Experimental Study on the Potential of Polymeric Drilling Fluid Additives as Hydrate Anti-Agglomerants by Using Rocking Cell

Gas hydrate is a type of ice like crystals, which could widely form and plug the offshore oil and gas pipelines. In order to reduce the cost of hydrate control in oil and gas transportation, search for new anti-agglomerates (AAs) is always needed. In this work, fourteen different types of polymers from drilling fluid additives were selected and their anti-agglomeration ability on gas hydrate was experimentally studied by using a high-pressure rocking cell. The hydrate volume percentage, slider moving range, and moving velocity were measured for evaluation. Two polymers [acrylamide polymer (AAP) and hydrolyzed polyacrylonitrile ammonium salt (HAPS)] were found to be effective to avoid agglomerating at low hydrate concentration (<= 6%). AAP and HAPS could prevent plugging, while the hydrate concentration is lower than 15.12% and 16.92%, respectively. It was speculated that the hydrogen bonding capability of the hydrophilic groups, the length of the hydrophobic chains and polymer molecules, and the antagonism of different functional groups might affect the anti-agglomerating performance of polymers.

Automated summary

Gas hydrate, an ice-like crystal, can plug offshore oil and gas pipelines. This study focuses on finding new anti-agglomerates to reduce the cost of hydrate control. Fourteen different polymers were selected and experimentally tested for their ability to prevent agglomeration of gas hydrate. The results show that two of the polymers are effective in preventing plugging at low hydrate concentrations.