Thermodynamic Modeling of Wax Deposition Phase Behavior for Reservoir Fluid in Southern Iraqi Oil Field

Mohammed A. Ahmed; Ali A. Rashak; Mohammed  E. Resan

doi:10.52716/jprs.v16i1.1023

Authors

Mohammed A. Ahmed Oil and Gas Engineering Department, University of Technology, Baghdad, Iraq
Ali A. Rashak Oil and Gas Engineering Department, University of Technology, Baghdad, Iraq
Mohammed E. Resan Oil and Gas Engineering Department, University of Technology, Baghdad, Iraq

DOI:

https://doi.org/10.52716/jprs.v16i1.1023

Abstract

Most reservoir fluids contain heavy paraffinic compounds that may precipitate as a solid or solid-like material called wax if the fluid is cooled down. Wax precipitation may cause operational problems when unprocessed well streams are transported in undersea pipelines, in which the temperature may fall to that of the surrounding seawater. Wax may deposit as a solid layer inside the pipeline. With continued transport, this layer will build up and eventually plug the pipeline if not mechanically removed. The need to proactively predict the temperature at which wax will precipitate leads to the development and application of thermodynamic models for such prediction. This study aims to develop a thermodynamic model to predict the wax deposition envelope (WDE), which gives a good idea of the temperature at which wax precipitation occurs. Using a live oil sample from southern Iraqi oilfield, this study used the Soave-Redlich-Kwong (SRK-EOS) model that can predict the specific conditions at which wax precipitation occurs as well as respond to the reservoir fluid. The SRK-EOS results in the Multiflash program were matched with the fluid and wax experimental data. The results pointed out that wax precipitation would happen in tandem with the same production scenario after the temperature dropped.

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