Open Access

ARTICLE

Application of a Hyperbranched Amide Polymer in High-Temperature Drilling Fluids: Inhibiting Barite Sag and Action Mechanisms

Qiang Sun^1,2,*, Zheng-Song Qiu¹, Tie Geng², Han-Yi Zhong¹, Weili Liu², Yu-Lin Tang², Jin-Cheng Dong²

1 School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, 266580, China
2 China Oilfield Services Ltd., Tianjin, 300459, China

* Corresponding Author: Qiang Sun. Email:

(This article belongs to the Special Issue: Advances in Functional Polymer Composites: Synthesis, Characterization and Applications)

Journal of Polymer Materials 2025, 42(3), 757-772. https://doi.org/10.32604/jpm.2025.069808

Received 01 July 2025; Accepted 20 August 2025; Issue published 30 September 2025

Abstract

Addressing the critical challenges of viscosity loss and barite sag in synthetic-based drilling fluids (SBDFs) under high-temperature, high-pressure (HTHP) conditions, this study innovatively developed a hyperbranched amide polymer (SS-1) through a unique stepwise polycondensation strategy. By integrating dynamic ionic crosslinking for temperature-responsive rheology and rigid aromatic moieties ensuring thermal stability beyond 260°C, SS-1 achieves a molecular-level breakthrough. Performance evaluations demonstrate that adding merely 2.0 wt% SS-1 significantly enhances key properties of 210°C-aged SBDFs: plastic viscosity rises to 45 mPa·s, electrical stability (emulsion voltage) reaches 1426 V, and the sag factor declines to 0.509, outperforming conventional sulfonated polyacrylamide (S-PAM, 0.531) by 4.3%. Mechanistic investigations reveal a trifunctional synergistic anti-sag mechanism involving electrostatic adsorption onto barite surfaces, hyperbranched steric hindrance, and colloid-stabilizing network formation. SS-1 exhibits exceptional HTHP stabilization efficacy, substantially surpassing S-PAM, thereby providing an innovative molecular design strategy and scalable solution for next-generation high-performance drilling fluid stabilizers.

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Keywords

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