六盘山盆地下白垩统马东山组页岩气勘探潜力评价

为了研究六盘山盆地下白垩统马东山组的页岩气勘探潜力，对马东山组的泥页岩样品进行了一系列储层物性、孔隙结构和有机地化的分析试验。研究表明：六盘山盆地马东山组泥页岩有效厚度较大，平均1215m，脆性矿物含量高，在80%以上；在孔隙特征方面，该套泥页岩主要发育微小孔，发育少量微裂缝，孔隙度均值为397%，平均可动流体饱和度为276%；在地化特征方面，该组泥页岩总有机碳含量平均101%，有机质类型以Ⅱ型干酪根为主，镜质体反射率平均094%。综合考虑泥页岩有效厚度、有机质丰度、有机质类型、热演化程度和孔隙特征等因素，六盘山盆地马东山组具备页岩气富集与成藏的条件，并可优选出两个页岩气勘探有利区：分别是海原凹陷东部有利区和固原凹陷中部有利区。经计算，两个勘探有利区的页岩气资源总量约为0364亿m3。

SHALE GAS POTENTIAL OF THE LOWER CRETACEOUS MADONGSHAN FORMATION OF LIUPANSHAN BASIN

This paper evaluates the shale-gas potential of the lower Cretaceous Madongshan formation of Liupanshan basin based on Madongshan formation mudstone and shale reservoir, porosity, and organic chemistry. This study indicates that the mudstone and shale is 121.5m thick on average, above 80% in brittle minerals content, 3.97% in porosity characterized by micro pore with less micro fissures, 2.76% in movable fluid saturation, 1.01% in total organic carbon chiefly in type II Kerogen, 0.94% invitrinite reflectance. All these features make Madongshan formation of shale gas potential. This paper highlighted two potential areas, the eastern Haiyuan sag and the central Guyuan sag, with their total shale-gas volume estimated to be 36.4 million cubic meters.