启动压力测定对吉林油田低渗透油藏开发效果的影响

存在启动压力梯度意味着流体的渗流偏离达西定律,为非线性渗流。通过对吉林油田部分区块的启动压力测定及测试结果分析,得出结论:在低速渗流条件下,流体的流动为非线性渗流;流体在低渗透岩心中渗流时,存在启动压力梯度;启动压力受样品渗透率的影响,相对气测渗透率来说,岩心的渗透率越低,水测和油测渗透率的下降越显著,其启动压力越高;驱替速度对低渗透油藏采收率有较大的影响,有一个最佳的驱替速度。

Effect of measuring start-up pressure on development effectiveness of low-permeability reservoir in Jilin oilfield

The existence of start-up pressure means that the fluid deviates from the Darey's Law,so the fluid is of the non-linear flow in porous media.Through the measuring of start-up pressure and the study on relation between start-up and permeability as well as the flow experiment of water-flooding,it can be concluded that under the low-velocity flow in porous media,the fluid flow is t non-linear;it ex ists the start-up pressure gradient when the fluid seeps through the low-permeability core.It also shows that the start-up pressure is subject to the permeability of samples.Compared with the permeability under gaseous medium,the lower the permeability of core,the larger falling of permea-bility under water medium and oil medium and the higher the start-up pressure.The displacement velocity has a large effect on the recovery rate of low-permeability reservoir and there exists a optimum displacement velocity.