Asphaltene Precipitation: A Review on Remediation Techniques and Prevention Strategies

Abstract

In the last few years, large efforts have been made to develop advanced and smart technologies that can predict and prevent asphaltene precipitation. In the history of asphaltene deposition science, two schools of thought have emerged to predict the phase behavior of asphaltene. One school uses colloidal science techniques, believing that asphaltene exists in oil at a colloidal state. The other school adopts thermodynamic methods, believing that the asphaltene occurs in oil in a true liquid state. The main drawdowns of asphaltene deposition in some reservoirs that are prone to asphaltene precipitation are the alteration of reservoir rock's wettability, and the plugging of the formation, flowlines and separation facilities. Different production strategies have been developed to eliminate or reduce the asphaltene precipitation. As asphaltene properties are dependent on its composition, as well as the reservoir temperature and pressure, thermodynamic and kinetic control strategies are utilized to control the pressure and temperature of the system or the conditions of solid formation. Common intervention techniques include stimulating the well periodically using a mixture of acid, xylene, and mutual solvent. Advancement in the asphaltene flocculation-inhibitor treatments allows it to be used in treating the asphaltene in the reservoir without damaging the formation. There are some limitations and environmental restrictions on the current conventional intervention techniques associated with using low flash-point chemicals. These limitations can be resolved by using environmentally friendly techniques, such as laser energy to disturb asphaltene particles. This paper will discuss the asphaltene precipitation and deposition phenomena, preventive and detection techniques, and intervention methods and their limitations, providing a comprehensive overview on the current practice in asphaltene remediation and prevention.

New Molecular Insights into Aggregation of Pure and Mixed Asphaltenes in the Presence of n-Octylphenol Inhibitor

“…23 For instance, they are used with solvents as dispersive media that facilitate the mass transfer to the oil phase due to a reduction in the viscosity. 2,3 Another reason is that using a concentrated surfactant is prone to forming micelles that can be easily lost in the reservoir (through adsorption) without reaching the oil phase. Use of a solvent helps to inject it at concentrations below the critical micelle concentration (CMC).…”

“…The asphaltene deposition occurs upon a change in thermodynamic conditions during hydrocarbon production and transportation . Based on the solubility theory, the asphaltene is soluble in oil at reservoir conditions . A decrease in pressure and temperature during the oil production or a change in the composition during improved oil recovery/enhanced oil recovery (IOR/EOR) can destabilize the asphaltene, causing asphaltene precipitation and deposition. , When the thermodynamic condition approaches the onset of asphaltene stability, the asphaltene molecules begin to agglomerate as nanoaggregates.…”

“…Octylphenol (OP), nonylphenol, and ethoxylated nonylphenol are usually considered as effective asphaltene inhibitors based on inhibitor screening. ,,,− Although phenols are recognized as proper surfactants in terms of inhibition efficiency and economic prospect, they are not generally used as pure due to various technical and nontechnical aspects, and usually they will be mixed with asphaltene solvents and diesel to be used in industrial/field scale . For instance, they are used with solvents as dispersive media that facilitate the mass transfer to the oil phase due to a reduction in the viscosity. , Another reason is that using a concentrated surfactant is prone to forming micelles that can be easily lost in the reservoir (through adsorption) without reaching the oil phase. Use of a solvent helps to inject it at concentrations below the critical micelle concentration (CMC).…”

Performance of asphaltene stability predicting models in field environment and development of new stability predicting model (ANJIS)

“…This interruption of hydrocarbon production could be occurred due to the formation of hydrates, emulsions, inorganic scales and organic deposits (Mansoori 2010). Among these above-mentioned solids, asphaltene is regarded to be the most troublesome organic solid deposit because it possesses complex formation phenomenon and therefore requires complicated, diverse and expensive treatment solutions (Melendez-Alvarez et al 2016;Al-Qasim et al 2018;Thou et al 2002).…”

Successful approach to mitigate the asphaltenes precipitation problems in ESP oil wells

“…It reduces the lifetime of the ESP. The centrifugal forces of the ESP increase the quantities of the asphaltenes precipitation (Limanowka et al 1999;Al-Qasim et al 2018).…”