高渗油藏聚合物溶液携带弹性微球驱室内实验

Experimental research on polymer carrying elastic micro-spheres flooding in high permeability reservoirs

聚合物驱油技术用于复杂断块高渗油藏注水开发后期提高采收率将面临两个问题:一是聚合物沿高渗透层水淹层过早地窜流;二是在特高含水期聚合物驱的效果会降低。为此研究了在高渗油藏条件下,利用聚合物溶液携带弹性微球的新方法,来增加聚合物溶液在驱油过程中的渗流阻力,进一步扩大波及体积,提高驱油效率。实验研究了弹性微球在油藏条件下的抗温抗盐热稳定性等理化指标,弹性微球在地层温度65℃条件下,60 d内均保持原有现状;聚合物溶液携带微球后,与单纯聚合物溶液驱相比,弹性微球产生的阻力系数为1.5,残余阻力系数为1.2;浓度为1500 mg/L聚合物驱比水驱提高采收率13.5个百分点,浓度为1000 mg/L聚合物+500 mg/L弹性微球后,比水驱提高采收率17.3个百分点,比单纯1000 mg/L聚合物驱采收率增加4.8个百分点,比浓度为1500 mg/L纯聚合物驱采收率增加3.8个百分点。

Two problems were faced when polymer flooding technology was used in complex fault-block high permeability res-ervoir at the stage of later water-flooding for EOR.Firstly,polymer will go along with water flooded layers with high permeability too soon;secondly,the effect of polymer flooding will decrease in ultra-high water cut stage.This paper conducted the new method of polymer carrying elastic microspheres in high porosity high permeability reservoirs,so as to increase percolation resistance,enlarge sweep volume further and enhance oil displacement efficiency.Experimental research on the physicochemical index of heat resistance,salt tolerance and thermal stability in the reservoir condition have done,which found that microspheres kept primary shape at 65 degree during 60 days;the RF and RRF of polymer carrying elastic microspheres were 1.5 and 1.2 respectively;1500 mg/L polymer solution flooding improve oil recovery 13.5 percent compared with water flooding;1000 mg/L polymer combined with 500 mg/L microspheres improve oil recovery 17.3 percent compared with water flooding,and the value of were only 4.8 percent and 3.8 percent respectively compared with 1000 mg/L polymer and 1500 mg/L polymer flooding individuals.