MODELING AND SIMULATION OF ARTIFICIAL LIFTING METHODS ON OFFSHORE OIL PLATFORMS

The objective of the following paper is to present a model for the artificial lifting mechanism known generally as gas-lift and a comparison between its correlates. The comparison between lifting mechanisms can be performed directly, through experiments, or indirectly, through computational simulation. It has been chosen to develop a closer to the state-of-the-art model for the gas-lift, in order to compare it with the results of the multiphase pump simulation contained in the bibliography and included in this paper. Initially a flow pattern has been established, so that the boundary conditions would be known and the control volume would be therefore established as well; in which the intrinsic equations of the flow could be applied. Then, simplifying and adequate hypothesis were formulated, and the geometry, of the high depth riser, in which the mechanism would be simulated, was created, these were inputted into a numerical simulation CFD software. Inputting these geometrical and fluid data along with several controlling equations in the CFX (R) 5.7 software demonstrated the behavior of the gas lift, both in the transient, as an illustration, and in the steady state flow, and permitted an evaluation and graphical analysis of relevant parameters of the gas lift mechanism. Finally a comparison, between the results obtained by the SMPS (Submarine Multiphase Pumping System) and the above has been performed, showing in which situations the mechanisms presented a higher performance in a real high depth offshore well located in the Campos Basin, Rio de Janeiro.