Preparation and Performance Evaluation of High-Temperature Resistant Acrylamide/Vinylpyrrolidone Copolymer-Based Gel System

Polymer gels are widely used for profile control and water shutoff in mature reservoirs, while conventional gels are limited under high temperature due to poor thermal stability. This study develops a high-temperature-resistant gel based on acrylamide/vinylpyrrolidone copolymer (P(AM/NVP)), crosslinked with hydroquinone-hexamethylenetetramine (HQ-HMTA). At 150 °C, the gel achieves a Sydansk strength code of H with a gelation time of 9.5 h, and shows excellent thermal stability, maintaining over 90% weight after 180 days. Rheological and microscopic analyses confirm a dense, stable network with high storage modulus (G'). Core flooding tests demonstrate good injectivity with resistance factors of 3.99~129.93, while the plugging rate exceeds 98%. All the experimental results indicate that the P(AM/NVP)-based gel has great potential for water plugging in high temperature oil reservoirs.