三江盆地下白垩统穆棱组页岩气成藏地质条件研究

采用有机地球化学分析测试、X衍射荧光分析、高压压汞、扫描电镜、低温氮气吸附等方法,对三江盆地下白垩统穆棱组暗色泥页岩页岩气成藏地质条件开展系统研究,研究结果表明穆棱组暗色泥页岩分布面积较广泛、累积厚度大、TOC含量中等,有机质主要处于成熟-过熟阶段,以Ⅱ2型干酪根为主,说明有机质已进入大量产气阶段;泥页岩中石英、长石及碳酸盐等脆性矿物含量较高;存在一定量的中孔、大孔和微裂缝,为低孔隙度、低渗透率的孔隙结构类型。据现有钻探资料,充分显示了下白垩穆棱组统暗色泥页岩较好的含气性,与美国主要页岩油气产区和中国发现的陆相页岩气层段相对比,三江盆地穆棱组各项参数达标,具有较好的页岩气勘探潜力。

Geological conditions of shale gas reservoirs of Lower Cretaceous Muling Formation in Sanjiang Basin

A systematic study was undertaken on the geological conditions of shale gas reservoirs of dark mud shale in the Lower Cretaceous Muling Formation, using organic geochemical analysis, X-ray diffraction analysis, high pressure mercury injection, scanning electron microscopy and low temperature nitrogen adsorption. The results show that the dark mudstone of the Muling Formation is widely developed, with significant cumulative thickness and medium TOC content. The organic matter that mainly consists of Ⅱ2 kerogen is in the mature to over mature stage, indicating that the organic matter has entered the stages of significant gas production. The content of brittle minerals such as quartz, feldspar and carbonate in shale is high. There exists certain amount of pore porosity and micro fractures, which is a type of pore structure with low porosity and low permeability. According to drilling data, the dark mud shale of Lower Cretaceous Muling Formation has a good gas-bearing ability. Compared with major shale oil and gas fields in the US and continental shale gas deposits in China, parameters of Muling Formation reach the standard, indicating that it has a good potential for shale gas exploration.