Preparation of Fracturing Fluids With Viscoelastic Surfactants and Its Adsorption/Desorption Properties on Shale Gas
-
摘要: 针对传统的羟丙基胍胶(HPG)压裂液携砂能力差、破胶后残渣多、对储层伤害大等难题,合成了一种两性离子表面活性剂—芥酸酰胺丙基羟基磺基甜菜碱(EAPHS),通过优化与反离子盐水杨酸钠的配比,制备了黏弹性表面活性剂(VES)压裂液体系。VES压裂液体系在120℃、170 s−1条件下恒定剪切60 min后的黏度为34 mPa·s,具有优异的抗剪切性能,体系的减阻效率为63.1%,对岩心的损害率仅为7.34%,表明VES压裂液体系具有较好的储层保护效果,能够有效减少压裂后对储层的二次伤害。经过VES压裂液处理后,岩心的微裂隙增多且孔隙连通性增强,岩心表面的润湿性由亲油表面反转为亲水表面,岩心的氮气吸附量、比表面积和孔隙体积均增大,有利于甲烷的解吸和开采,同等平衡压力条件下,VES压裂液处理后的甲烷解吸量显著增加。VES压裂液体系在四川盆地宁页X-1井进行了现场应用,施工过程中压力平稳,产气率提高了15%以上,取得了较好的应用效果。这一研究为后续VES压裂液体系的构筑及对页岩气的高效开发提供了指导和参考价值。Abstract: Aiming at the problems of poor sand-carrying capacity, high residue after breaking the hydroxypropyl guanidine gel (HPG) fracturing fluid, and great damage to the reservoir, an Zwitterionic surfactant, erucic acid amidopropyl hydroxysulfobetaine (EAPHS), was synthesized, and a Viscoelastic Surfactant (VES) system was prepared by optimizing the ratio of the VES system to the counter-ionic salt, sodium salicylate (NaSal). The viscosity of the VES fracturing fluid system was 34 mPa-s after constant shear for 60 min at 120℃ and 170 s−1, with excellent anti-shear performance, the drag reduction efficiency of the system was 63.1%, and the damage rate to the core was only 7.34%, which indicated that the VES fracturing fluid system had a better reservoir protection effect, and was able to effectively reduce the secondary damage to the reservoir after fracturing. It shows that the VES fracturing fluid system has good reservoir protection effect and can effectively reduce the secondary damage to the reservoir after fracturing. After VES fracturing fluid treatment, the microfractures of the core increased and the pore connectivity was enhanced, the wettability of the core surface was reversed from oleophilic to hydrophilic, and the nitrogen adsorption, specific surface area and pore volume of the core increased, which is conducive to methane desorption and exploitation, and under the same equilibrium pressure conditions, the methane desorption volume increased significantly after VES fracturing fluid treatment. The VES fracturing fluid system was applied in the field of Ningye X-1 well in the Sichuan Basin, and the pressure was smooth during the construction process, and the gas production rate was increased by more than 15%, which achieved better application results. This study provides guidance and reference value for the subsequent construction of VES fracturing fluid system and the efficient development of shale gas.
-
表 1 VES压裂液体系中的支撑剂沉降速度
压裂液
类型T/
℃沉降高度/
mm沉降时间/
s沉降速率/
mm·s−1VES 70 152 864 0.18 80 150 535 0.28 90 148 462 0.32 AVES-1 70 150 608 0.25 80 149 317 0.47 90 152 194 0.78 HPG 70 153 78 1.96 80 151 50 3.02 90 149 25 5.96 表 2 VES压裂液和HPG压裂液体系的岩心损害性能评价
岩心编号 长度/mm 直径/mm 压裂液类型 K0/mD Kd/mD 损害率/% C1 50.48 2.52 VES 0.627 0.581 7.34 C2 50.55 2.54 HPG 0.648 0.435 32.87 C3 50.24 2.51 AVES-1 0.685 0.592 13.58 -
[1] JIANG G C, SUN J S, HE Y B, et al. Novel water-based drilling and completion fluid technology to improve wellbore quality during drilling and protect unconventional reservoirs[J]. Engineering, 2022, 18: 129-142. doi: 10.1016/j.eng.2021.11.014 [2] 何骁, 陈更生, 吴建发, 等. 四川盆地南部地区深层页岩气勘探开发新进展与挑战[J]. 天然气工业, 2022, 42(8): 24-34.HE Xiao, CHEN Gengsheng, WU Jianfa, et al. Deep shale gas exploration and development in the southern Sichuan basin: new progress and challenges[J]. Natural Gas Industry, 2022, 42(8): 24-34. [3] 孙金声, 许成元, 康毅力, 等. 页岩储层钻井液-压裂液复合损害机理及保护对策[J]. 石油勘探与开发, 2024, 51(2): 380-388. doi: 10.1016/S1876-3804(24)60030-3SUN Jinsheng, XU Chengyuan, KANG Yili, et al. Formation damage mechanism and control strategy of the compound function of drilling fluid and fracturing fluid in shale reservoirs[J]. Petroleum Exploration and Development, 2024, 51(2): 380-388. doi: 10.1016/S1876-3804(24)60030-3 [4] HUANG Q M, LIU S M, CHENG W M, et al. Fracture permeability damage and recovery behaviors with fracturing fluid treatment of coal: an experimental study[J]. Fuel, 2020, 282: 118809. doi: 10.1016/j.fuel.2020.118809 [5] YANG S C, YU W C, ZHAO M W, et al. A review of weak gel fracturing fluids for deep shale gas reservoirs[J]. GELS, 2024, 10(5): 345. doi: 10.3390/gels10050345 [6] 罗炎生, 方波, 卢拥军, 等. 耐高温压裂液研究进展[J]. 油田化学, 2018, 35(3): 545-549.LUO Yansheng, FANG Bo, LU Yongjun, et al. Research progress of high temperature fracturing fluid[J]. Oilfield Chemistry, 2018, 35(3): 545-549. [7] BARATI R, LIANG J T. A review of fracturing fluid systems used for hydraulic fracturing of oil and gas wells[J]. Journal of Applied Polymer Science, 2014, 131(16): 40735. doi: 10.1002/app.40735 [8] YANG M M, LU Y Y, GE Z L, et al. Viscoelastic surfactant fracturing fluids for use in coal seams: effects of surfactant composition and formulation[J]. Chemical Engineering Science, 2020, 215: 115370. doi: 10.1016/j.ces.2019.115370 [9] MAO J C, HUANG Z G, CUN M, et al. Effect of spacer hydroxyl number on the performance of Gemini cationic viscoelastic surfactant for fracturing fluids[J]. Journal of Molecular Liquids, 2022, 346: 117889. doi: 10.1016/j.molliq.2021.117889 [10] 潘一, 王瞳煜, 杨双春, 等. 黏弹性表面活性剂压裂液的研究与应用进展[J]. 化工进展, 2018, 37(4): 1566-1574.PAN Yi, WANG Tongyu, YANG Shuangchun, et al. Progress in research and application of viscoelastic surfactant fracturing fluid[J]. Chemical Industry and Engineering Progress, 2018, 37(4): 1566-1574. [11] 姚红生. 南川地区浅层常压页岩气吸附解吸机理与开发实践[J]. 天然气工业, 2024, 44(2): 14-22.YAO Hongsheng. Adsorption and desorption mechanism and development practice of shallow normal pressure shale gas in Nanchuan area[J]. Natural Gas Industry, 2024, 44(2): 14-22. [12] LIU Z H, BAI B J, WANG Y L, et al. Experimental study of friction reducer effect on dynamic and isotherm of methane desorption on Longmaxi shale[J]. Fuel, 2021, 288: 119733. doi: 10.1016/j.fuel.2020.119733 [13] 熊健. 页岩对甲烷吸附性能影响因素研究[D]. 成都: 西南石油大学, 2015.XIONG Jian. Investigation of the influences of the methane adsorption capacity on the shales[D]. Chengdu: Southwest Petroleum University, 2015. [14] HUANG S M, JIANG G C, GUO C P, et al. Experimental study of adsorption/desorption and enhanced recovery of shale oil and gas by zwitterionic surfactants[J]. Chemical Engineering Journal, 2024, 487: 150628. doi: 10.1016/j.cej.2024.150628 [15] 刘川东, 张孝强, 晏佳欣, 等. 聚/表型复合压裂液性能及其对煤样甲烷吸附解吸特性影响实验研究[J]. 中国安全生产科学技术, 2024, 20(3): 32-39.LIU Chuandong, ZHANG Xiaoqiang, YAN Jiaxin, et al. Experimental study on performance of polymer/surfactant type composite fracturing fluid and its influence on methane adsorption and desorption characteristics of coal samples[J]. Journal of Safety Science and Technology, 2024, 20(3): 32-39. -
下载: