Hydrate Antiagglomerants Performance by Characterizing Particle Size Distribution In Situ Flow Condition

Hydrate slurry technology is recognized as one of the suitable methods to solve hydrate blockage problems in deepwater field exploitation and development. The key to applying this technology is to inject high-performance hydrate antiagglomerants (AAs) to prevent hydrate particle agglomeration and ensure fluid flow under good flowable conditions. It is better to evaluate the performance of AAs by field tests; however, effective measurements in the laboratory should be carried out before their industrial application. In this work, the performance of AAs was evaluated by particle size distribution data measured in situ by focused beam reflectance measurement (FBRM) from a high-pressure hydrate slurry flow loop under flow conditions, including unweighted mean particle chord length, square weighted mean particle chord length, and count-based chord length distribution (CLD). Meanwhile, a macroscopic index named effective antiagglomerant time was proposed to combine microscopic particle data to evaluate the performance of AAs. The effects of water content, water bath temperature, and AA dosage on the performance of AAs were studied. The results showed that the unweighted mean particle chord length showing the fine particle information changed slightly according to different experimental conditions, while the squared weighted mean particle chord length displaying the large particle status increased with an increase in the water content as well as a decrease in water bath temperature and AAs dosage, resulting in an upward shifting of count-based CLD, a reduced effective antiagglomeration time, and a weakened performance of AAs. The performance mechanisms of AAs affected by water content, water bath temperature, and AA dosage were addressed. These findings provided a valuable reference for promoting the application of hydrate slurry technology to ensure the safety of multiphase flow pipelines by using AAs under suitable conditions with effective and high performance.