http://theses.ncl.ac.uk/jspui/handle/10443/2258 2026-02-06T05:53:26Z 2026-02-06T05:53:26Z test2, test2 http://theses.ncl.ac.uk/jspui/handle/10443/4467 2025-09-03T13:18:32Z 2019-01-01T00:00:00Z

Title: Test ignore please Authors: test2, test2

2019-01-01T00:00:00Z Goodarzi, Fariborz http://theses.ncl.ac.uk/jspui/handle/10443/3612 2017-09-15T10:38:16Z 1975-01-01T00:00:00Z

Title: Some factors influencing the behaviour of optical properties of carbonised macerals Authors: Goodarzi, Fariborz Abstract: This thesis considers certain factors whose influence on the optical properties of coal macerals heated over a range of temperature and under varying conditions, have not been examined in detail. Reflectivity measurements in two media have allowed derivation of the fundamental optical parameters, refractive and absorptive indices, which, along with bireflectance, have been related to changes in the molecular structure of the heated minerals. The factors studied here are heating rate, prolonged constant heating below the decomposition point, the effect of mixing vitrinites and sporinites before carbonisation, as compared with the optical properties of each maceral carbonised separately, the effect of pressure on carbonised vitrinite and finally heating at elevated temperatures in the range 1000° to 2500°. Description: PhD Thesis

1975-01-01T00:00:00Z Clarke, Edward Leigh http://theses.ncl.ac.uk/jspui/handle/10443/3597 2017-09-14T09:15:21Z 1995-01-01T00:00:00Z

Title: A geochemical study of the controls of crude oil water uptake ability at surface conditions Authors: Clarke, Edward Leigh Abstract: The work contained within this thesis is an assessment of the water uptake ability of various crude oils, and an investigation of the relationship between water uptake and the chemical composition of crude oils. U sing the Karl Fischer titration technique it was possible to achieve rapid analysis of the rate of change of the water content of prepared crude oil/water blends with various added water quantities. A set of procedures, called Crude Oil Water Uptake Analysis (COWUA), were established using this apparatus and applied to a group of crude oils, with varying maturity and extent of biodegradation, from two main oil producing provinces, the U.K. North Sea and Santa Maria Basin, California. Water determination from the top and bottom of crude oil/water blends, combined with visual inspection, was used to characterise the water uptake of crude oils by their water retentive (rate of sedimentation of water and/or emulsion droplets) and emulsion formationl/stabilisation (degree of oil/water separation) abilities. Initial results identified that both of these properties altered with the extent of biodegradation of the crude oil in question. Non-biodegraded crude oils exhibited "poor" water retention (rapid water or emulsion sedimentation) and formed stable water-in-oil emulsions, while degraded crude oils exhibited higher water retentive capability (slower sedimentation) yet possessed varied emulsification ability. Water retention was considered to be possibly due to either the physicochemical (viscosity, density etc.) or geochemical (crude oil compositional) properties of the crude oil. It was anticipated that the composition of crude oils, which exhibit "good" water retention would probably contain "emulsifiers", i.e., asphaltene and wax sols as well as oil-soluble surfactants, such as CO-C3 alkylphenols. These emulsifiers promote stable oil/water interfaces and produce good interaction between the immiscible phases, therefore slowing, or preventing, water and/or emulsion droplet growth. However, bulk chemical analysis showed that the effectiveness of asphaltene and wax emulsifiers decreased with increasing biodegradation and that NSO compounds exhibited no association with increasing water retention. Since no relationship between these crude oil geochemical compositions and increased water retention could be detected it is suggested that physicochemical properties of crude oil/water blends are probably responsible for the rate of sedimentation of the water content. The emulsion formation/stabilisation ability. of crude oils analysed varied. Bulk chemical analysis of the major crude oil chemical groups (aliphatic and aromatic hydrocarbons, resins and asphaltenes) showed that crude oils which formed stable water-in-oil emulsions either possessed a composition conducive to asphaltene and wax precipitation (as for the non-degraded North Sea crude oils) or possessed high NSO contents (as for both non-degraded and biodegraded Santa Maria Basin crude oils). However, where none of the above properties were exhibited, as for biodegraded North Sea crude oils, poor or no emulsion formation occurred. Detailed analysis of the CO-C3 alkylphenols found that their concentration was severely reduced in crude oils which were characterised by poor, or no, emulsification. Therefore, the reduction of oil-soluble surfactants (such as CO-C3 alkylphenols), as well as asphaltene and wax sols, is related to poor emulsion formation! stabilisation. The importance of emulsifiers was further outlined by analysis of the organic matter extracted from the crude oil/water interfacial film present in the emulsions. All the above emulsifiers were found to be preferentially enriched, indicating their involvement in the formation and stabilisation of water-in-oil emulsions. The effect of biodegradation upon water uptake was further investigated under controlled conditions, by the laboratory biodegradation of non-degraded and biodegraded North Sea crude oils. The subsequent emulsification of the non-degraded crude oil during biodegradation was not attributed to the presence of asphaltene and wax sols (biodegradation was considered to reduce the presence of these particles) but the result of significant surfactant generation. This phenomenon is associated with the rapid microbial degradation of the easily metabolisable components in the crude oil. Consequently, the observed lack of emulsification, for the previously biodegraded crude oil, was attributed to both the reduced presence of asphaltene and wax sols, as well as poor surfactant generation associated with slow degradation rates Description: PhD Thesis

1995-01-01T00:00:00Z Gentzis, Thomas http://theses.ncl.ac.uk/jspui/handle/10443/2259 2014-05-30T14:34:52Z 1991-01-01T00:00:00Z

Title: Regional maturity and source-rock potential of palaeozoic and mesozoic strata, Melville Island, Arctic Canada Authors: Gentzis, Thomas Abstract: The thermal maturity and source-rock potential of the Palaeozoic and Mesozoic sediments in Melville Island, Arctic Canada were studied using organic petrology and Rock-Eval pyrolysis. A total of 2,000 polished whole-rock samples were examined and their phytoclast reflectances (% Ro random) measured. In addition, selected samples Were analyzed qualitatively and quantitatively using ultraviolet excitation. Hydrogen-rich organic matter was dominated by alginite (Botryococcus and Iasmanites), dinoflagellate cysts and amorphous fluorescing matrix. Sporinite, cutinite, resinite and liptodetrinite formed the lesser hydrogen-rich organic matter. Vitrinite reflectance in Cretaceous sediments ranged from Ro = 0.36 to 0.65%; in Jurassic sediments it ranged from Ro = 0.40 to 1.0% and in Triassic sediments from Ro = 0.45 to 1.30%. Vitrinite showed an overall increase in %Ro with increasing depth of burial but Variations do occur, possibly due to the effects of mineral matrix (lithology) and liptinite Content. It was observed that when total liptinite percentage was high (20-30%), reflectance was lowered by a magnitude of 0.1 to 0.15%. In addition, the lowering of the reflectance, which was genuine and not experimental, was due to: 1) the effect of bitumen impregnation (staining); and 2) differences in the type of organic matter (hydrogen-rich Vitrinite of marine origin). A large number of shale samples exceeded the worldwide average total organic carbon (TOC) content of 1.05 wt% with the Jurassic-Cretaceous shales and siltstones having higher values than those of Triassic age. The Triassic Schei Point Group shales and siltstones contained organic matter of marine origin, whereas the predominantly Plant-derived organic matter present in the Jameson Bay, Ringnes and Deer Bay formations had a higher TOC. Among the Schei Point Group sediments, the Cape Richards and Eden Bay Members of the Hoyle Bay Formation were richer in TOC (>2.0 wt%) than the Murray Harbour Formation (Cape Caledonia Member), which may reflect differences in the level Of maturity or in the depositional environment (more anoxic conditions for the former). Higher average TOC contents (> 3.0 wt%) were reported in the Cape Richards Member in drill hole Hecla C-32, as well as in the Eden Bay Member in drill holes Hecla C-32, Roche Paint J-43 and North Sabine H-49, all located in Sabine Peninsula. The Schei Point Group sediments contained mainly liptinitic organic matter of marine origin, were Occasionally bitumen stained and have high potential for the generation of liquid hYdrocarbons. Organic matter in the Palaeozoic strata of the Franklinian miogeosyncline was represented mainly by bitumen in the Silurian and Devonian. Different bitumen types Were identified depending on their morphology, reflectance range and association with the enclosing mineral matrix. Thermal maturity of the Palaeozoic strata, based on vitrinite reflectance calculated from bitumen reflectance was high, an indication that the strata Were in the overmature stage of hydrocarbon generation and that only dry gas should be expected. There is petrological evidence that hydrocarbons were generated and Illigrated through the sediments. Regional variations in the level of thermal maturity of Mesozoic sediments in the Sverdrup Basin are a function of burial depth. The Mesozoic formations thicken towards the basin centre (N-NE direction), reflecting the general pattern of increasing thermal maturity north of the Sabine Peninsula. In addition, periods of high heat flow Illost likely existed during rifting episodes from Carboniferous to Early Tertiary. The contour pattern of the regional variation of maturity at the base ofnumerous Triassic formations is similar to that of the structural contours of the Sverdrup Basin, indicating that present-day maturation levels are largely controlled by basin subsidence. Description: PhD Thesis

1991-01-01T00:00:00Z