长8超低渗透储层压力传播与合理井网形式研究

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450～500m,合理排距范围110～130m;裂缝型储层部署矩形井网(行列式),合理井距范围400～450m,合理排距范围130～150m。

Pressure propagation of ultra-low permeability reservoir and resonable well pattern research of Chang 8 formation

Chang 8 formation of Zhenjing oilfield belongs to low porosity and ultra-low peameability reservoir, and in accordance with reservoir classification standard, it can be classified into pore type and fracture type reservoirs. In order to make a study on the matching relationship between pressure propagation and well pattern of different reservoir types, the analysis of typical oil well dynamic index has been carried out, and then the reservoir pressure propagation characteristics and resonable well pattern for different types have been determined. With integrated application of vector well pattern and numerical simulation methods towards different wells, the plan has been predicted so as to determine resonable well spacing. The results show in pore type reservoir, oil wells have the characteristics of low initial production, quick decline, low pressure propagation, and the injection ability of a injector decreases with the increase of water injection volume, while in fracture type reservoir, the producing wells have the characteristics of high initial production, slow decline, strong water absorbing capacity and the water injectivity index has obvious inflection point. Therefore, in pore type reservoir, diamond back nine o ’clock pattern is deployed with reasonable well spacing range of 450～500 m. In fracture type reservoir, rectangular pattern (determinant) is deployed with reasonable well spacing range of 130～150 m.