长8超低渗透储层压力传播与井网匹配关系研究

The Relationship between Pressure Transmission and Well Pattern in Chang8 Super-Low Permeability Reservoir

镇泾油田长8储层属于低孔超低渗储层,依据储层分类标准在平面上可划分为孔隙型和裂缝型。为了研究不同类型储层压力传播与井网匹配关系,对长8油藏典型油水井动态指标进行分析,给出不同类型储层压力传播特征和合理井网形式。综合应用矢量井网和数值模拟方法对不同井排距方案进行预测,确定合理井排距。研究结果表明,孔隙型储层油井初产低、递减快、压力传播慢、传播范围小;注水井吸水能力随注水量增加而降低。裂缝型储层采油井初产高、递减慢、注水井吸水能力强、吸水指数存在明显拐点。孔隙型储层中部署菱形反九点井网,合理井距范围450～500 m,合理排距范围110～130 m;裂缝型储层部署矩形井网(行列式),合理井距范围400～450 m,合理排距范围130～150 m。

The Chang8 low-porosity and super-low permeability reservoir can be classified to pore-type and fracture-type reservoir based on the reservoir evaluation standard.The actual well performances were analyzed to study the relationship between the pressure transmission characteristics and the well patterns.The pressure transmission characteristics and the optical well pattern of different types of reservoir were gained;the reservoir numerical simulation which considered vector well pattern was performed to identify the optical well and row spacing.The research shows that the relatively low oil production in the pore-type reservoir decreases sharply,the pressure transmission speed and region are small;the water injection decreases with the increase of cumulative water injection.On the contrary,the high oil production in the fracture-type reservoir decreases slowly,the pressure transmission speed and region are huge.The injection well with a obvious inflexion in the water absorption curve has a relatively high water injection.Diamond-shape inverted nine-spot well pattern is suitable to the pore-type reservoir,and the optical well spacing is 450-500m,the optical row spacing is 110-130m.The row-column-type rectangular pattern is suitable to the fracture-type reservoir,and the optical well spacing is 400-450m,the optical row spacing is 130-150m.