低渗油藏纳米粉体堵剂性能评价及应用

针对常规无机颗粒堵剂不适合特低渗砂岩油藏卫360块挤堵的问题,对纳米粉体堵剂的性能进行了室内综合评价。密度1.4~1.8 g/cm3堵剂浆体的黏度小于35 m Pa·s,注入性好,能进入地层深部孔隙;悬浮性好,密度大于1.6 g/cm3时,浆体基本不分层;固化时间可调,施工安全,初凝时间2.7~18.5 h,终凝时间3.1~28.1 h;固化后体积不收缩,抗压强度大于25 MPa,封堵率达到99.9%;具有一定的溶解性,渗透率恢复率大于50%。介绍了现场挤堵工艺,掌握挤堵关键环节和精细施工能提高挤堵一次成功率。在低渗油藏卫360块应用27井次,工艺成功率100%,增油有效率100%。纳米堵剂是一种高效新型堵剂,施工安全性好,措施成功率高,对低孔低渗地层具有较好的封堵作用。

Evaluation on performance of nano-powder plugging agent and its application in low-permeability reservoirs

In view of the problem of conventional particulated inorganic plugging agent being not suitable for Wei 360 Block which is a low permeability reservoir, an indoor comprehensive evaluation was conducted on the performance of nano-powder plugging agent. The viscosity of plugging agent fluid with density of 1.4~1.8 g/cm3 is less than 35 mPa·s, so it has good injectivity and can enter deep pores in the formation. It also has favorable suspension property, when its density is greater than 1.6 g/cm3, the fluid does not delaminate. Its curing time can be adjusted and it can be used safely. Its initial setting time is 2.7 h to 18.5 h, and final setting time is 3.1 h to 28.1 h. After being set, its volume will not shrink, its compressive strength is over 25 MPa, and the rate of plugging is up to 99.9%. It has certain solution property, and the recovery rate of permeability is over 50%. This paper introduces the field plugging technology, and knowledge of key plugging points and fine operation can increase the one-time success rate of plugging. This plugging agent has been used in 27 wells in Wei 360 Block of low permeability reservoir, and the technological success rate is 100%, and the effective rate of increase in oil production is 100%. Nano-powder plugging agent is a highly effective new plugging agent with good job safety and high success rate and can effectively seal and plug the low porosity and low-permeability formations.