Estimation and calibration of heat flow history in sedimentary basin modeling for hydrocarbon resources

近年来，开发了几种计算机辅助盆地油气资源模拟系统。在模拟油气生成、排烃和聚集的各种模拟条件中，烃源岩的热史是最重要的模拟条件之一。用地球物理方法得到的热流历史虽然不太精确，但可以提供有关热流变化模式的有用信息。另一方面，地球化学方法获得的结果相对精确，但不能提供足够的热流历史信息。本研究的目的是建立一种基于多种方法的新的、交互式的方法来评估沉积盆地的热流历史，通过对镜质体反射率、甾烷异构体比率和甲基菲指数的研究，揭示它们作为热指示剂的有用性。根据对MITI Niigata-heiya和MITI Takada-heiya钻孔样品的分析结果和可能的热历史，阐明了它们在成岩过程中的动力学行为。它们的动力学参数，如表观活化能和指前因子，因此，确定。这些有机热指标的动力学重建在Dolna Kamchia凹陷，保加利亚东北部的热流历史。利用计算机模拟系统（MAT 98），通过地球物理、地质和地球化学方法的交互过程标定热流历史。本研究为热流历史重建的计算机辅助交互建模奠定了基础。

Several computer aided basin modeling systems for hydrocarbon resources have been developed recently. Among various simulation conditions for modeling hydrocarbon generation, expulsion, and accumulation, the thermal history of the source rocks is one of the most important simulation conditions. The heat flow history obtained by geophysical approach is not so precise, but can give useful information regarding the pattern of heat flow change. On the other hand, that obtained by geochemical approach is comparatively precise, but does not give sufficient information on the history of heat flow. The purpose of our research is to establish the new and interactive approach based on various methodologies to assess the heat flow history in the sedimentary basins.Vitrinite reflectance, sterane isomer ratio, and methylphenanthrene indices are examined to reveal their usefulness as thermal indicators. Their kinetic behaviors during diagenetic process were clarified based on their analytical results and possible thermal histories estimated by geological consideration on bore hole samples from MITI Niigata-heiya and MITI Takada-heiya. Their kinetic parameters such as apparent activation energies and pre-exponential factors are, consequently, determined. The kinetics of these organic thermal indicators are applied to reconstruct the heat flow history in the Dolna Kamchia depression, northeastern Bulgaria. The heat flow history is calibrated through the interactive process of geophysical, geological and geochemical approaches with a computer modeling system(MAT98). The present study established the basis of computer aided interactive modeling for the reconstruction of heat flow history.