低表面张力滑溜水在低压致密气藏中的应用

Application of Low Surface Tension Slick Water in Low Pressure Tight Gas Reservoir

何定凯

HE Dingkai

低压致密气藏储层渗透率低、孔隙度小、压力系数低，普遍存在因压裂液入侵造成的水敏伤害问题。为了降低压裂液对低压致密气藏储层伤害，提高压裂液返排率，筛选一种配方为 0.15%减阻剂 XY-205+0.1%助排剂XY-120+0.2%防膨剂 XY-63的具有低表面张力的滑溜水体系，并考察了该滑溜水的减阻率、防膨率以及对岩心伤害性能，并进行了现场应用。该滑溜水体系的表面张力为 20.12 mN/m、与煤油间的界面张力为 1.52 mN/m，最大减阻率达到 70.58%，对王府区块 HG-01井岩心的防膨率达到 90%，滑溜水对岩心伤害可降至 14.46%。滑溜水在低压致密气藏现场应用 3口井，压裂施工顺利，压后见气速度快，排液 4 h见气，返排率 61%，取得较好的改造效果。图 2表5参 11

The low pressure tight gas reservoir is characteristic of low permeability，low porosity and low pressure coefficient. The problem of water sensitivity damage caused by fracturing fluid invasion is widespread in the low pressure tight gas reservoir. In order to reduce the damage of fracturing fluid to reservoir and increase the flowback rate of fracturing fluid，the slick water system with low surface tension was selected，composed of 0.15% drag reducer XY-205，0.1% clean up additive XY-120 and 0.2% antiswelling agent XY-63. The drag reducing rate，anti-swelling rate and core damage performance of the slick water were also investigated，and the slick water had been put into field uses. The result showed that the surface tension of the slick water was 20.12 mN/m and the interfacial tension between the slick water system and kerosene was 1.52 mN/m，The drag reduction rate of the slick water system was up to 70.58%，and the antiswelling ratio of the core of HG-01 well in Wangfu block was 90%. The core damage caused by slick water was as low as 14.46%. The application of slick water in 3 wells of low pressure tight gas reservoir showed that the fracturing operation was successful，the gas breakthrough rate was fast after fracturing，the flowback rate of slick water was 61%，and the gas came out after 4 hours of running slick water. The application of low surface tension slick water in low pressure tight gas reservoir had achieved good results.