Synthesis and Performance Evaluation of a High-Temperature-Resistant Plugging and Inhibition Agent

A high-temperature-resistant plugging–inhibitor (DS) was synthesized via emulsion polymerization using styrene (St), butyl acrylate (BA), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), and N-vinylformamide (NVF), with divinylbenzene (DVB) as crosslinker and ammonium persulfate (APS) as the initiator. The structure and properties were characterized by FTIR, TG, SEM, and contact angle analysis. Plugging and inhibition performances were evaluated through filtration, high-temperature high-pressure (HTHP) plugging, linear swelling, and shale recovery tests. DS exhibits spherical morphology with particle sizes of 50–100 nm and a decomposition temperature of ~297 °C, indicating good thermal stability. The addition of DS significantly reduces filtration loss; at 1.5 wt%, the API filtration loss decreases to 6 mL. Under 180 °C conditions, 1 wt% DS reduces HTHP filtration loss from 12 to 6 mL, demonstrating excellent high-temperature plugging performance. DS also effectively suppresses shale hydration, with linear swelling reduced to 1.48 mm and shale recovery increased to 64.68% at 3 wt%. These results indicate that DS possesses excellent thermal stability, plugging efficiency, and inhibition performance, offering a promising solution for wellbore stability in shale gas drilling.