Design And Flow Field Analysis Of Three-phase Separators

Three-phase separator is one of the most important equipment in the oilfield ground engineering. Separation efficiency improvement of the-phase separator is the emphasis of research, and the inner components affect the separation efficiency greatly. This study simulated the sedimentation mechanism of single oil drop and solid in water by the level set theory. This research designed the basis dimension of three-phase separators by Half-Full method, then simulated the separators by FLUENT software and got the inner fluid transient simulation of the separator which was composed of a kind of different parameters of coalescence structure. The main results are as follows:(1) Half-Full method was used to design the horizontal settling separator. The initiatory size of Half-Full horizontal separator could be calculated by the oil-water settling separation principle, residence time of liquid phase and gas capacity constraints, which provided the size data for simulation. Then the structures of inlet, demister and coalescence structure et al were determined by comparing and analyzing.(2) For the first time, using the level set theory to simulate the sedimentation mechanism of single oil drop and solid in water, the sedimentation mechanism of single oil drop and solid in water was founded by this research. The results show that time and speeds of separation are related to the diameter of oil drop and solid.(3) Two millimeter mesh grid of coalescence structure was chosen by contrasting the simulation accuracy of different mesh parameters. The sedimentation mechanism of was clearly analyzed by comparing the speed, pressure and volume of fraction of exclusive coalescence structure and coalescence structure. The diameter of oil drop has an effect on the separation efficiency, the result presents that the sedimentation separation was difficulty when reduced the diameter of oil drop. Then, water contained oil drop and gas bubble, water contained oil drop and solid particle were analyzed to understand the separation mechanism.(4) The structure of coalescence structure, including angle of inclination and distance between plates, was studied to find out the best parameters which can advance the separation efficiency. The results prove that the coalescence structure may reach the maximum separation efficiency under angle of inclination is 45°, and distance between plates is 15 millimeter. The coalescence structure with holes was researched to confirm whether they can prove the separation efficiency, the results present that the coalescence structure with holes has little influence on separation efficiency.