济阳坳陷下古生界碳酸盐岩烃源岩评价

Evaluation of Lower Paleozoic carbonate source rocks in Jiyang depression

应用生油生气量计算模型、岩石吸附油气量计算模型、油溶水溶气量计算模型、扩散气量计算模型计算了济阳坳陷(车镇、沾化和东营)下古生界碳酸盐岩的生烃量和残留耗散烃量,进而根据物质平衡原理计算出排烃量,根据排烃量的大小对目标层进行了烃源岩评价。结果表明,车镇、沾化和东营凹陷下古生界碳酸盐岩均为非油源岩、非气源岩。结合车25井、孤古2井和草古101井有机质成烃剖面,认为造成研究区烃源条件差的原因是有机质丰度过低。

In Jiyang depression, Lower Paleozoic Cambrian and Ordovician carbonate source rocks are widely distributed. And whether the carbonate source rocks can be commercial oil source rocks and gas source rocks or not is an important problem, which concerns the direction of exploration and investment. In this paper, oil and gas quantity of generation and losing of Lower Paleozoic carbonate rocks in Jiyang depression （Chezhen, Zhanhua and Dongying） have been calculated by the calculation models of oil and gas quantity of generation, oil and gas adsorption in rocks, gas dissolving in oil, gas dissolving in water and gas diffusion. According to the material balance principle, quantity of oil expelling （ = net oil - remained oil） and gas expelling （ = gas quantity of generation - gas quantity of adsorption - gas quantity dissolving in oil - gas quantity dissolving in water - gas quantity of diffusion） have been calculated, which can be used to evaluate the oil source rocks and gas source rocks of target source rocks. The result shows that Lower Paleozoic carbonate rocks in Chezhen, Zhanhua and Dongying sags are not oil source rocks; those in Chezhen and Dongying sags are not gas source rocks; and that in Zhanhua sag is bad gas source rock. Combining with hydrocarbon generating section of organic matter of Wells Che 25, Gugu 2 and Caogu 101, it is concluded that the bad evaluation of target source rocks is due to the lower organic matter abundance.