Evaluating and designing systems for mixing water in oil
Tutor / director / evaluatorErik Øi, Lars
Document typeBachelor thesis
Rights accessOpen Access
The oil and gas industry includes the processes of exploration, extraction, upgrading, separation, refining, transporting and marketing oil products. After the separation process, water is removed to a great extent, and only a small percentage is left in the crude oil. When marketing the products, the value is essential, and therefore a representative sample has to be extracted to determine the quality. This requires that the water is uniformly distributed throughout the batch when it is evaluated. FMC Technologies requested a mixing system that would be able to achieve a homogeneous flow in a pipeline, for a range of parameters. Because a laminar flow is the most challenging to mix, the parameters which gives the lowest Reynolds number are chosen as a worst case scenario. By literature studies, it is stated that a uniform mixture can be provided by multiple processes. Mechanically agitated vessels, static- and power mixing have been analyzed. The static mixer is evaluated based on the state of the art, and a power mixing system is designed for the worst case parameters. Calculations are performed to be able to evaluate. It is found that mechanically agitated vessels are not recommended for in-line mixing and therefore not evaluated further. Pressure drop is expensive, and this is taken into account when discussing a conclusion. A static mixer is recommended for Reynolds numbers below 2000 and a main pipe diameter below 0.4 m. No mixing is required when the Reynolds number reaches a certain peak where the turbulence in the flow is of a large extent and mixing will happened naturally. Otherwise, power mixing is the suggested method to provide a homogeneous flow.