Synthesis of hydrophobically associating polymer: temperature resistance and salt tolerance properties

In this study, the bifunctional hydrophobic associative polymer of Acrylamide/2‐Acrylamido‐2‐Methylpropane Sulfonic Acid/Lauryl Methacrylate/N,N‐dodecyl Acrylamide (AALD12) with better salt resistance and shear resistance was synthesized by free‐radical micelle polymerization for use as a drag reduction in shale slip water fracturing. In deionized water, the critical associative concentration (CAC) of AALD12 was 0.23%. AALD12 was determined to be theoretically usable for a shale reservoir within 240°C based on its TG study. Microstructure, viscoelasticity, and shear recovery tests show that the polymer has good drag reduction potential and shear resistance. The reduction rates of the polymer AALD12 and the drag reduction agent RSH‐1 in clear water were 77% and 73% (RSH‐1 is a commonly used emulsion‐type drag reduction agent in the market). At the same salt concentration (K+ and Ca2+, 50,000 ppm) and flow rate (40 L/min), AALD12 can maintain a maximum reduction rate of about 63%. The drag reduction rate of RSH‐1 in K+ and Ca2+ solutions can only be maintained at about 52% and 28%, respectively. In the shear resistance test, AALD12 and RSH‐1 were each subjected to three times of cyclic shear in the test pipe. The drag reduction rate of the polymer AALD12 solution can still reach more than 72%. The drag reduction rate of the RSH‐1 solution is about 56%. The drag reduction agent has good salt resistance and anti‐shear bifunction.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preparation and properties research of a bifunctional hydrophobic associative polymer drag reduction agent for slick water

Sun

Zhou

et al. 2023

“…[8][9][10][11][12][13] Moreover, researchers have used hydrophobic associated polyacrylamide (HPAM) instead of PAM to enhance recovery. [14][15][16][17][18][19][20][21][22] HPAM is generally obtained from polyacrylamide grafted with a trace of hydrophobic monomers. The HPAM aqueous solution generally has high viscosity due to the association tendency of hydrophobic interactions.…”

Section: Introductionmentioning

confidence: 99%

“…The interaction between polymer and surfactants may change the properties of the unitary system, which can be used to control the stability, structure, and rheological properties 8–13 . Moreover, researchers have used hydrophobic associated polyacrylamide (HPAM) instead of PAM to enhance recovery 14–22 . HPAM is generally obtained from polyacrylamide grafted with a trace of hydrophobic monomers.…”

Section: Introductionmentioning

confidence: 99%

Reactive carbamate surfactants: Synthesis, characterization, and improved rheological properties of hydrophobically modified polyacrylamide containing surfactant structures

Liu

Lai

et al. 2022

In this study, stearyl alcohol polyoxyethylene ether (AEO) and 2-isocyanatoethyl methacrylate (IEM) are used to synthesize reactive carbamate surfactants (IEM-nAEO), which are characterized through Fourier-transform infrared spectrometry and nuclear magnetic resonance spectroscopy. Additionally, the influence of the AEO-chain content on surface activity is analyzed, and the emulsifying ability of the surfactants is investigated. The surfactants exhibit high surface activities, and their emulsifying abilities enhance upon increasing the AEO-chain content. Additionally, a novel hydrophobically associative polymer is synthesized by copolymerizing IEM-10AEO, acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, and acrylic acid; the rheological properties of its aqueous solution is analyzed. The modified and unmodified polyacrylamide solutions exhibit viscosity retentions of 97.73% and 87.07%, respectively, at 120 C at a shear rate of 170 s À1 . Thus, IEM-10AEO polymerization improves the heat and shear resistance and storage and loss moduli of the polyacrylamide, indicating structural-stability enhancement upon polymerization. Therefore, the modified polyacrylamide can be used to improve the heat and shear resistance of fracturing fluids and enhance oil recovery.

Preparation and performances of a cationic modified polyacrylamide viscosity enhancer for water‐based drilling fluids

Zhang

Wang

Sun

et al. 2023

Polyacrylamide and its derivatives are commonly used as viscosity enhancers in water‐based drilling fluids, but they have limitations in terms of salt resistance and temperature resistance. In this study, a novel cationic functional monomer, 4‐allylaminocarbonyl‐1‐dodecylpyridinium bromide, was introduced into the molecular chains of an acrylamide and acrylic acid copolymer in order to improve its temperature resistance and salt tolerance. Results showed that the apparent viscosity of a 2000 mg/L copolymer solution was 440.4 mPa s at a shear rate of 7.34 s−1, decreasing to 23.5 mPa s at 510 s−1 before recovering to 49.2 mPa s when the shear rate returned to 170 s−1. After 16 h of aging at 120°C, a brine drilling fluid containing 1% of the copolymer showed an apparent viscosity retention rate of 70%, likely due to the formation of a stable net structure between the copolymer's molecular chains and clay particles. These results suggest that the copolymer could be an excellent candidate for use as a viscosity enhancer in drilling fluids.