松南气田火山岩致密储层分类及有利目标潜力评价

松南气田属于致密火山岩气藏。根据松南气田大量火山岩气井产能测试数据,以气井产能为依据进行分类,并分别统计它们的岩性、密度、声波时差、孔隙度、渗透率、阻抗范围,建立松南气田致密火山岩储层的分类标准。在此基础上,利用岩心、铸体薄片和扫描电镜,识别不同类型储层的宏观、微观孔隙-裂缝组合特征,研究不同类型火山岩储层的孔隙-裂缝发育模式。并进一步根据储层类型、地震反演孔渗参数,探讨了大型火山岩气藏潜力目标区优选方法。松南气田火山岩储层可分为I类未措施高产、II类措施后高产、Ⅲ类未措施不出气、Ⅳ类致密层四类。四类储层对应四种储层发育模式:I类储层为原生孔+微裂缝型,II类储层为次生孔+微裂缝型,Ⅲ类储层为原生孔+构造裂缝型,Ⅳ类储层为次生孔+构造裂缝型。潜力优选研究表明,YS1断块2号、3号目标体具有一定的开发潜力。储层分类更适合于本区致密储层的实际生产情况。

Classification Standard of Dense Volcanic Reservoirs and Potential Evaluation for Exploitation Targets in Songnan Gas Field

The Songnan gas field is mainly composed of compacted volcanic reservoir with low permeability.According to the gas testing results of the Yingcheng Formation,and other data such as porosity,permeability and impedance,a reservoir classification standard was established.Based on the observation of core,thin sections and SEM,developing patterns of vesicle and fissure in four types of reservoirs have been studied.In addition,potential target reservoirs have been described and evaluated.The reservoir in Songnan gas field can be divided into four types:Type Ⅰ is high yield without fracturing operation.Type Ⅱ is high yield after fracturing operation.Type Ⅲ is no yields before fracturing operation.Type Ⅳ is dense layer.Vesicle-fissure pattern corresponding to each reservoir type has been described.Reservoir Ⅰ presents primary vesicle-microfissure reservoir pattern.Reservoir Ⅱ presents secondary vesicle-microfissure reservoir pattern.Reservoir Ⅲ presents primary vesicle-tectonic fissure reservoir pattern.Reservoir Ⅳ presents secondary vesicle-tectonic fissure reservoir pattern.Potential evaluation indicated that the No.2 and No.3 targets in YS1 fault block have great potential for development.This study will benefit the analysis of exploiting potentialities,and the reservoir classification standard is more suitable for the actual production situation of dense volcanic reservoir in this area.