【摘要】 黏土膨胀或运移/沉积会造成孔隙堵塞或吼道堵塞,从而引起储层孔隙度及渗透率的下降,导致油气井产能降低。提出了利用泡沫解堵技术来解除黏土造成的储层伤害,并设计了氮气泡沫解堵试验系统。为了模拟黏土造成不同程度的储层伤害,以PVA薄膜包裹细粉砂及钙基膨润土的方式,制备了3块可出砂人造岩心。岩心测试结果显示,黏土含量越高,岩心的渗透率越低,说明黏土造成的储层伤害越严重。泡沫解堵试验结果显示,将泡沫注入岩心再放喷,可携带出部分砂土混合物,能够有效解除黏土造成的储层伤害,渗透率恢复速度较快;黏土造成的伤害比由细粉砂造成的储层伤害严重。此研究可为储层伤害修复提供理论依据。更多还原

【Abstract】 Reservoir damage caused by clay is due to clay swelling or transport/deposition,which causes porous media blockage,drop of reservoir porosity and permeability,and reduce of oil and gas well production capacity.Foam plugging technology is proposed in this paper to remove the reservoir damage caused by clay,and cyclic foam stimulation test system is designed.In order to simulate formation damage caused by clay in different levels,3man-made sand producible cores invent firstly based on PVA film wrapped fine sand and calcium bentonite.Experiments results show that more weight percentage of clay in formation will cause lower of core permeability,the reservoir damage more seriously.Foam has good discharge effect on sand blockage and clay swelling.Permeability restitution coefficient is defined;the damage caused by the clay is severer than by the fine sand.更多还原