Microscopy techniques applied to submicron characterization of oilfield produced water
AuthorsMedina, Sandra Constanza
Anjum, Dalaver H.
Behzad, Ali Reza
Vilagines, Regis D.
Tabatabai, S. Assiyeh Alizadeh
KAUST DepartmentBiological and Environmental Science and Engineering (BESE) Division
Bioscience Core Lab
Environmental Science and Engineering Program
Imaging and Characterization Core Lab
Water Desalination and Reuse Research Center (WDRC)
Online Publication Date2021-05-26
Print Publication Date2021-05
Embargo End Date2023-05-26
Permanent link to this recordhttp://hdl.handle.net/10754/669277
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AbstractProduced water (PW) and formation water are complex mixtures of hydrocarbons and water produced at oil and gas upstream facilities. Submicron oil droplets represent a multitude of issues affecting the performance of downstream advanced water treatment processes, such as micro and ultra-filtration processes. Conventional de-oiling technologies do not efficiently remove submicron oil droplets in PW. An accurate characterization of submicron oil droplets and contaminants is required to improve PW treatment technology. In this study, a methodology for visualization and quantification of submicron oil droplets size distribution (DSD), using optical and electron microscopy techniques, was developed. Various microscopy techniques were evaluated, including epifluorescence microscopy (EpiFM), confocal laser scanning microscopy (CLSM), cryogenic scanning and transmission electron microscopy (cryo-SEM and cryo-TEM, respectively). Synthetic PW was used to improve and standardize the sample preparation and characterization methodology. The improved methodology was then tested with two PW samples from different oilfields in the Middle East region. Two methods were developed for the determination of DSD in oilfield PW samples. The first method is suitable for highly polydisperse PW samples with oil droplets larger than 250 nm. This method is based on using low-temperature agarose to immobilize the samples, avoiding coalescence, and allowing clear visualization of the oil droplets at high magnification in EpiFM. The second method is suitable for concentrated PW samples and oil droplets as small as 20 nm in size. This method is based on cryo-TEM with plunge freezing and without the use of agarose for sample immobilization. The agarose-immobilization technique was also applied for sample preparation in cryo-SEM. Cryo-SEM fixation by high-pressure freezing (HPF) preserved the morphology of oil droplets in synthetic oil-concentrated samples and allowed its visualization in a wide range of sizes from 50 nm up to 20 μm.
CitationMedina, S. C., Anjum, D. H., Behzad, A. R., Vilagines, R. D., Tabatabai, A., & Leiknes, T. (2021). Microscopy techniques applied to submicron characterization of oilfield produced water. Journal of Petroleum Science and Engineering, 108930. doi:10.1016/j.petrol.2021.108930
SponsorsThis work was supported by the King Abdullah University of Science and Technology (KAUST), Kingdom of Saudi Arabia. This research did not receive any specific grant from funding agencies in the public or commercial sector