multi-phase flow

The fluid produced from oil and gas wells is usually two-phase, which due to the need to maximize the efficiency of two-phase separators, achieving accurate design of separator dimensions is essential. But one of the main problems in the country is the impossibility of accurate design of the dimensions of industrial two-phase separators. Therefore, one of the most important issues in the field of oil and gas industry is to achieve a reliable way to design the dimensions of separators that have the best operational efficiency in the process of separating the production fluid. In this study, a review of classical methods of designing two-phase separators based on theoretical and semi-experimental methods was performed. Then, in order to evaluate the two-phase separators in the laboratory, the laboratory pilot design of the separators was performed. Therefore, one of the main problems in this field, namely the lack of a suitable laboratory pilot to experimentally evaluate the performance of two-phase separators, was solved, and it was possible to determine the standard dimensions for accurate design of industrial separators. According to the results of experiments performed in different operating conditions and comparison with the classical design, a correction factor (α) was proposed to modify the classical relations. Finally, the dimensional analysis method was introduced to design the dimensions of the industrial separator using laboratory results. In order to validate the dimensional analysis method, standard dimensions for separating liquid droplets larger than 750μm in the produced fluid by one of the wells in South Pars field were presented and compared with the actual separator dimensions. It should be noted that the design error of industrial separator dimensions compared to the dimensions of separators used in industry, has been less than 4 percent.

Gravity multiphase separators are one of the most important equipment in different industries. Due to the limitations related to semi-empirical models and the high-performance cost of experimental tests in finding the optimized design, computational fluid dynamics (CFD) has been widely used recently. In this research, after a total review on gravity separators, a review of CFD studies on these apparatuses, to find the appropriate model for simulation and optimization, are considered. Results show that, although CFD is a powerful technique for modeling and improving the separator design, some disadvantages like using incorrect models, simplified assumptions and inappropriate optimization methods lead to inaccurate simulation and optimization results, which should be considered in future works.

 A multiphase flow meter is designed to measure the flow rate of two or more phases without phaseseparation.The flow meter must be accurate enough for the desired application. It must be capable to measure the specifications throughout phase fraction of each phase, independent of the flow regime. Various factors are effective on selection of the flowmeter. Moreover, various procedures are present for measurement of multi-phase flows. In this study, a comprehensive review has been implemented on various technologies in multi-phase flowmeasurement in oil industry and the basis of various measurement techniques has been investigated. The advantages, requirements, and constraints of each technology have been reviewed. Finally,the recent advances in this field have been provided for the researchers.