Permittivity Spectrum of Low-Loss Liquid and Powder Geomaterials Using Multipoint Reentrant Cavities

[EN] Permittivity is a useful tool to characterize the composition and quality of many geomaterials. In general, the non-resonant permittivity measurement methods exhibit a higher degree of uncertainty than their resonant counterparts. In resonant measurements, the reduction in uncertainty comes typically with a loss in broadband. This article describes the theory, design, and application of multipoint coaxial reentrant resonant cavities applied to low-loss geomaterials at different temperatures. Specifically, a full-wave method based on circuit analysis is developed and applied for a circular corrugated waveguide. Moreover, the mode-matching method is applied to calculate the generalized admittance matrix (GAM). Two multipoint cavities and software were built and validated. The first cavity has five resonant frequencies, between 170 MHz and 2.3 GHz, and the second has four resonant frequencies, between 1.3 and 8.6 GHz. Thus, this method allows for ¿broadband-resonant¿ measurements. The permittivity values of liquid hydrocarbons, powdered kerogen, and pyrite are shown.Alvarez, JO.; Penaranda-Foix, FL.; Catalá Civera, JM.; Gutiérrez Cano, JD. (2020). Permittivity Spectrum of Low-Loss Liquid and Powder Geomaterials Using Multipoint Reentrant Cavities. IEEE Transactions on Geoscience and Remote Sensing. 58(5):3097-3112. https://doi.org/10.1109/TGRS.2019.2948052S3097311258

Artificial Maturation Studies of Polymethylenic Plant Biopolymers: Investigating the Chemical Alterations from Plant Material to Coal

The thermal maturation and alternation of vascular plant material into coals and as expelled petroleum-like compounds is the main focus of this dissertation. Utilizing artificial maturation studies, like hydrothermal liquefaction, yields useful information regarding how plant material is preserved in coals and the potential certain plant biopolymers possess to generate liquid fuels is acquired. The studies within this dissertation focus on utilizing the aliphatic biopolymers, cutin, cutan, and suberan, found in the epidermis of certain plants. These biopolymers contain minimal amounts of heteroatoms and are comprised of long polymethylenic chains, which are desirable characteristics in generating bio-oils. Additionally, understanding the chemical alterations that occur to these biopolymers during maturation is essential in evaluating their geochemical preservation in coals. To evaluate the potential suberan has to become incorporated into coals and generate expelled oils, hydrothermal liquefaction experiments were conducted on modern, Betula alleghaniensis bark, and ancient, a lignite rich in crypto-eugelinite, samples. Both the bark and the coal display characteristic crystalline and amorphous peaks in solid-state 13C NMR, which is indicative of the presence of suberan. The expelled oil products of both feedstocks were mainly comprised of saturated hydrocarbons. These results suggest that suberan can readily explain the existence of waxy crude oils typically associated with coals and Type III source rocks. The oil generating potential of cutan and cutin were evaluated using skins collected from Agave americana and Capsicum annumm. Both cuticular materials resulted in approximately 35% wt.% bio-oil yields and exhibited heating values of 40.5 MJ kg-1, comparable to those of typical crude petroleum. Furthermore, a two-step hydrothermal liquefaction experiment was successfully employed to reduce the heteroatom content of the produced Agave americana bio-oil. Another focus of this dissertation is understanding the fate of plant materials during peatification and coalification. Humic acids were isolated from several peat swamps across the U.S. as well as a low rank collected from the Yallourn Open Cut in Australia, and analyzed using high resolution mass spectrometry and solid-state 13C NMR. From these analyses photochemically produced particulate organic matter was observed in all the samples. The presence of this material in peats and coals can likely explain the origin of ubiquitously occurring fusinite, macrinite, micrinite, and related inertinite macerals in coal

A mechanistic analysis of naphthenate and carboxylate soap-forming systems in oilfield exploration and production

This project entailed mechanistic aspects of the formation of oilfield soaps. An integrated approach to the study of field deposits was developed leading to an optimised analytical protocol which is one of the major contributions of this thesis. The philosophy behind the choice of techniques was to integrate measurements suitable for bulk and surface properties. The selected and optimised techniques were electrospray mass spectrometry (ES), energy dispersive X-ray (EDAX) and solid state 13C nuclear magnetic resonance (NMR) as well as thermal analysis (TGA/DSC) and interfacial tension (IFT). These allowed for the differentiation of the two end-member types of soaps, namely, calcium naphthenate soap scales and sodium carboxylate soap emulsions, as well as for the identification of chemically-treated deposits and asphaltenes. It was concluded that the analysis of naphthenic acids from field soap deposits in mass spectrometry was a function of: ionisation source, solvent and instrument settings (e.g. voltages). These parameters had a direct effect on the relative detection of particular naphthenic acid species such as the Arn. Though the electrospray (ES) source was observed to lead to a more realistic fingerprint for naphthenic acid extracts, it was also suggested that the atmospheric pressure chemical ionisation (APCI) source could be used in conditions where identification of Arn was the ultimate objective. A series of static bottle tests were devised to simulate the pH changes associated with the occurrence of deposits in the field. The procedures focused on a number of model naphthenic acid systems, as well as acids extracted from field deposits and soap-forming crude oils. Soap formation was found to be a function of the precise aqueous phase (e.g. cations and pH) in addition to the oil phase (e.g. acyclic vs. cyclic/aromatic naphthenic acid content). It was possible to form soap deposits in the laboratory from both indigenous acids, as well as crude oils. Detailed speciation of certain indigenous acids allowed for the identification of Arn and the special properties of this species namely: four carboxylic acid groups by tandem mass spectrometry (MS/MS) and surface properties given by interfacial tension (IFT). Previous literature claims stated that Arn acid presence were solely responsible for the precipitation of calcium naphthenate soap scales. The results in this thesis show that although Arn acids have predominant surface properties, they compete with lower molecular weight acids for aqueous phase cations at high pH values. This was observed in static bottle tests as well as results from field precipitation samples. Fourier-Transform infrared (FTIR) spectroscopy showed potential as a technique for the prediction of soap deposition onset in the laboratory. Supporting experiments were designed to validate a simple thermodynamic model to predict the phase iii behaviour of oil-water-naphthenic acid systems. A sensitivity study showed that the dissociation constants (pKa) of the naphthenic acids were the most important model parameters and could affect predicted output pH values. For indigenous naphthenic acids, alternative procedures for both dissociation constant and partition coefficient were introduced. A comprehensive suite of crude oil analysis and water properties were employed for correlating field soap-forming systems. It was possible to obtain some trends which relate geochemical parameters with bulk crude oil properties, as well as naphthenic acid speciation. Based on this information, a preliminary attempt to establish prediction guidelines for soaps, one of the major contributions in this thesis to the current knowledge of soap-forming systems, is presented.EPRS

Investigating the factors impacting the success of immiscible carbon dioxide injection in unconventional shale reservoirs: An experimental study

Unconventional shale reservoirs are currently gaining significant interest due to the huge hydrocarbon volumes that they bear. Enhanced oil recovery (EOR) techniques have been suggested to increase recovery from shale reservoirs. One of the most promising EOR methods is gas EOR (GEOR), most notably carbon dioxide (CO2). Not only can CO2 increase oil recovery by interacting with the oil and the shale, but it has also been shown to adsorb to the shale rock and thus is effective in both EOR applications and also carbon storage purposes. This research aims to experimentally investigate several of the interactions that may impact CO2 injection in shale reservoirs in hopes of defining and quantifying the factors impacting these interactions and how these factors can contribute to an improvement in oil recovery from these reservoirs. This research begins by undergoing a review and data analysis on immiscible CO2 injection to investigate its injection methods, mechanisms, governing equations, and factors influencing its applicability. Following this, a mathematical simulation was undergone to investigate the different CO2 flow regimes that could occur during CO2 injection in shale reservoirs. The interaction of the CO2 with the shale rock via adsorption was investigated by undergoing several adsorption experiments. The CO2 interaction with the oil was also investigated by undergoing oil swelling which is considered the main mechanism by which oil recovery can be increased during immiscible CO2 injection, and asphaltene experiments to investigate the factors impacting these two interactions. Finally, cyclic CO2 injection was performed to determine the oil recovery potential of GEOR from shale reservoirs --Abstract, page iv

Processing of Heavy Crude Oils

Unconventional heavy crude oils are replacing the conventional light crude oils slowly but steadily as a major energy source. Heavy crude oils are cheaper and present an opportunity to the refiners to process them with higher profit margins. However, the unfavourable characteristics of heavy crude oils such as high viscosity, low API gravity, low H/C ratio, chemical complexity with high asphaltenes content, high acidity, high sulfur and increased level of metal and heteroatom impurities impede extraction, pumping, transportation and processing. Very poor mobility of the heavy oils, due to very high viscosities, significantly affects production and transportation. Techniques for viscosity reduction, drag reduction and in-situ upgrading of the crude oil to improve the flow characteristics in pipelines are presented in this book. The heavier and complex molecules of asphaltenes with low H/C ratios present many technological challenges during the refining of the crude oil

Processing of Heavy Crude Oils

Unconventional heavy crude oils are replacing the conventional light crude oils slowly but steadily as a major energy source. Heavy crude oils are cheaper and present an opportunity to the refiners to process them with higher profit margins. However, the unfavourable characteristics of heavy crude oils such as high viscosity, low API gravity, low H/C ratio, chemical complexity with high asphaltenes content, high acidity, high sulfur and increased level of metal and heteroatom impurities impede extraction, pumping, transportation and processing. Very poor mobility of the heavy oils, due to very high viscosities, significantly affects production and transportation. Techniques for viscosity reduction, drag reduction and in-situ upgrading of the crude oil to improve the flow characteristics in pipelines are presented in this book. The heavier and complex molecules of asphaltenes with low H/C ratios present many technological challenges during the refining of the crude oil, such as heavy coking on catalysts. Hydrogen addition and carbon removal are the two approaches used to improve the recovery of value-added products such as gasoline and diesel. In addition, the heavy crude oil needs pre-treatment to remove the high levels of impurities before the crude oil can be refined. This book introduces the major challenges and some of the methods to overcome them