To Determine the Efficiency of Wormlike Micelle as Drag Reducing Agent (DRA) for Flow Assurance

In the oil and gas industry, drag reducing agent (DRA) is a necessity for reducing the frictional drag in oil pipeline conduits, oil well operations, and water flooding. DRAs are normally high molecular weight polymers with Polyarcylamide (PAM) as the typical DRA.
However, PAM is permanently mechanically degraded and this could reduce the drag reducing efficiency, giving technical problems to the pipeline and its operation. This paper discusses on the capability of wormlike micelle (WLM) to overcome the mechanical degradation by PAM. Unlike polymeric system, WLMs break and reform when subjected to turbulent flow.
The WLM system is a product of 3-(N,N-Dimethyloctadecylammonia) (TDPS), sodium dodecyl sulphate (SDS), and brine water (0.5M NaCl). The efficiency of WLM as a drag reducing agent (DRA) is done by comparing its performance with PAM. DRA were added to water flowing vertically and horizontally – whereby the pressure drop and flow rate play an important role to quantitatively evaluate their efficiency. The rheological behaviour of DRA, both as a function of viscosity and shear rate, was determined using a viscometer subjected to different surfactant ratios [R=SDS/TDPS], and polymer concentration. The shear thinning phenomenon was also studied.
As a result, WLM gives a higher drag reducing efficiency compared to PAM by 32.80%. This places a significant contribution to the oil distribution through pipelines as it reduces the frictional drag between the fluid and the pipe hence increase the pumpability if liquid. Hence, liquid throughput volume or flow rate is increased as less pressure is needed to push the oil in the pipeline. Pressure drop can be reduced, leading to lower operating expenditure, optimized oil distribution, and longer pipe life.