An Experimental Investigation of Asphaltene Aggregation under Carbon Dioxide Injection Flow in Ultra-Low-Permeability Pore Structure
Abstract
One of the major problems during gas injection in unconventional reservoirs is asphaltene precipitation and deposition. Asphaltenes can reduce the pore throat in the reservoir and plug the surface and subsurface equipment during the production process, thus, result in oil production reduction with significant financial consequences. The impact of carbon dioxide (CO2) gas injection on asphaltene deposition in unconventional reservoirs still poorly investigated. This research investigates the impact of CO2 gas injection on asphaltene aggregation in ultra-low-permeability pore structures, mainly present in unconventional shale resources. First, the minimum miscibility pressure (MMP) of crude oil with CO2 was determined using the slim tube technique. Then, several CO2 injection pressures were selected to conduct the filtration experiments using a specially designed filtration apparatus. All pressures selected were below the MMP. Various sizes of filter paper membranes were used to study the effect of pore structure on asphaltene deposition. The results showed that asphaltene weight percent was increased by increasing the pressure and a significant asphaltene weight percentage was observed on smaller pore size structures of the filter membranes. The visualization tests revealed the process of asphaltene precipitation and deposition and showed that asphaltene particles and clusters were precipitated after one hour and fully deposited in the bottom of the test tube after 12 hours. High-resolution photos of filter paper membranes were presented using microscopy imaging and scanning electron microscopy (SEM) analysis; these photos highlighted the asphaltene particles inside the filter paper membranes and pore plugging was observed. The study's findings will contribute to a better understanding of the main factors influencing the stability of asphaltene particles in crude oil under immiscible CO2 injection pressure, particularly in nano pores, which are predominant in shale unconventional resources.
Recommended Citation
M. Elturki and A. Imqam, "An Experimental Investigation of Asphaltene Aggregation under Carbon Dioxide Injection Flow in Ultra-Low-Permeability Pore Structure," Proceedings of the SPE Canadian Energy Technology Conference (2022, Calgary, Alberta, Canada), Society of Petroleum Engineers (SPE), Mar 2022.
The definitive version is available at https://doi.org/10.2118/208950-MS
Meeting Name
SPE Canadian Energy Technology Conference (2022: Mar. 16-17, Calgary, Alberta, Canada)
Department(s)
Geosciences and Geological and Petroleum Engineering
International Standard Book Number (ISBN)
978-161399839-7
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2022 Society of Petroleum Engineers (SPE), All rights reserved.
Publication Date
17 Mar 2022
Comments
The authors would like to acknowledge the National Science Foundation, Chemical, Biological, Environmental, and Transport systems for funding the work under grant no. CBET‐1932965.