绒囊流体气藏控水实验研究

Experimental study on water control of fuzzy-ball working fluid in gas reservoir

针对气藏产水问题,利用绒囊流体开展了控水效果评价实验,并结合核磁共振实验技术分析了岩样内部流体分布特征,阐明了绒囊流体在砂岩储层中的控水机理。实验结果表明:绒囊流体具有较好的控水效果,驱替实验中100-2岩样气测渗透率下降了60%,水测渗透率下降了99.1%,岩样100-7驱替过程中受应力作用影响,内部出现了新孔隙,绒囊流体对形成的新孔隙具有自动二次封堵的功能,堵水率可达95.5%。绒囊流体对大孔隙具有较好的封堵作用,对于小孔隙,在注入过程中会在岩石表面形成保护层,避免了工作液进入导致的伤害。绒囊流体具有自然降解的性能,在实际应用中随着时间的推移,实际控水稳气效果会优于室内研究结果。绒囊流体可以有效降低水对气藏的伤害。

In view of the water damage in gas reservoir,the experiment for water control effect is carried out by using fuzzy-ball working fluid,and the distribution characteristics of fluid in rock sample are analyzed by combining with NMR,and the water control mechanism of fuzzy-ball working fluid in sandstone reservoir is clarified.The experimental results show that the fuzzy-ball working fluid has a good water control effect.In the displacement experiment,the gas permeability of 100-2 rock sample decreased by 60%,the water permeability decreased by 99.1%.In the displacement process of 100-7 rock sample,under the influence of stress,new pores appeared inside.The fuzzy-ball working fluid has the function of automatic plugging for the new pores,and the water plugging rate can reach 95.5%.Fuzzy-ball working fluid has good plugging effect on macro-pores.For small pores,a protective layer will be formed on the surface of the rock during the injection process to avoid the damage caused by the entry of working fluid.In practical application,because of natural degradation of fuzzy-ball working fluid,the actual effect of water control will be better than the indoor research results.Fuzzy-ball working fluid can effectively reduce the damage of water to gas reservoir.