DISSOLVING AND TESTING OF DRAG REDUCING HIGH MOLECULAR WEIGHT POLYMERS

 Throughput increase by drag-reducing additives offers a suitable quick solution to meet increased demand by pipelining of oil or water which arises either permanently or seasonally. This has placed increased emphasis upon studies directed towards preparing efficient solutions of drag- reducer additives. Commercially available polyisobutylenes (Oppanol B types) of three different high molecular weights in addition to water soluble carboxymethylcellouse were chosen for the investigation. Five locally produced, different oil products, namely light naphtha, heavy naphtha,reformate, special spirit  and xylene mixture, were tested as solvents for polyisobutylene polymers.It was found that reformate was considered the best solvent for Oppanol B type polymers. Homogenous and effective 2 wt. % polymeric solutions were obtained at room temperature by using a shaker for one to three days according to their molecular weight. A homogenous 4 wt. % CMC solution in water was prepared after one day of shaking.Drag reduction efficiency of polyisobutylenes with three different molecular weights (2.6*106 g/mole, 4.1*106g/mole and 5.9*10 g/mole) were tested as a function of polymer concentration and flow rate in a gas oil turbulent flow produced in a gear pump. It was observed that the additive effectiveness was a function of concentration, Reynolds number (turbulence)and the molecular weight of the polymer. Oppanol B 250 of 5.9*10  g/mole molecular weight is the most effective additive.Friction factor was calculated from the experimental data. For untreated gas oil, friction factor values lie near Blasuis asymptote. While, by the addition of polymers into the flow, the friction values are positioned towards Virk asymptote.Carboxymethylecellouse shows a lower effectiveness as a drag-reducer by pipelining of water. This probably due to its lower molecular weight and
its molecular structure compared with Oppanol B polymers of high molecular weight and linear, flexible structure.