A review: Supramolecular polymers used in high-temperature fracturing fluids research status and prospects on the coupling relationship between molecular conformation and temperature resistance mechanism

Hydraulic fracturing technology, as a crucial method for enhancing oil recovery, has consistently garnered attention and research within the oil and gas industry. As exploration and development of oil fields extend to unconventional deep and ultra-deep reservoirs, there is an increased demand for the high-temperature resistance of fracturing working fluid (fracturing fluids). Traditional natural plant gums and partially hydrolyzed polyacrylamide polymers are progressively inadequate for applications in ultra-high temperature reservoirs. Over the past few decades, supramolecular structures have been incorporated into fracturing fluids, forming complex non- covalent networks through hydrogen bonding, electrostatic attraction, and hydrophobic association to meet the requirements of fracturing fluids in various harsh environments. This paper primarily reviews the types and mechanisms of supramolecular interactions and the current application status of supramolecular polymers in high-temperature fracturing fluids. Subsequently, the paper elucidates the conformation characteristics of high- temperature-resistant supramolecular polymers and discusses their prospects and directions in fracturing reservoirs at temperatures exceeding 200 degrees C. Finally, the key issues to be considered when constructing supra- molecular polymer conformations for ultra-high temperature deep well fracturing fluids were summarized. This review provides a theoretical reference for developing materials resistant to ultra-high temperatures in fracturing.