Petroleum Science >2024, Issue3: - DOI: https://doi.org/10.1016/j.petsci.2024.03.018
Supramolecular polymer-based gel fracturing fluid with a double network applied in ultra-deep hydraulic fracturing Open Access
文章信息
作者:Yong-Ping Huang, Yong Hu, Chang-Long Liu, Yi-Ning Wu, Chen-Wei Zou, Li-Yuan Zhang, Ming-Wei Zhao, Cai-Li Dai
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投稿时间:
引用方式:Supramolecular polymer-based gel fracturing fluid with a double network applied in ultra-deep hydraulic fracturing, Petroleum Science, Volume 21, Issue 3, 2024, Pages 1875-1888, https://doi.org/10.1016/j.petsci.2024.03.018.
文章摘要
Abstract: A gel based on polyacrylamide, exhibiting delayed crosslinking characteristics, emerges as the preferred solution for mitigating degradation under conditions of high temperature and extended shear in ultralong wellbores. High viscosity/viscoelasticity of the fracturing fluid was required to maintain excellent proppant suspension properties before gelling. Taking into account both the cost and the potential damage to reservoirs, polymers with lower concentrations and molecular weights are generally preferred. In this work, the supramolecular action was integrated into the polymer, resulting in significant increases in the viscosity and viscoelasticity of the synthesized supramolecular polymer system. The double network gel, which is formed by the combination of the supramolecular polymer system and a small quantity of Zr-crosslinker, effectively resists temperature while minimizing permeability damage to the reservoir. The results indicate that the supramolecular polymer system with a molecular weight of (268–380) × 104 g/mol can achieve the same viscosity and viscoelasticity at 0.4 wt% due to the supramolecular interaction between polymers, compared to the 0.6 wt% traditional polymer (hydrolyzed polyacrylamide, molecular weight of 1078 × 104 g/mol). The supramolecular polymer system possessed excellent proppant suspension properties with a 0.55 cm/min sedimentation rate at 0.4 wt%, whereas the 0.6 wt% traditional polymer had a rate of 0.57 cm/min. In comparison to the traditional gel with a Zr-crosslinker concentration of 0.6 wt% and an elastic modulus of 7.77 Pa, the double network gel with a higher elastic modulus (9.00 Pa) could be formed only at 0.1 wt% Zr-crosslinker, which greatly reduced the amount of residue of the fluid after gel-breaking. The viscosity of the double network gel was 66 mPa s after 2 h shearing, whereas the traditional gel only reached 27 mPa s.
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Keywords: Ultra-deep reservoir; Gel fracturing fluid; Double network; Supramolecular polymer system; Proppant suspension property