Oil has undeniable importance in modern times. Along with other fossil fuels, represents a considerable portion of the energy matrix of society. However this is non-renewable energy source. As the oil is been produced in areas of easy access, its source is being exhausting and creating the need to explore in inhospitable regions. Looking to this scenario subsea processing of oil and gas has great importance to allow oil production in regions where the production would not be possible without this option. The objective of this study is to compare two subsea processing systems, one with a multiphase pump and other with a separator and a monophase pump, identify opportunities of each system and the current state of the art of each technology. The leap of subsea processing will be a future of production systems without the use of platforms. This scenario already being felt today in some gas fields. The gas field was the first to present the possibility of production without the use of the platform due to the fact that gas fields has enough energy to flow over large distances without the need of artificial lifting. However, with the advancement in pump technology and subsea separators, the future indicates the application of this procedure also in oil fields. This paper provides a simplified calculation tool for multiphase flow of easy access that allows the calculation without the need of advanced commercial software. Despite being a simplified tool is useful for quick calculations.