the channeling of heat along the magnetic field lines in the interspicular regions to the supergranulation boundaries and its possible role in the formation of spicules. They argue that only a relatively small fraction of the downward conductive flux enters the 105K level in the relatively large interspicular regions and can be disposed of by radiation losses. Hence, no kinetic motions are observed in this region. The remainder is diverted to the spicular regions. In the present note we examine the possibility of putting an upper limit on the density enhancement of the spicules as compared to the surroundings, in the region of their formation.Let ~ be the fraction of the conductive flux F c reaching the 105K level in the interspicular region. If this flux is deposited in a layer of thickness AZis and since no dynamic motions are observed, all of the conducted heat is radiated. Therefore, if A s is the area of the Sun and Asp is the area covered by spicules, we have in the interspicular region:AZis where fl is a constant and has the value (OrraU and Zirker, 1961) fl = 1.58 x 1026 ergs cm 3 g-2 s in the temperature range 104-106K and ~o is the unperturbed density. The flux (1 -~)F~ from the interspicular region is directed to the centers of the rosettes, due to magnetic fields. Therefore, the total conductive energy/sec available in the spicular region is E c = [(1 -~) F~(A S -Asp ) + FcA j ergs s -1 . (2) Solar Physics 42 (1975) 6%70. All Rights Reserved Copyright 9 1975 by D. Reidel Publishing Contpany, Dordrecht-Holland