低渗透油藏超前注水压敏效应实验研究

Experiment study on the pressure-sensitive effects of advanced water injection in low permeability reservoir

将岩心渗透率分为四个级别进行了流体压力对渗透率、孔隙度、孔喉半径和配位数影响的室内实验,结果表明孔隙度对压力变化不敏感,渗透率、孔喉半径和配位数随压力升高只有小幅度上升,而随压力降低有较大幅度下降,由此验证了通过增加孔隙流体压力来恢复储层物性的目的不能实现.因此在造成储层物性损害之前,可通过超前注水来保持较高的地层压力,提高低渗透油田的最终采收率.

The core permeability was divided into four levels for laboratory experiments on the effects of the pore-fluid pressure on permeability,porosity,pore throat radius and coordination number,the results showed that the porosity was insensitive to pressure change,the change rule of pore throat radius and coordination number is similar to that of the permeability:the increasing extent of the three is very small during the pressurizing process,but the decreased degree was increasing obviously of the three during the depressurizing process.According to the experimental result,it is irrealizable to restore the reservoir property by increasing the pore-fluid pressure.Advanced water injection is an important way to enhance the ultimate recovery of low permeability oilfields by maintaining the high formation pressure and reducing the reservoir damage caused by the formation pressure drop.