济阳坳陷沾化凹陷东部热史模拟研究

根据区内钻井测温和镜质体反射率(Ro)资料,采用岩石圈和盆地尺度相结合的分段线性热演化模型,对该区的热史进行了恢复。结果表明:(1)该区自古新世以来,热流的演化形态近似于“马鞍型”,中间有二次回升,但回升的幅度逐渐变小;古新世早期的大地热流值为83.6mW/m2,相当于现代活动裂谷的热流值,今大地热流值为63mw/m2,接近全球大地热流的平均值。(2)该区主力烃源岩经历了持续的受热过程,现今仍处于“生油窗口”内,在深度上具有较大的油气赋存空间,热演化背景十分理想。上述模拟结果可以用渤海湾盆地的裂谷演化模式进行较好的解释,并对胜利油田沾化凹陷的油气勘探工作具有一定的指导作用。 

GEOTHERMAL HISTORY RECONSTRUCTION OF ZHANHUA SAG,JIYANG DEPRESSION

Based on available well temperatures and vitrinite reflectance (Ro) data, geothermal history of Zhanhua sag, Jiyang Depression was reconstructed with synthesizing lithosphere-scale and basin-scale multi-linear medel offered in this paper. The study result indicates: (l ) the heat flow evolution curve show a general tendency of decreasing slowly interrupted by two picking up periods that shapes' a saddle' from the Paleocene to the Present. The ca1culated heat flow is about 83. 6 mW/m in the early Paleocene corresPOnding to active rift region, however, the present heat flow gets down to 63mW/m as the global average value. (2) the main oil bearing layers exPerienced long term slowly heating process, subsequently, it is sti1l at the 'oil generation window', and has a wide range depth for oil existence. ffe, the geothermal evolution background is favorable to oil genertdri. The conclusion can also be further prooed by the rifting medel of Bohaiwan Basin, and is useful to oil oploration in this area.