The reservoir characteristics of a subsea oil and gas field are varying over the field life. Several parameters such as composition, liquid and gas fractions and other physical and chemical properties may change. Moreover, specific threats affecting flow assurance and integrity of subsea transport networks are related to the fluid composition. The knowledge of fluid properties is therefore essential, first to design the subsea assets for hydrocarbons transport and subsequently to optimize the production and tune the Production Management System or the next "digital twins" system. Current subsea sampling systems usually do not perform "in situ" subsea measurements on fluid sample. This paper describes an innovative design for subsea sampling leveraging the benefits from subsea all electric and digitalization technologies and enabling a set of measurements on the sampled fluid directly subsea. Within the first development phase, an effort has been spent to understand how advanced chemical and physical analysis can be furtherly performed in situ subsea, by exploiting the microfluidic technology that needs to be tailored to the subsea production of hydrocarbons. Additional subsea sensors can be also added to provide flow measurements for each well. The calculated uncertainties are in line with the standard subsea flowmeters. It is estimated that the cost of this system will be cheaper than the flowmeters available in the market. The conceived system is a combination of few subsea modules, each with specific functions, that can be interconnected in different ways to suit various Operator's requirements and production field, either green or brown. The sampling and measurement operations can be performed either by the modules resident subsea or temporary carried by subsea vehicles. Most of the concepts are patent pending.
Subsea Production Systems are becoming more and more complex and the market is proposing new technologies, often born for other applications, which can be effectively used for the real time monitoring of subsea production systems during subsea field production phase. An important task of monitoring is related to the collection of data on process parameters useful to provide periodic calibration and tuning of Production Management Systems, of multiphase flowmeters or virtual flow meters and other flow assurance predictive tools.
