On the Prediction, Prevention and Remediation of Asphaltene Deposition

Abstract

Asphaltene deposition is a flow assurance problem that threatens the continuous production of crude oil. This problem is likely to get worse because of the current tendency to produce from deeper waters and also due to the implementation of enhanced oil recovery operations based on miscible injection of CO2 or hydrocarbon gas. In this article we present a review of the asphaltene precipitation and deposition problem in oil production, and we describe the commercial techniques used for its determination and quantification as well as their limitations. We also discuss the important progress achieved concerning modeling tools with enhanced capabilities that have been developed to forecast the occurrence and the magnitude of this problem. Prompt recognition of potential asphaltene deposition issues, either for new fields or as part of enhanced oil recovery projects, is necessary to implement successful prevention or mitigation strategies. Unfortunately, current commercial inhibitors have mixed results in the field and in some cases are responsible for worsening the deposition problem. After a thorough investigation we have elucidated a multi-step mechanism of asphaltene precipitation, aggregation and aging, which explains the poor performance of some chemicals and the limited capabilities of the current testing protocols. We provide some ideas for a new generation of asphaltene inhibitors and, for the cases in which asphaltene deposition has already occurred, we also provide a list of common techniques and best practices used for its remediation. With this work we aim to provide the reader with a broad understanding of this complex problem and to offer a starting point for the development of cost/effective strategies to manage asphaltene deposition in increasingly complex environments.

Efficient Algorithm for the Prediction of Pressure–Volume–Temperature Properties of Crude Oils Using the Perturbed-Chain Statistical Associating Fluid Theory Equation of State

“…Schematic of the SARA-based characterization method. Adapted with permission from ref . Copyright 2015 Society of Petroleum Engineers (SPE).…”

Investigation of Asphaltene Deposition at High Temperature and under Dynamic Conditions

“…These solid-like aggregates may have less tendency to stick onto the metallic surface. The effect of temperature on the morphology of asphaltene aggregates has been studied under the microscope . According to Khaleel et al, the asphaltene aggregates collected under ambient conditions were partially redissolved into the oil, whereas those collected at 120 °C were more solid-like and hard to redissolve.…”

“…The effect of temperature on the morphology of asphaltene aggregates has been studied under the microscope . According to Khaleel et al, the asphaltene aggregates collected under ambient conditions were partially redissolved into the oil, whereas those collected at 120 °C were more solid-like and hard to redissolve. In the meantime, the reduced effective diameter of the tubing increases the shear force in the packed bed column.…”

Laser-Based Ionization: A Review on the Use of Matrix-Assisted Laser Desorption/Ionization and Laser Desorption/Ionization Mass Spectrometry in Petroleum Research

“…One particular molecular class of interest is the asphaltene fraction, which is the n -heptane-insoluble (toluene-soluble) extraction of a vacuum residue. Asphaltenes have proven difficult to characterize as a result of their diverse chemical nature, being made up of highly condensed aromatics with increased amounts of heteroatoms, and their tendency to aggregate in solution. , These factors can potentially create problems during downstream refining because their presence imparts an increased viscosity on the crude oil and they often foul the heat exchangers during the distillation process. , They are also a concern for flow assurance of upstream operations because they can potentially plug the well head . On a positive note, asphalt (which contains mostly asphaltene molecules) has found unique usage in paving roads, roofing, and other construction applications.…”