Separator Internal Design Optimization to Enhance the Separation Efficiency of Horizontal Separator by Using CFD

Efficient and effective production fluid separation is required for a success of many production operations. Most of major producers of oil and gas faced the difficulty regarding the production fluid separation equipment known as separator. The separator does not perform 100% efficiency which leads to the uneconomical production of fluid. One of the reasons for this problem to happen, is the separator internal (inlet and baffle perforated plate) does not control the flow uniformity very well. Therefore the optimization of the separator internal is needed in order to meet the required separation process. Different types of inlet designs and type baffle designs were proposed to optimize the separation efficiency in this project. The design proposed based on the engineering point of view and to improve the existing design. The Resak field data were used as a case study for this project. The Computational Fluid Dynamics (CFD) method is used in optimizing the separator internal for better separation efficiency. In applying this method there are several step that have to be done to ensure the simulations are correct. The first step is by doing the meshing validation study. This study is to determine the minimum size of mesh to produce the most accurate result. From the research, for a three meter horizontal separator, the minimum size of mesh that must be used for meshing generation part is 0.02m. This is the critical size of mesh to get the most accurate result. Then move on to the second step in which the model validation of CFD modeling. In CFD modeling there are many fluid models that need to be chosen with respect to the purpose of modeling. For model validation, the CFD modeling of the separator is by duplicating the experimental work from the previous researchers. From the research for the horizontal separator, the fluid model that appropriate to the horizontal separator modeling is Multiphase model (Free surface model) and turbulent model (k-epsilon) with a value of turbulent Schmidt number is 35. In selection of improve inlet design, Inlet design 4 shows the highest separation efficiency which is 99.56%. This is because the structure of the inlet design decreases the velocity of fluid which makes the separation process easier to happen. The large surface area in contact with the fluid at the end of inlet design and the present of porous plate give the advantages to inlet design 4 to reduce the velocity as much as possible. On the other hand, in the analysis of baffle improvement, baffle design 2 shows the improvement in term of separation efficiency. The improvement
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by 1.81% efficiency from the baffle design 1 as the curvy baffle (Baffle Design 2) is more effective in stabilize the flow to reduce the fluid velocity compared to common vertical baffle (Baffle Design 1).