室内注气方式对鄯善低渗油藏驱油的影响

针对低渗、特低渗油藏注气段塞大小不同，提高采收率的效果也不同的问题，通过长岩芯驱替实验研究了鄯善低渗油藏水驱后烃气连续驱以及水驱后注0.3HCPV、0.6HCPV烃气后再水驱三种注气段塞大小提高驱油效率的效果。研究结果表明，水驱后注0.3HCPV烃气再水驱气突破时间相对稍早，而水驱后连续注气与水驱后注0.6HCPV烃气再水驱气突破时间较接近；水驱后连续注气气油比远高于水驱后注0.3HCPV、0.6HCPV烃气再水驱的情况，而注0.6HCPV烃气再水驱的气油比又高于仅注0.3HCPV烃气再水驱；水驱后注0.3HCPV、0.6HCPV段塞烃气后再水驱时分别在水驱基础上提高驱油效率6.41%和13.61%，水驱后连续注烃气可在0.6HCPV注气量基础上驱油效率增加0.79%，增幅不大，说明注入0.6HCPV是合适的注入量。

INFLUENCE OF GAS INJECTION WAY ON OIL DISPLACEMENT EFFICIENCY OF SHAN-SHAN LOW PERMEABILITY RESERVOIR IN LABORATORY

Gas injection is an effective way to increase oil recovery in low permeability reservoir,especially in ultra-low permeability reservoir.But if the sizes of gas injection slug are different,the effects of enhanced oil recovery are also different.The authors of this paper study the influence of three sizes of gas injection slug for enhanced oil recovery on Shanshan low permeability reservoir.There are associated gas flooding after water flooding,0.3HCPV associated gas is injected after water flooding then water flooding adopted again and 0.6HCPV associated gas injected after water flooding then water flooding adopted again respectively.The results show that the breakthrough time is earlier in the second step than in the first and third steps,however the breakthrough time in the first and third steps are similar,the GOR under the first condition is much higher than that under the second and third conditions,and the GOR under the condition of re-injected 0.6HCPV associated gas after water flooding is higher than that under the condition only re-injected 0.3HCPV associated gas injection after water flooding;the displacement efficiency are 6.41% and 13.61% respectively under the second and third conditions.The oil recovery ratio of continuous associated gas injection after water flooding increase by 0.79% on the basis of re-injected 0.6HCPV associated gas after water flooding.But the increase is only modest,so the 0.6HCPV injection is the appropriate amount.