Date of Award

December 2022

Document Type


Degree Name

Doctor of Philosophy (PhD)


Petroleum Engineering

First Advisor

Hui Pu


The compositional evaluation and geochemical characterization of twenty wellhead samples from six fields of the heavy oil belt on the western flank of the Middle Magdalena Valley basin in Colombia (MMVB) were completed by analyzing its polar fraction, that is, compounds of Nitrogen, Sulfur and Oxygen (NSO) using 15 Tesla and 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS), combined with negative electrospray ionization (-)ESI and positive atmospheric pressure photoionization (+) APPI. To highlight the sulfur compounds and organic acids, the Propyl Sulfonic Acid (PRS) and Amino-Propyl Silica (APS) fractionations were used respectively.

The results validate the use of high-resolution mass spectrometry, and particularly the petroleomics, to obtain compositional tracers and chemical criteria to identify and classifying highly altered oils of different production fields of the study area according the NSO compounds and its relative abundances, as well the Double Bond Equivalent (DBE) ratios and DBE/Carbon Number plots.

In addition, petroleomics helped the understanding of the genetic and post-genetic properties of severely degraded crude oils, by providing information on 1) the depositional environment of source rock using particular ratios of the oxygenated and sulfur classes by (+)APPI; 2) the thermal maturity by means of specific compounds of nitrogenated classes in (-)ESI; and 3) the intensity of biodegradation using the evaluation of some DBE ratios of oxygenated classes by (-)ESI, which allowed to identify sublevels of differential alterations within crude oils with severe biodegradation, with a new couple of alternative monoaromatic indexes. Finally, the combination with additional analytical techniques such as gas chromatography coupled to mass spectrometry (GC-MS) and elemental analysis - isotope ratio mass spectrometry (ES-IRMS) made it possible to verify the need to use ultra-high resolution techniques (such as petroleomics) in severely degraded crude oils, identify at least two hydrocarbon charge episodes in the area and propose biological mechanisms that explained the differential biodegradation in the crude oils of the basin's heavy hydrocarbon belt.

Available for download on Saturday, January 18, 2025