特低渗透储层的应力敏感性研究及应用

Stress Sensitivity Research and Its Application in Extra-low Permeability Reservoirs

针对特低渗透储层开展了敏感性试验,研究储层渗透率随压力的变化规律,探讨了降压开采、超前注水对储层开发效果的影响。结果表明,特低渗透岩心具有较强的应力敏感性,随着有效压力的增大,渗透率急剧降低,且水测渗透率比气测渗透率更低;开展超前注水、把握超前注水时机能获得较高原油采收率;特低渗透储层SP199井区矿场实施超前、同步注水试验,油井产量稳定、递减幅度明显变小,取得显著稳油效果。

A stress sensitivity experiment was made for ultra-low permeability reservoirs in order to investigate the rules of reservoir permeability changes with pressure,and the influence of advanced water injection on reservoir development.The results show that the core from ultra-low permeability reservoir has a strong stress sensitivity,the permeability decreases sharply as the effective pressure increases with the permeability damage more severely of water than that of gas,and advanced water injection at proper time obtains a relatively high oil recovery.The experiments of advanced water injection and synchronous water injection in the ultra-low permeability reservoirs of Well Block SP199 obtain positive results of stable oil production and less production decline rate.