ABSTRACT:

In the frame of new technologies for artificial lifting of hydrocarbon streams, a relevant place has been recently taken by multiphase jet pumps. These systems are characterised by a relative simplicity of structural design, absence of moving parts and small dimensions, which provide easy installation and management procedures during fields operations, coupled with an high degree of reliability and very low cost of installation, compared with other boosting systems. These capabilities have a cost to be paid, due to the complexity of fluid dynamic design, because multiphase streams are expected to be driven into this system. The high velocities and the large pressure drops needed for an efficient use of multiphase jet pump, give significant modelling problems both on the physical side and in the numerical solution of the system equations, and finally the results are very sensitive to stream properties, which rapidly change during the stream evolution inside the machine. Moreover, pipeline transients can have a noticeable impact on the jet pump performances, especially if slow hydrodynamic instabilities (i.e. hydrodynamic slug) takes place into the line where the jet pump is installed. The paper presents a complete model of multiphase jet pump, coupled with a simplified steady state simulator of a reservoir/well system. The model has been validated using several measured data coming from real jet pump applications in Italy and abroad. Various operational conditions can be simulated, providing either imposed well performances or reservoir characteristics. The model average error, for all the considered conditions, is below 20% of the measured jet pump performance, identified by the amount of flow which can be sucked by the system for given boundary conditions. Together with the validation results, a case study will be presented, where the model has been used to evaluate optimum sizing for a given set of operational conditions, as an example of the use of the simulation model for real field applications.

This content is only available via PDF.
You can access this article if you purchase or spend a download.