【摘要】 东海盆地西湖凹陷天然气资源丰富,油气勘探发现古近系砂岩储层渗透率普遍较低,低渗透气藏在多个含油气构造均有分布且表现出致密砂岩气藏特征。根据致密砂岩气藏成藏机理对西湖凹陷的石油地质条件进行了分析,并与致密砂岩气勘探开发程度较高的鄂尔多斯盆地进行了对比。结果表明,低渗透砂岩大范围分布背景下西湖凹陷具备形成致密砂岩气藏的构造、沉积、气源岩、储层及封盖保存条件,埋深≥3 500m的古近系砂岩普遍进入致密储层阶段,是致密砂岩气藏发育的有利层位,与鄂尔多斯盆地在致密砂岩气藏形成的生-储-源储配置条件上具有一定的相似性。综合分析认为,西湖凹陷初步具备形成致密砂岩气藏的地质条件。更多还原

【Abstract】 Natural gas is abundant in the Xihu Sag,East China Sea Basin.According to the data of oil &gas exploration,the permeability of Paleogene sandstone reservoir is generally low and the low permeabile gas reservoirs are distributed in several oil & gas bearing structures which show the charateristics of a tight sandstone gas reservoir.Research results of the petroleum geology of Xihu Sag(based on the accumullation mechanism of tight sandstone gas reservoir)and compassion researches between Xihu Sag and Ordos Basin which exploration and development degree of tight sandstone gas reservoir is higher suggest that there are good formation conditions for tight sandstone gas reservoirs in structure,sedimentary,source rock,sealing and preservation conditions in Xihu Sag.The Paleogene sandstones under the depth of3 500 mare generally in the tight reservoir stage and are the most favourable for the formation of tight sandstone gas reservoir in Xihu Sag.The conditions of source rocks,reservoirs and contact relationship between the two in Xihu Sag are similar with that in Ordos Basin.It is therefore concluded that there are preliminary geological conditions for tight sandstone gas reservoir in Xihu Sag.更多还原