ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
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Lab-scale testing and evaluation of microbes' ability to reduce oil viscosity

Muhammad Murtaza, Irfan Khan, Temoor Muther, Fahad Iqbal Syed, Muhammad Farukh Hunain, Muhammad Shakir, Hassan Aziz, Bariya Khan, Muhammad Anas Siddiqui, Muhammad Fasih, and Ajmal Yousif

Dawood University of Engineering and Technology Karachi, Karachi, Pakistan



Received: 24 May 2022  Accepted: 28 October 2022


Microbial enhanced oil recovery (MEOR) is a tertiary oil recovery method which involves the injection of carefully screened microorganisms into the formation resulting in in situ fermentation to improve oil recovery performance. Improvement in the recovery of oil with the help of microbes could be achieved through several efficient mechanisms mainly through interfacial tension and wettability reduction. This research is performed on a laboratory scale, focused on crude oil samples screening, taken from shallow reservoirs with lower API gravity to study the impact of microbes on the viscosity reduction to cause the degradation of heavy oil into light oil. The crude from the reservoir can be recovered to the surface using driving forces that can be evolved due to the by-product gases of microbes and the resultant elevated reservoir pressure.

In this study, the fusing and mixing of different bacteria strains are successfully conducted on multiple crude oil samples, with API gravity of 39, 34, and 30, while a sample of heavy crude oil with API gravity of 14. Detailed laboratory investigation is performed and results are discussed. The laboratory results demonstrate that viscosity of crude sample is reduced which contributes positively in oil recovery. Compared to other tertiary oil recovery methods, MEOR can be an economical and environmentally friendly alternative depending on the understanding of the reservoir physics and the chemistry of the injected microbe’s response which is found to be different for every individual crude oil sample.

Keywords: MEOR; Crude oil samples; Microbes generation; Gram staining; Incubation of microbes; Viscosity reduction

Full paper is available at

DOI: 10.1007/s11696-022-02581-7


Chemical Papers 77 (4) 1869–1878 (2023)

Monday, May 20, 2024

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