Synthesis and Evaluation of a New Acryloyl-Based Copolymer as Kinetic Hydrate Inhibitor for Sour Gas Environments

Blockage of gas flow lines by gas hydrates is a major problem in the oil and gas industry, which leads to severe safety issues and causes economic losses. Kinetic hydrate inhibitors (KHIs) are water-soluble polymers that are employed to circumvent this problem due to their effectiveness at low dosage, which makes logistics (transport, storage, and pumping) less costly particularly in offshore operations. However, some of the currently available KHI polymers have subcooling constraints against class I hydrates in high sour gas conditions, which limit their utilization. In this Article, we report a new KHI copolymer synthesized from N-acryloyl pyrrolidine and N-acryloyl piperidine monomers. Detailed characterization and compatibility studies were carried out using a variety of techniques and tests. The rocking cell test demonstrated the new formulation's effectiveness to a high subcooling temperature of 8.5 °C at 140 bar of a gas mixture containing a high concentration of CO2 and H2S. The performance of the copolymer was investigated at 2% and 3% dosage, where the increased dosage of copolymer showed a higher subcooling temperature. Collectively, these results set a stage for the design, development, and evaluation of a new type of polymers as an effective KHI.