金衢盆地上白垩统金华组湖相页岩油气地质特征

以金衢盆地白垩系金华组为研究对象,在钻井资料分析的基础上,结合区域沉积背景,通过分析暗色泥页岩有机质丰度、厚度和分布范围,研究和探索了金衢盆地上白垩统金华组湖相页岩油气地质特征。金衢盆地金华组湖相暗色泥页岩样品的有机质丰度特征表明,TOC值一般小于0.5%,属于非烃源岩,个别样品达到1.57%,属于优质烃源岩; 富有机质层段以富砂夹泥型或富泥夹砂型为主,具多产层特征,盆地北部凹陷具备一定的页岩油气勘探潜力。金华组湖相暗色泥页岩主要发育在西北部衢州—龙游沉积中心区,区域较为局限,厚度不均,范围5~100 m,平均孔隙度3.867%,平均最大渗透率0.087 2×10^-3 μm²,属于典型的致密型储层。将富有机质层段砂泥地层作为一个整体进行页岩油气勘探,源储一体是今后陆相页岩油气的重要勘探思路。

Geological characteristics of lacustrine shale oil and gas of Jinhua Formation in Upper Cretaceous in Jinqu Basin

This paper took the Jinhua Formation of Cretaceous in Jinqu Basin as the research object. According to the regional sedimentary background and the drilling data, the authors analyzed the organic matter abundance, thickness and distribution of dark shales, and studied the geological characteristics of lacustrine shale oil and gas of Jinhua Formation in Upper Cretaceous in Jinqu Basin. The organic matter abundance shows that TOC value is commonly less than 0.5%, belonging to non-source rocks. While the value of a few samples reaches 1.57%, belonging to quality source rocks. The organic-rich layers are mainly sand-rich and mud interbed or mud-rich and sand interbed, and they are multiple productive targets. The northern sag of the basin has a certain exploration potential of shale oil and gas. The dark lacustrine shales in Jinhua Formation are mainly developed in the northwestern Quzhou-Longyou depositional center areas. The developed areas are limited and thickness of shales is 5-100 m. The average porosity of shales is 3.867%, and the average maximum permeability is 0.087 2×10^-3μm², showing that the shales are a typical tight reservoir. The organic-rich layers are taken as a whole for shale oil and gas exploration. And it is an important direction for future terrestrial shale oil and gas exploration that the oil source rocks are the reservoir.