清洁滑溜水压裂液在长宁H26平台的应用

Application of Clear Slick Water Fracturing Fluid on Changning-H26 Platform

目前使用的滑溜水压裂液存在着与返排水不适应以及对储层伤害大等缺点。根据四川盆地南部下志留统龙马溪组页岩特点及施工需要,研发出一种适合长宁区块的清洁滑溜水压裂液体系,进行了室内性能评价和现场应用。室内实验表明,该压裂液主剂JHFR-2的减阻性能好,使用现场返排液配制滑溜水时减阻率可达70%,溶解时间在30 s以内,最优加量为0.07%~0.10%;对岩心渗透率恢复率为91.9%;压裂液无毒,易返排。在长宁H26-4井的应用表明,清洁滑溜水压裂液的降阻性能好,能达到连续在线混配施工的要求,完全满足长时间大液量大砂量的页岩气井地层压裂。该压裂液配制工艺简单,可降低施工成本,有较好的应用前景。

Slick water fracturing fluids presently in use have some shortages, such as incompatible with the flowback water and severe damage to reservoirs etc. Based on the characteristics of the Longmaxi shales of the Lower Silurian system in the south of the Sichuan Basin and field operational requirements, a clear slick water fracturing fluid has been developed for use in Block Changning. Laboratory evaluation of the slick water fracturing fluid shows that the main additive, JHFR-2, in the fracturing fluid has good drag reducing performance. Slick water formulated with the flowback water and JHFR-2 has drag reducing efficiency of 70%, and it only takes 30 s or shorter time for JHFR-2 to dissolve. The optimum treatment of JHFR-2 is 0.07%-0.10%. Percent permeability recovery of cores flowed with the formulated slick water is 91.9%. The clear slick water fracturing fluid is non-toxic and easy to flow back. Application of the clear slick water fracturing fluid on well H26-4 and well H26-5 proved that the fracturing fluid had good drag reducing performance. Continuous mixing of the slick water fracturing fluid for direct use completely satisfied the needs of long time fracturing of shale gas wells which consumed large volume of fluid and large amount of sands. The easily formulated low cost clear slick water fracturing fluid is believed to have good application prospect.