A Review of Drag-Reducing Agents (DRAs) in Petroleum Industry

Increasing the flow capacity and pumping rates is challenging in petroleum production systems due to drag or frictional losses. Drag-reducing agents (DRAs) are usually added to the fluid to reduce the drag and improve the flowing capacity or pumping rates of the fluid required for achieving the targeted flow rate or enhancing transportation efficiency. The wide variation in the oilfield systems demands distinguish features of DRA to meet the specific requirements of the DRA relevant to the oilfield applications. The selection of DRA suitable for the oilfield systems influences the type and formulation of DRA. Oil and gas transportation in the pipeline requires oil-soluble DRA; on the other hand, injection of water requires water-soluble DRA. The requirement of an oilfield system dictates the basic characteristics of the DRA, such as polymer DRA, can be used for transportation of oil and gas; however, the surfactant is preferable for other systems such as drilling and fracturing applications. Also, the recent development in nanotechnology has opened a pathway for the development of DRA for wide application in oilfield systems. This study presents a review of the published work on the DRA applications in the petroleum industry. The methodology and research approaches of drag reduction relevant to oilfield systems are described and analyzed. The experimental work and case studies are also discussed while identifying the research gaps and the recommendations for research approaches and potential areas that need further investigation are highlighted in this study.