Document Type : Regular Article


1 University of Technology-Iraq.

2 University of Baghdad, IRAQ

3 Ministry of Oil-Iraq


Asphaltene precipitation and deposition have a detrimental influence on a variety of oil and gas activities, including oil recovery, oil transportation, and petroleum processing. Modeling and predicting phase behavior and asphaltene precipitation are crucial since the Halfaya oil field is still in the early stages of development. Because of the significant expense of remediating asphaltene deposition in crude oil production and processing, screening techniques for assessing the stability of asphaltenes in crude oil have been developed. In this work, the Asphaltene-Resin Ratio, the Colloidal Stability Index, and the Modified Colloidal instability Index are utilized to predict the stability of asphaltene in crude oil. These techniques, as well as the experimental data derived from them, are described in detail. The parameters that control asphaltene precipitation vary from well to well, from high-pressure, high-temperature reservoirs to surface conditions, and must be investigated on an individual basis. Using Multiflash software, this study created a thermodynamic model for bottom-hole crude oil samples from a well in the Halfaya oil field/Nahr-Umr formation. Compositional analysis, PVT data, and reservoir conditions were among the data. The Cubic-Plus Association equation of state was used to develop a thermodynamic model of asphaltene phase behavior. All results indicate the presence of asphaltene precipitation problems. The conclusions of all screening techniques indicate the presence of an asphaltene precipitation problem (asphaltene instability), which was validated by a thermodynamic fluid model.