Monodisperse Thermodynamic Model Based on Chemical + Flory–Hüggins Polymer Solution Theories for Predicting Asphaltene Precipitation

Abstract

Asphaltene precipitation is traditionally modeled using the Flory−Huggins polymer solution theory. The existing thermodynamic models, generally, do not take into account the aggregation/association phenomena in the system. This work aims at providing a monodisperse thermodynamic model for estimating asphaltene precipitation by taking into account the aforementioned phenomena. The chemical theory of associated solutions with physical interactions along with the Flory− Huggins polymer solution theory is applied to develop this model. The results of this method are compared with some selected experimental data from the literature. It is shown that taking into account the aggregation/association phenomena in the system can lead to better predictions of the model. Moreover, it is shown that this method simplifies to the existing activity coefficient based models when ignoring the association.

Behavior of Asphaltene Adsorption onto the Metal Oxide Nanoparticle Surface and Its Effect on Heavy Oil Recovery

“…To obtain pure asphaltene sample, these steps should be repeated until the solution become almost transparent. The filtered asphaltene and the filter paper are dried in a lidded container for several days [12]. To avoid oxidization of asphaltene, it can be dried under nitrogen steam; even though, this step is not included in the ASTM method.…”

“…Reduction in the amount of recoverable oil and snag in the wellbore and surface facilities are some of these problems which significantly increase the operational costs [12][13][14][15][16]. Accordingly, a solution to remove or reduce the dissolved asphaltene in the oil or prevent its precipitation is crucial [3].…”

Thermodynamic modelling of asphaltene precipitation and related phenomena

“…One example of such modifications is based on including a binary interaction parameter [108] that characterises the interaction between unlike molecules, as applied by Pazuki and Nikookar [109] and Mofidi and Edalat [110]; this interaction parameter is determined as a function of molecular weight [109,110]. Mohammadi et al [111] have combined the approach with chemical theory to account for asphaltene self-association resulting in n-mer aggregates. The theory has been also extended to predict asphaltene concentration gradients in oil reservoirs by incorporation of a gravitational term [112].…”

Fully implicit compositional simulator for modeling of asphaltene deposition during natural depletion

“…The solid models have been widely used in the reservoir simulators due to the flexibility and simple application [13] .…”