Core-annular Pattern Research Articles

Energy savings on heavy oil transportation through core annular flow pattern: An experimental approach

The shortage of new light oil reservoirs increases the need to explore heavy oil reserves and to deal with viscosity issues on their transportation through pipelines. An attractive procedure to reduce energy consumption of this operation is to pump oil using water as a wall lubricant in a core annular pattern. This method provides high efficiency and high fluid flow rates, being effective in decreasing pressure drop due to the friction reduction. This paper reports an experimental evaluation of the oil-water flow patterns on three consecutive test sections positioned as the sequence: horizontal vertical horizontal and connected by several hydraulic fittings. Also, photographs were taken to demonstrate the influence of those line irregularities and the directional flow changes on the flow patterns and on the attainable energy savings. The overall energy savings regarding the CAF method presented a factor of 2.2, which means that the same amount of oil could be transported at half the cost. The experiments have also shown that above 50% input oil cuts, no relevant energy reduction in order to compensate higher oil fooling risks was verified.