Highly fractured carbonate reservoirs are a class of reservoirs characterized by high conductivity fractures surrounding low permeability matrix blocks. In these reservoirs, wettability alteration is a key method for recovering oil. Water imbibes into the matrix blocks upon water flooding if the reservoir rock is water-wet. However, many carbonate reservoirs are oil-wet. Surfactant solution was used to enhance spontaneous imbibition between the fractures and the matrix by both wettability alteration and ultra-low interfacial tensions. The first part of this study was devoted to determining the wettability of reservoir rocks using Amott-Harvey Index method, and also evaluating the performance of surfactants on wettability alteration, based on the contact angle measurement and spontaneous imbibition rate and ultimate oil recovery on oil-wet reservoir cores. The reservoir rocks have been found to be slightly oil-wet. One cationic surfactant BTC8358, one anionic surfactant and one ultra-low IFT surfactant formulation AKL-207 are all found to alter the wettability towards more water-wet and promote oil recovery through spontaneous imbibition. The second part of the study focused on the parameters that affect wettability alteration by surfactants. Some factors such as core dimension, permeability and heterogeneity of porous medium are evaluated in the spontaneous imbibition tests. Higher permeability leads to higher imbibition rate and higher ultimate oil recovery. Heterogeneity of core samples slows down the imbibition process if other properties are similar. Core dimension is critical in upscaling from laboratory conditions to field matrix blocks. The imbibition rate is slower in larger dimension of core. Further, we investigated the effects of EDTA in surfactant-mediated spontaneous imbibition. Since high concentration of cationic divalent ions in the aqueous solution markedly suppresses the surfactant-mediated wettability alteration, EDTA improved the performance of surfactant in the spontaneous imbibition tests. It is proposed in the thesis that surfactant/EDTA-enhanced imbibition may involve the dissolution mechanism. More experiments should be conducted to verify this mechanism. The benefits of using EDTA in the surfactant solution include but not limited to: altering the surface charge of carbonate to negative, producing the in-situ soap, reducing the brine hardness, decreasing the surfactant adsorption, and creating the water-wet area by dissolving the dolomite mineral. / text

Gas wells suffer a decrease in productivity because of the formation of a liquid hydrocarbon “condensate” in the near wellbore area. This "condensate" forms near producing wells when the flowing pressure is below the reservoir fluid's dew point. Several methods have been shown to temporarily alleviate this problem, but eventually the condensate bank reforms and the productivity again decreases. The use of surfactants to alter the near wellbore wettability to neutral wetting is a potential longer term solution to liquid blocking in these reservoirs. This alteration increases the gas and liquid relative permeabilities and thereby the productivity by reducing the residual liquid saturation. This enhancement allows the accumulated liquid to flow and is durable as long as the wettability alteration is persistent. This solution has been shown to be successful through core flood experiments and field trials in high permeability sandstones, but no improvements had been observed in low permeability cores. As the global demand for energy increases, the petroleum industry has begun to develop unconventional (low permeability) assets, new techniques are needed to maintain and improve their productivity. Liquid blocking in these wells can have a much larger impact on both the gas and condensate production in such low permeability formations. Applying this technique increases both gas and condensate mobility and should increase the economic producing life of these wells. Core flood experiments were conducted to investigate the ability of a chemical treatment to alter the wettability of low permeability sandstones. Previous experimentation did not find any improvement because the increased capillary forces prevented the treatment solution from being easily displaced. This concealed the benefit achieved when the wettability was altered. These experiments recorded smaller relative permeability increases compared to higher permeability core floods, so super critical carbon dioxide was tested as an alternative solvent. While the new treatment was more injectable, it was not as successful at altering wettability. Progress has been made on a solution to liquid blocking in low permeability sandstones, but additional research needs to be completed to further optimize this method. / text

The sorption of nonionic surfactant oxyethylated alcohols Lutensol AO – 10 and Cu (II) ions on activated carbon AquaSorb HS has been investigated. The kinetic investigations have revealed that the sorption of nonionic surfactant was the sufficiently slow process and required 7 days to reach equilibrium. The equilibrium sorption of the Cu (II) ions was attained within 24 h. ...

In the present study the effect of one commercially available anionic surfactant on the formation/dissociation of hydrate from a gas mixture of 90.5 % methane – 9.5% propane mixture was investigated. Surfactants are known to increase gas hydrate formation rate. Memory water was used and the experiments were carried out at three different degrees of undercooling and two different surfactant concentrations. In addition, the effect of the surfactant on storage capacity of gas into hydrate was assessed. The morphology of the growing crystals and the gas consumption were observed during the experiments. The results show that branches of porous fibre-like crystals are formed instead of dendritic crystals in the absence of any additive. Finally, the addition of 2200 ppm of SDS was found to increase the mole consumption for hydrate formation by 4.4 times.

Considerable research has been done to improve hydrate formation rate. One of the ideas is to introduce mechanical mixing which later tend to complicate the design and operation of the hydrate formation processes. Another approach is to add surfactant (promoter) that will improve the hydrate formation rate and also its storage capacity to be closer to the maximum hydrate storage capacity. Surfactant is widely known as a substance that can lower the surface or interfacial tension of the water when it is dissolved in it. Surfactants are known to increase gas hydrate formation rate, increase storage capacity of hydrates and also decrease induction time. However, the role that surfactant plays in hydrate crystal formation is not well understood. Therefore, understanding of the mechanism through morphology studies is one of the important aspects to be studied so that optimal industrial processes can be designed. In the present study the effect of three commercially available anionic surfactants which differ in its alkyl chain length on the formation/dissociation of hydrate from a gas mixture of 90.5 % methane – 9.5% propane mixture was investigated. The surfactants used were sodium dodecyl sulfate (SDS), sodium tetradecyl sulfate (STS), and sodium hexadecyl sulfate (SHS). Memory water was used and the experiments for SDS were carried out at three different degrees of under-cooling and three different surfactant concentrations. In addition, the effect of the surfactant on storage capacity of gas into hydrate was assessed. The morphology of the growing crystals and the gas consumption were observed during the experiments. The results show that branches of porous fibre-like crystals are formed instead of dendritic crystals in the absence of any additive. In addition, extensive hydrate crystal growth on the crystallizer walls is observed. Also a “mushy” hydrate instead of a thin crystal film appears at the gas/water interface. Finally, the addition of SDS with concentration range between 242ppm – 2200ppm (ΔT =13.10C) was found to increase the mole consumption for hydrate formation by 14.3 – 18.7 times. This increase is related to the change in hydrate morphology whereby a more porous hydrate forms with enhanced water/gas contacts.

The practical applications of surfactant solutions in confined geometries require a thorough understanding of the system properties. Coarse-grained simulation techniques are useful for studying the qualitative behaviour of these systems, whereas the atomistic molecular dynamics (MD) technique can be used to obtain a molecular-level description. In this work, canonical MD simulations were performed using GROMACS version 4.0 to investigate the self-assembling behaviour of sodium octanoate (SO) confined between two parallel walls. In particular, the effects of gap size, wall type, and surfactant concentrations on the morphology of the surfactant aggregates were studied to gain in-depth knowledge of the system. The simulation results reveal that the morphology of the micelles formed between two parallel walls are affected not only by the gap size and surfactant concentration, but also by the nature and characteristics of the confining walls. With the graphite walls, most octanoate molecules are adsorbed at lower concentrations, but they form micellar aggregates as the surfactant concentration increases. Spherical micelles were found in the larger gaps (4 nm and 5 nm) but not in the smaller gap (3 nm), and the micellar shape also changes with increasing surfactant concentration. SO forms bilayer structures instead of spherical micelles between two silica walls. Interestingly, in the hydrophilic silica confinement, the orientation of these bilayers changes with gap sizes, whereas in the hydrophobic silica confinement, these bilayers remain perpendicular to the wall in all cases. Potentials of mean force between different molecules and atomic groups were determined under different conditions in order to develop a better understanding of the simulation results. It reveals, the presence of the confinement can alter the intermolecular interactions among the surfactant molecules, which, in turn, directly affects the self-assembling process, particularly the size and shape of the aggregates. Indeed, the formation of bilayers in silica wall confinement, as opposed to spherical micelles in graphite confinement, is caused by the enhanced electrostatic interactions between the charged atoms in the solution. The results of this study are expected to provide further insight into the self-assembling behaviour of confined surfactant systems, and may ultimately lead to the development of novel nanomaterials.

For over a decade, diquaternary ammonium gemini surfactants have shown promise as non-viral gene delivery agents in both in vitro and in vivo systems. Their continued development, however, requires an understanding of their biological fate. The absence of identification and quantification methods that can achieve that goal is what drove the development of simple and rapid mass spectrometry (MS)-based methods; the focus of my Ph.D. dissertation. Prior to the development of these MS-based methods, an understanding of the gas phase behavior of diquaternary ammonium gemini surfactants is required. The development of a universal fragmentation pathway for gemini surfactants was achieved using low resolution and high resolution MS instruments. Single stage (MS), tandem stage (MS/MS and quasi-multi-stage (quasi MS3) mass spectrometry analysis allowed for the confirmation of the molecular composition and structure of each gemini surfactant through the identification of common and unique mass to charge values. Understanding the fragmentation behavior allowed for the specific identification and/or quantification of gemini surfactants by MS-based methods; including liquid chromatography low resolution tandem mass spectrometry (LC-LR-MS/MS), fast chromatography low resolution tandem mass spectrometry, fast chromatography high resolution mass spectrometry, desorption electrospray ionization low resolution mass spectrometry and matrix assisted laser desorption ionization high resolution mass spectrometry. We hypothesized that a LC-LR-MS/MS method would be the most effective quantitative method for the quantification of N,N-bis(dimethylhexadecyl)-1,3-propane-diammonium dibromide (G16-3) within PAM212 cellular lysate; achieving the lowest lower limit of quantification (LLOQ). Although the LC-LR-MS/MS method achieved a LLOQ suitable for analysis of G16-3 within PAM212 cell lysate, its limitations made it an inefficient method. In comparison, the four alternative mass spectrometry methods were faster, more efficient and less expensive than a conventional LC-LR-MS/MS method for the post transfection quantification of G16-3 within PAM212 cell lysate to be determined; 1.45 ± 0.06 μM. Future application of the universal fragmentation pathway and each MS-based quantification method will be beneficial for the future development of diquaternary ammonium gemini surfactants to further understand their post transfection fate.

Surfactant-templated, sol-gel based methodologies for the synthesis of tailored, nanostructured, hybrid inorganic–organic materials are incredibly powerful and versatile. Although growth in this field has been explosive in recent decades, a lot of room remains to contribute to the design and synthesis of new materials, as well as the development of advanced applications. In the work described herein, we firstly explored the synthesis of thick, mesoporous organosilica films and their application as functional coatings for solution-based, fibre-optic heavy metal sensors. Notably, sub-ppm level detection was observed for the detection of Pb(II) in mixed aqueous–organic media in short timeframes, and progress has been made toward synthesizing organotitania films that would allow for heavy metal sensing in purely aqueous solution. Furthermore, the utility of these types of surfactant-templated, organically-functionalized, mesostructured coatings has been preliminarily extended to other types of optical devices for heavy metal sensing. We have also explored the use of designer amphiphilic, alkyl oligosiloxane precursors for the tightly-controlled formation of thin, self-templated, hybrid nanostructured films. Moreover, films bearing uniaxial 2D hexagonal alignment over macroscopic length scales were obtained using polymer-treated substrates to control the interfacial interactions between the film precursors and the substrate surface. In addition, a relatively mild UV / ozone treatment was employed to remove the alkyl moieties from the films to yield porous materials without catastrophic loss of the as-synthesized, mesostructural order. Lastly, novel chiral, binaphthylene-based, periodic mesoporous organosilica (PMO) materials have been prepared. With the aim of demonstrating chiral recognition with such materials, porous, co-continuous capillary monoliths have been synthesized and applied as chiral stationary phases in nano-HPLC and CEC. Notably, enantioselective interactions between our materials and a chiral acetal-based analyte have been observed. Quantification of these enantioselective interactions in chiral PMOs by isothermal titration microcalorimetry is also being pursued. It has thus been demonstrated that a wide array of different functional materials may be accessed through template-based synthetic strategies. By varying parameters such the starting monomers, the sol composition, and the interfacial interactions between reacting species and a given substrate (to name a few), the resulting materials may be tailored to meet the demands of new and emerging technologies. / Thesis (Ph.D, Chemistry) -- Queen's University, 2011-05-24 19:50:17.478

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Baigiamajame magistro darbe apžvelgiama dyzelinių degalų gamyba, sudėtis ir jų priedai. Aprašyti dyzelinių variklių išskiriami teršalai bei jų mažinimo principai. Nagrinėjamos degalų mišinių struktūrinės ypatybės bei savybės. Išnagrinėti mišinių gavimo būdai ir įrenginiai. Atlikti eksperimentiniai tyrimai, kurių metu skirtingais kiekiais ir esant skirtingiems parametrams buvo maišomas dyzelinas su vandeniu ir įvairiais stabilizuojančiais priedais. Gautos degalų mišinio vandens dalelių dydžio priklausomybės. Nagrinėta stabilizuojančių priedų įtaka vandens dalelių dydžiui bei mišinio išsisluoksniavimo laikui. Apskaičiuotas mokėtinas taršos mokestis naudojant gryną dyzeliną ir degalų mišinį. Pateiktos darbo išvados. Darbą sudaro 8 dalys: įvadas, dyzelinių degalų apžvalga, dyzelinių variklių deginių sudėties analizė, degalų mišinių įtaka variklio darbingumui, mišinių gavimo būdai ir įrenginiai, atlikti eksperimentiniai tyrimai, ekonominis įvertinimas, išvados. Darbo apimtis − 65 p. teksto be priedų, 39 paveikslai, 13 lentelių. Atskirai pridedami darbo priedai. / This Master Thesis rewievs diesel fuel production, composition and accessories. Discribed the emissions, resulting from diesel engines and their reduction. Examined structural features and properties of the fuel blends and fuel emulsions. Overview of formulas obtained getting stable emulsions. Receiving experimental studies in which different quantities of diesel and water were mixed with certain parameters. The resulting particle size dependence of water in the emulsion. Visited additives on particle size and mixture of delamination time. Polution tax calculated using pure diesel fuel and fuel blend. Work consists of 8 parts: introduction, overview of diesel fuel in diesel engines, exhaust composition analysis of the fuel blends on the engine capacity to work, blends of receipt of techniques and equipment to carry out experimental studies, economic evaluation, and conclusions. Work volume: 65 pages without additions, 39 illustrations, 13 tables. Additions to work.