阿巴拉契亚盆地Marcellus页岩气藏地质特征及启示

Characteristics and Implications of Marcellus Shale Gas Reservoir,Appalachian Basin

随着水平钻井及水力压裂技术的进步,北美页岩气得以成功开发并成为北美最为重要的非常规天然气之一,其中阿巴拉契亚盆地Marcellus页岩气藏作为北美资源量最大的页岩气藏为世人所瞩目。根据研究资料,分析了泥盆系Marcellus黑色页岩厚度、有机质类型及丰度、成熟度、孔渗等参数,重点分析了页岩微裂缝的特征及发育机制。将Marcellus页岩气藏地质特征与目前北美页岩气产量最大的FortWorth盆地Barnett页岩气藏进行对比分析,二者不仅具有相似的构造及沉积背景,并且Marcellus含气页岩在多项石油地质指标上优于Barnett页岩,认为Marcellus页岩气为北美最具发展前景的页岩气区带。我国特殊地质条件决定不能直接套用北美页岩气成藏理论,只要有足够大面积与页岩厚度,黑色页岩大多可形成页岩气藏。综合研究及权衡各地质参数,认为中国上扬子地区多套海相页岩和其他地区陆相暗色页岩地层均具有良好页岩气潜力。

With the development of horizontal well technique and hydraulic cracking skills,shale gas has been developed successfully and has become one of the most important unconventional gas types.In particular,Marcellus shale gas,which owns the largest resource in North America,has been paid great attention to.According to former research data,this paper analyzed the thickness,organic matter type and abundance,maturity,porosity and permeability,etc.of Devonian Marcellus black shale,and focused on the analysis of characteristics and formation mechanism of microfracture.Comparing the geological features of Marcellus shale gas reservoir with those of Barnett with the highest production in the Fort Work Basins,North America,it was discovered that both reservoirs owned similar structural and depositional settings,and Marcellus shale had better petroleum geology indexes in some perspectives and was considered to have broad prospect for development in the future.North America's shale gas play theory was not suitable for China,due to China's special geological conditions.A conclusion was drawn that with enough area and thickness,most black shale was likely to develop shale gas plays.It was indicated that several marine dark shale layers in the Upper Yangtze region and non-marine dark shale layers in other regions in China had great potential in shale gas storage,through integrated research and balance of geological indexes.