Journal of Petroleum Science and Engineering 192 (2020) 107213
Available online 1 April 2020
0920-4105/© 2020 Elsevier B.V. All rights reserved.
Integrated reservoir/wellbore production model for oil feld asphaltene
deposition management
Mohammad Ghasemi
a
, Eissa Al-Safran
b, *
a
i-Petroleum Engineering Solution Hub, Norway
b
Petroleum Engineering Department, Kuwait University, Kuwait
A R T I C L E INFO
Keywords:
Integrated modeling
Asphaltene precipitation and deposition
Micellization model
Equation-of-state
Transport mechanism
ABSTRACT
Asphaltene deposition prevention, mitigation, and management remains a major challenge to the oil industry due
to its complexity, poor understanding, and inadequate predictive tools. A literature review study on asphaltene
deposition revealed a lack of integrative models that link reservoir, wellbore, and surface facility to predict
asphaltene deposition taking into account the effect of their interaction on asphaltene deposition. In addition,
most of the existing studies are focused on either modeling the thermodynamics aspects of asphaltene precipi-
tation, or single-phase asphaltene deposition. Therefore, it is critical to model asphaltene deposition under
multiphase fow conditions to, accurately, develop prevention, mitigation, and management strategies, which
depends on not only asphaltene thermodynamics, but also multiphase fow hydrodynamics and behavior. The
objective of this study is to develop a robust systematic approach for predicting asphaltene deposition in pro-
duction system through coupling reservoir and wellbore production models, which provides a cost-effective
optimal mitigation and management strategies. The proposed work in this study integrates fve models,
namely reservoir asphaltene deposition model, equation-of-state (EOS) model, asphaltene thermodynamics
precipitation model, mechanistic multiphase fow model, and asphaltene deposition transport model. The above-
mentioned models are integrated using developed workfow platform, which enables compositional tracking
throughout the entire production system. Furthermore, experimental fuid characterization data was used to tune
the EOS model to ensure accurate phase behavior and volumetric calculations, and to tune the thermodynamic
asphaltene precipitation model. A feld case input data is used to evaluate the proposed integrated model, which
indicates severe asphaltene depositions in production tubing. The proposed model predicted the location and
growth of asphaltene deposition thickness with time and space in the inner production-tubing wall. The model
results also show that local asphaltene deposition reduced tubing cross-sectional area, increasing in-situ super-
fcial oil and gas velocities, thus increasing pressure drop and decreasing fowrate. Sensitivity analyses to
investigate several parameters such as depletion drive mechanism, asphaltene particle size, and injection of CO
2
rich gas on asphaltene deposition show excellent results that are aligned with the physical and theoretical un-
derstanding of asphaltene deposition. These results are critical in selecting, optimizing, and implementing
asphaltene deposition mitigation and management strategies, which affects project economics and safety.
1. Introduction and literature review
Asphaltene precipitation and deposition is a major fow assurance
challenge, which manifests itself in reservoir, production tubing, fow-
line, and process facilities, resulting in poor reservoir management and
production operations. In addition, it poses several operational, safety,
and economic challenges for oil and gas feld project. Although
asphaltene precipitation and deposition depend mainly on fuid
composition and pressure, recent studies show that it also depends in a
lesser amount on temperature and water cut (Kar et al., 2020). In the
following literature review, several asphaltene deposition feld cases are
presented frst. Second, a brief description of the existing asphaltene
precipitation models is presented. Asphaltene deposition models, and
integrated models are discussed in the last section of this literature
review.
Signifcant asphaltene deposition challenges in Hessi Messaoud feld
in Algeria resulted in frequent tubing blockage and cleanout using
asphaltene inhibitors (Haskett et al., 1965). Lichaa (1977) reported that
* Corresponding author.
E-mail address: e.alsafran@ku.edu.kw (E. Al-Safran).
Contents lists available at ScienceDirect
Journal of Petroleum Science and Engineering
journal homepage: http://www.elsevier.com/locate/petrol
https://doi.org/10.1016/j.petrol.2020.107213
Received 16 January 2020; Received in revised form 16 March 2020; Accepted 18 March 2020