高效防膨抗盐滑溜水压裂液体系研究

Study on A Highly Efficient Anti-Swelling and Salt-Resistant Slickwater Fracturing Fluid System

基于某油田配液污水,开展了高效防膨抗盐滑溜水压裂液体系研究,用于解决黏土含量高、强水敏、弱胶结、易松散储层与压裂液体系接触后水化膨胀甚至岩石骨架垮塌堵塞压裂裂缝及基质孔隙、喉道等问题。实验结果表明,以KY-2为抗盐减阻剂、FP-3为有机胺复合防膨剂、ZP-2为助排剂,采用矿化度为15548.96 mg/L的配液污水配制0.05%KY-2+0.4%FP-3+0.1%ZP-2高效防膨抗盐滑溜水压裂液体系,其防膨率(96.2%)可与4%KCl相当,防膨效果好;清水冲洗10次后,防膨率仍有89.87%,长效防膨效果好;同时,在该配液污水条件下,减阻率达78.45%,降阻效果好。通过现场试验效果验证,该体系改善了强水敏储层KCl用量大,成本高,无法使用免混配工艺以及由于高矿化度导致减阻率下降的问题。

A study on a highly-efficient anti-swelling and salt-resistant slickwater fracturing fluid system was conducted based on the wastewater from fluid preparation in an oilfield.This study was designed to solve the blockage problem of induced fractures and matrix pores and throats due to the hydration expansion and even rock skeleton collapse after fracturing fluid system contacts a readily loose reservoir with high clay content,strong water sensitivity,and weak cementation.The experimental results show that a highly efficient anti-swelling and salt-resistant slick water fracturing fluid system prepared from 0.05%KY-2(salt-resistant drag reducer),0.4%FP-3(organic amine compound anti-swelling agent),0.1%ZP-2(cleanup additive),and the said waste water with a TDS of 15548.96 mg/L has an anti-swelling rate(96.2%)equivalent to 4%KCl,which means a satisfactory anti-swelling performance.After washing with tap-water for 10 times,the anti-swelling rate is still as high as 89.87%,which means a satisfactory long-acting antiswelling performance.Besides,with a drag reduction rate of 78.45%,this system has a satisfactory drag reduction performance.Field test results have validated that the new system can effectively alleviate the problems of high KCl consumption,high cost,and inability to use mixing-free process in strong water-sensitive reservoirs,as well as the decrease in drag reduction rate due to high TDS.