Review of Asphaltene Deposition Modeling in Oil and Gas Production

Abstract

Asphaltene precipitation and deposition in the reservoir, near-wellbore region, and pipelines is one of the critical problems in flow assurance. It can cause a blockage of pore throats and reduce the permeability of the rock and the production rate in pipelines. Therefore, a thorough investigation of the structure and characterization of asphaltenes is essential to control this issue. Developing a reliable model to predict the deposition of asphaltenes in the reservoir and pipes is key to further understand this phenomenon. In this paper, the asphaltene structure is discussed in terms of the techniques used to identify the structure, molecular weight, size, and geometry of asphaltene. The thermodynamic characterization of asphaltenes is highly dependable upon the structure and molecular weight of particles; thus, a brief overview of the precipitation of asphaltenes is given. A detailed comparison of the available models in the literature is provided for asphaltene deposition in reservoirs as well as flowlines. Several mechanisms are assumed to develop current models; however, more research on closure relationships and tuning parameters is needed because most of them are not universal and are dependent upon the conditions of the flow. The lack of complete data poses another challenge that hinders the ability to evaluate the accuracy of existing models. Industrial case studies and treatment methods are discussed to understand the application of the theories to practical issues and bridge the gap between theory and field conditions. Discoveries from the field and lab-scale experiments are provided in the paper to assist in addressing the mechanisms of the proposed models and the link between theory and application. Overall, this paper provides a comprehensive review of asphaltene deposition modeling and discusses potential improvements for current models.

Review of Asphaltenes in an Electric Field

“…However, electrochemical processes going on at the electrodes surfaces in the presence of water seem to be neglected. If the potential applied to two electrodes present in aqueous solution is higher than the water electrolysis potential (1.23 V), water is split according to the following reactions at the anode, eq (1), and the cathode, eq (2) given in Figure 8. At potentials below the water electrolysis potential, reduction of oxygen present in water may take place at the cathode as described in eqs ( 3) and (4).…”

“…Asphaltene deposition in producing wells, pipelines, and surface facilities leads to detrimental production and operational problems with great economic impact. Asphaltene precipitation and deposition in downstream and upstream processing facilities may lead to plugging of pipeline and wellbores, deposition of solids in storage tanks, corrosion and fouling of safety valves, 1 and formation of coke in refineries. 2,3 Asphaltene deposition costs the oil industry billions of dollars every year, including reduction of production capacity, wells shut-in, and implications of the management techniques.…”

“…Asphaltene deposition in producing wells, pipelines, and surface facilities leads to detrimental production and operational problems with great economic impact. Asphaltene precipitation and deposition in downstream and upstream processing facilities may lead to plugging of pipeline and wellbores, deposition of solids in storage tanks, corrosion and fouling of safety valves, and formation of coke in refineries. , Asphaltene deposition costs the oil industry billions of dollars every year, including reduction of production capacity, wells shut-in, and implications of the management techniques. , For instance, it was reported from an oil field in the Gulf of Mexico that the cost of a well shut-in for a cleanup operation due to asphaltene deposition was approximately $70 million/well . Moreover, the asphaltene management cost, which includes inhibition, treatment, and cleanup aggravates the financial burden of asphaltene deposition.…”

Insights into the Self-Aggregation of Porphyrins and Their Influence on Asphaltene Aggregation

“…Asphaltenes, regarded as the most complex and polar components in crude and heavy oil, were responsible for a series of problems during transportation and refining of crude and heavy oil. − The deposition properties of asphaltene are prone to lead to the blockage of the pore throats of oil layers and gathering in pipeline transportation of crude oil, thereby reducing the oil recovery rate and affecting the normal production. − In addition, the aggregation of asphaltene can lead to the formation of coke for blocking the pipelines and reactors during the processing of heavy oil. All the problems caused by asphaltenes are attributed to their special structure and tendency to form nanoaggregates, flocculates, and precipitates.…”

Particulate Deposition Modeling for Predicting Paraffin Thickness in Flowlines: Application of Data Analytics for Model Parameters

“…Wax deposition is one of the significant flow assurance issues along with hydrates and asphaltenes . Waxy crude oil consists of high-molecular-weight linear n -alkanes that are usually dissolved in oil at reservoir conditions. − However, when the temperature falls below the wax appearance temperature (WAT) in the production, waxy components begin precipitating out of the oil, as shown in Figure .…”