Towards a Reliable Determination of Saturation Pressure: A Hybrid of Mouth Brooding Fish MBF Algorithm and Flash Calculations

Abstract

Abstract Determination of the saturation pressure as one of the most prominent PVT properties of each oil sample has been the topic of many expensive and time-consuming experimental and numerical methods. The current research aims conducting a systematic search procedure to estimate the saturation pressure of an oil sample based on the application of flash calculations tuned with a modern optimization algorithm. The saturation pressure is the only one at which the total product value of Zi (mole fraction of component i in the entire hydrocarbon mixture) by Ki (pressure dependent equilibrium ratio of component i) is equal to the unity. Instead of using a trial-and-error method to compute a pressure which satisfies the abovementioned condition, advantages of metaheuristic algorithms like Mouth Brooding Fish (MBF) can be utilized to evolutionarily find the saturation pressure. The pressure of each cichild has been evaluated based on a cost function which relies on values generated with Equations of States (EOS). The squared difference between the generated output and the unity is the amount of error which has been minimized within the running of the MBF. Whereas the determination of saturation pressure through the application of flash calculations has traditionally been a challenging case in terms of providing a proper initial guess, the proposed procedure has turned the previous method into a systematic, super-fast and programmable trend which can easily be inserted into the commercial packages of reservoir simulations.