To continue running our civilization on fossil fuels while avoiding global warming and ocean acidification, anthropogenic carbon dioxide must be diverted from atmospheric release. For geologic carbon sequestration, the injection of CO 2 into the lithosphere, to operate at the necessary large scale requires an understanding of the multiphase flow properties of high-pressure CO 2 displacing brine in porous media. A laboratory-scale core flooding reactor has been built to measure flow properties at in situ pressures, salinities, and temperatures. The reported set of experiments was designed to measure CO 2 relative permeability for CO 2 displacing brine at residual brine saturation. Endpoint drainage CO 2 relative permeability was found to be tightly clustered around 0.35-0.4. These values indicate that CO 2 is not strongly nonwetting, and are characteristic of weakly water-wetting or intermediate wetting flow. Based on these results, CO 2 injectivity will be reduced, pressure-limited reservoirs will have reduced capacity, and inclined area-limited reservoirs will have increased capacity. Future reservoir-scale modeling efforts should incorporate sensitivity to relative permeability. Assuming the majority of reservoirs are pressure limited and if the experimental results reported here are found to apply to other lithologies as well, geologic carbon sequestration at scale will require approximately twice the number of storage sites, wells, reservoirs, and the related infrastructure, personnel, and cost.

This interdisciplinary thesis combines economics and law disciplines in examining the current fiscal regime applicable to upstream petroleum activities in the UK with an overarching objective of developing a policy framework for a new fiscal regime that is not only stable enough to avoid future alterations but also sufficiently fair to balance the unaligned imperatives of the investors and the government. Since the initial days of hydrocarbon exploitation in the UK Continental Shelf the fiscal regime was subject to numerous changes in reaction to the dynamics of the time. Most of these changes were brought about in order to incentivise the investors to explore for and get petroleum while attempting to ensure an appropriate share, or fair return, were accruing to the UK economy. The frequency of these changes however increased fiscal instability, making investment into the UK's upstream sector a riskier proposition. In order to develop a stable regime that can also ensure a fair return, therefore, this thesis begins with a brief overview of the fiscal instability and the government's most recent attempt at ensuring an appropriate share. This most recent attempt, the Treasury's Fiscal Review, is a consequence of the review of the entire upstream industry in the UK by Sir Ian Wood. The resultant report of the review, the Wood Report, provides the government's rationale for reform. Using the government position as a guidance, the work then analyses the conditions under which investors are incentivised and ascertains what exactly is meant by an appropriate share, or fair return, for the state. This analysis is carried out using the relevant investment and fiscal theories which, in turn, yields a set of criteria to evaluate the fiscal instruments. Once the criteria are established they are utilised against the fiscal regime that was in place prior to the government's most recent attempt at receiving a fair return. This is not only to assess the extent of the need for reforming the then existing regime but also to understand what was being reformed. The criteria are then employed subsequently in assessing the same for the most recent reforms of the government.

Petroleum hydrocarbons are emitted into the environment via natural and anthropogenic activities. Once emitted, these hydrocarbons can be transported globally, persisting and accumulating in aquatic ecosystems. In the Alberta oil sands region (AOSR), mining activities have significantly altered and polluted the surrounding aquatic and terrestrial environments with heavy metals and various petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PACs). Though PACs have been tracked through time using dated lake sediment cores, separating natural and anthropogenic PACs can be difficult. In the Peace Athabasca Delta (PAD) this task is especially difficult as this region has been receiving annual inputs of naturally eroded bitumen throughout history. Petroleum biomarkers are unique petrogenic compounds (i.e. derived from petroleum) which may provide a secondary proxy to track mining impacts. This thesis investigated the impacts of mining activities on the AOSR and the PAD using two different proxies, PAC and petroleum biomarkers. These two regions were compared to reference lakes to the south and northwest of the Athabasca oil sands formation, in order to provide a natural signal, with minimal oil sands mining contamination. Historically deposited PACs and petroleum biomarkers were analysed in radiometrically dated lake sediment cores from the AOSR and the PAD, Alberta. Sediment profiles in the AOSR (Saline Lake) showed increases in PAC fluxes for both alkylated and parent compounds coeval with mining activities. Alkylated PAC fluxes in reference lakes (Mariana Lake and BM11) increased at the height of oil sands development (1990s). PAD lakes showed no statistical increase in PAC flux through time due to high levels of naturally eroded bitumen entering the system. Parent PAC diagnostic ratios, however, showed clear shifts from pyrogenic (primarily wood burning) in pre-development sediments to petrogenically derived PACs in modern sediments, in both AOSR and PAD lakes, coeval with oil sands development. Petroleum biomarker diagnostic ratios in Saline Lake and PAD lakes remained stable through time, indicating a clear current and historical petroleum signal originating from the AOSR. Reference lakes (Mariana Lake and BM11) showed the greatest change in petroleum biomarkers. Historically, these lakes had signatures uncommon of petroleum sources, however, in recent years petroleum inputs from mining development were revealed by these petroleum biomarkers. This study compared the historical trends of several petroleum hydrocarbons in lake sediment to the historical emissions of these petroleum hydrocarbons from oil sands mining operations. Notably, we show the potential for petroleum biomarkers to trace petroleum hydrocarbon contamination in the environment.

acase@tulane.edu

The effects of petroleum mulches on the emergence and yield of tomatoes were studied at the Farmington Field Station, Greenville Field Station, North Logan, and the greenhouse. The mulches were applied as surface overlays above the seed or incorporating before plantin. Seedling emergence and yields were measured. Data recorded from trials conducted under cool weather conditions indicated that petroleum mulch overlays can be effective in increasing seedling emergence. The increased seedling emergence with petroleum mulch is due to increased soil temperature , less moisture loss from the surface, and a minimum of soil crust formation.

The effects of petroleum mulches on plant response to herbicides were studied at the Farmington Field Station . The herbicides were applied to the soil preemergent and by incorporation at one-half, normal and double the recommended rates with asphalt overlay. The herbicides and crops used were : Atrazine and Ramrod on sweet corn, PEBC and Diphenamid on tomatoes and EPTC and Trifluralin on snap beans. Germination, overall crop rating, grass and broad leafed weed control and yields were measured. Data recorded from these trials showed that herbicides are as effective under the asphalt when compared to plots with herbicide but no asphalt. Considering all herbicides and conditions, overall crop growth and weed control were not increased or decreased by the asphalt mulch. Germination and yield were not affected by the interaction of herbicides with the asphalt overlay on the three crops.

Competitive reaction in intrazeolitic media is illustrated by the hydroisomerization of hexanes over Pt/Mordenite and Pt/Y, in the presence of an aromatic cofeed. The aromatic inhibits the paraffin reaction, changes the relative reactivities of the different hexane isomers and modifies isomer product distributions. Preferential adsorption by the aromatic modifies catalytic site distributions available for the paraffin reaction, and may also affect diffusional characteristics in the pores of the zeolite Concepts of bifunctional reaction mechanisms and carbenium ion theory are used to explain the mechanism of hexane isomerization and to establish the nature of the reaction network. Based on such mechanistic criteria, the isomer distribution in the presence of an aromatic is rationalized as a consequence of coreactant induced size and shape selectivity modifications to the catalyts The isomerization kinetics are modeled using reaction network analysis to obtain first order rate constants for each individual step of the reaction network. The results indicate that inhibition of the hexane reaction due to the presence of the aromatic affects every step in the reaction network. A generalized framework of transport and reaction in the pores of the zeolite is presented to justify the observed modifications to reaction rates and selectivities / acase@tulane.edu

A suite of samples consisting of twenty-two crude oils and eight sedimentary rocks has been analysed for biological marker compounds by GC-MS. The sedimentary rocks are rich in carbonate minerals and the crude oils were reported to have been derived from carbonate source rocks. These samples are from a variety of geographical origins, geological ages and depositional environments. They consistently contain a homologous series of 30-nor-17 [alpha] (H)-hopanes. Seven homologues (C28 - C34) of the 30-nor-17 [alpha](H)-hopane series have been identified. These compounds appear to be useful biological markers for samples having carbonate associations.A series of 25,30-bisnor-17 [alpha] (H)-hopanes has been observed in a severely biodegraded crude oil of probable carbonate origin. This observation, together with the well-established enrichment of normal hopanes demethylated at position 25 in severely biodegraded crude oils, suggests that the presence of this series of hopanes indicates severe biodegradation of crude oils originating from carbonate-rich source rocks.Another series of hopanes which was previously unreported, the 2-methyl-30-nor-1 [alpha] (H)-hopanes, has also been observed in the carbonate samples. Seven members (C29-C35) of this homologous series have been identified in this study. This series appears to be associated with carbonate rocks deposited under extreme reducing conditions.The biological marker compounds in another sample suite comprising twelve sediments and three crude oils from the North Sumatra Basin, Indonesia, have also been analysed by GC-MS as part of a correlation study. Sediment samples classified as shales, carbonaceous shales and calcareous shales have been shown to contain very different biomarkers. These distinctive biomarkers have enabled the source characteristics of the crude oils to be inferred. Two crude oils have been recognised ++ / with similar biomarker characteristics to the shales and one crude oil has the characteristics of the calcareous shale. The distinctive features of the carbonaceous shale were not observed in the crude oils. This study therefore provides an excellent example of how the 30-nor-17 [alpha] (H)-hopane compounds can be useful in oil-source rock correlation studies.

Two case studies are described where partially biodegraded petroleum residues were collected from the marine environment and analysed to investigate the changes in aromatic hydrocarbons with increasing biodegradation.The first of these studies, involved following the weathering of sea-floor residues from drilling discharges from an offshore petroleum exploration and production platform situated off the coast of North Western Australia. During operations, formation cuttings with adhering oil-based drilling muds were discharged into the ocean via a chute into approximately 125n1 of water, forming a substantial mound at the base of the platform. A suite of seabed sediments was collected from 16 sampling sites at various distances from the platform immediately following the cessation of drilling operations. The distribution of hydrocarbons in the sediment directly under tile cuttings chute was consistent with that found in drilling fluids formulated from a kerosene-like fluid. The samples from more remote sites exhibited the successive enhancement of an unresolved complex mixture relative to the n-alkanes, associated with tile presence of residues from petroleum biodegradation processes. In a subsequent sampling some three years later, a 10 cm core was retrieved from the cuttings pile and divided into 1 cm depth intervals. Samples within 6 cm of the surface of the cuttings pile contained biodegraded residues of the drilling mud, where the extent of biodegradation increased with decreasing proximity to the surface, most likely indicative of aerobic biodegradation. Biodegradation was less evident in the underlying sediments, where anaerobic conditions prevailed. / Analysis of the aromatic hydrocarbons in both sets of sediment extracts by using gas chromatography-mass spectrometry (GC-MS) revealed the successive depletion of alkylnaphthalenes, and due to the subtlety of changes in the extent of biodegradation, provided an excellent opportunity to examine the susceptibility of biodegradation towards the individual alkylnaphthalenes in the marine environment. Conventional GC-MS analysis of these mixtures is performed under chromatographic conditions where complete resolution of the mixture is not achieved and several isomers co-elute. The mass spectra of these co-eluting isomers may be so similar that one is unable to differentiate between them, and their abundance may therefore not be determined. Since each isomer has a unique infrared spectrum, however, the abundance of each individual isomer was determined by comparing the infrared spectrum of the co-eluting compounds with the spectrum of each of the isomers. To this end, techniques were developed for the application of direct-deposition gas chromatography - Fourier transform infrared spectroscopy (GCFTIR) to the analysis of the complex mixture of alkylnaphthalenes present in the petroleum. This technique was also extended to discriminate between individual alkylphenanthrene isomers, and to clarify the sorption behaviour of the dimethylphenanthrenes by mordenite molecular sieves. The identification of other compounds of geochemical significance in petroleum is also described. / Analyses of' the aromatic hydrocarbons in the contaminated sea-floor sediments using GC-FTIR enabled the unambiguous identification and quantification of each of the dimethylnaphthalene, trimethylnaphthalene and tetramethylnaphthalene isomers present in the samples, from which the relative extents of depletion of each with increasing extent of biodegradation were determined. It was apparent from the considerable differences in the observed susceptibility to biodegradation that a strong relationship exists between the compound structure and its susceptibility to biodegradation, with 1,6-disubstituted polymethylnaphthalenes being preferentially depleted relative to other isomers that lack this feature. The second case study involved tracking the fate (weathering) of hydrocarbons from an accidental release of condensate from a buried pipeline into intertidal coastal (mangrove) sediments in North Western Australia. Sediment samples were collected on nine occasions over a three-year period. Chemical analysis of the saturated and aromatic hydrocarbon components of the petroleum extracts revealed that both hydrocarbon fractions exhibited an increasingly biodegraded profile with increased residence time in the sediments. In a similar manner to the first case study, detailed analysis of the aromatic hydrocarbons using GC-FTIR techniques was performed to determine the depletion of individual alkylnaphthalene isomers with increasing extent of biodegradation. It was apparent that a relationship similar to that observed for the sea-floor sediments exists between the alkylnaphthalene structure and its susceptibility to biodegradation. / Changes in the distribution of methylphenanthrene and dimethylphenanthrene isomer mixtures were also studied and the susceptibility to biodegradation amongst these determined in a similar manner. These relative susceptibilities to biodegradation of the aromatic hydrocarbons were then related to the established hierarchy of susceptibilities of the saturated hydrocarbons, in effect providing a second parallel system for the assessment of the extent of biodegradation. Finally, a system of ratios calculated from the relative abundances of selected aromatic hydrocarbons was developed and used as indicators to differentiate between several crude oils that have been biodegraded to varying extents. These parameters also offer promise as indicators of multiple accumulation events in oil reservoirs where petroleum fluids biodegraded to differing extents are mixed.

2D and 3D basin models have been constructed of the southern and central parts of the Vulcan Sub-Basin, which is located in the Timor Sea, north-western Australia. This work was carried out in order to better elucidate the petroleum migration and accumulation histories and exploration potential of the region. The study area extended from the southern limit of the Swan Graben in the south-west to the northern part of the Cartier Trough in the north-east. The results from the basin modelling have been compared with the seafloor bathymetry and physiography, the spatial distributions of hydrocarbon related diagenetic zones (HRDZs) in the region, as well as the distribution of other leakage and seepage indicators. A new method for identifying potential HRDZs using seismic data has also been developed. The 2D/3D modeling results from the Swan Graben indicate that horizontal and downward oil expulsion from the source rocks of the Late Jurassic Lower Vulcan Formation into the upper Plover Formation sandstones was active from the Early Cretaceous to the present day. Oil migration from the Lower Vulcan Formation into the Late Cretaceous Puffin Formation sands in the Puffin Field was simulated via lateral migration along the bottom of an Upper Vulcan Formation seal and by vertical migration above the seal edge. Modelling also indicates that Late Jurassic sequences over the Montara Terrace are thermally immature and did not contribute to the hydrocarbon accumulations in the region. On the other hand, 3D modelling results indicate that the Middle Jurassic Plover Formation in the Montara Terrace became thermally mature after the Pliocene and hence it could have contributed to both the specific hydrocarbon accumulations and the overall hydrocarbon inventory in the area. In the southern Cartier Trough, the Lower Vulcan Formation is typically at a lower thermal maturity than that seen in the Swan Graben, due to a combination of a relatively recent (Pliocene) increased burial and a thinner Lower Vulcan Formation. Here, horizontal and downward oil/gas expulsion from the Lower Vulcan Formation into the Plover Formation sandstone was active from the Late Tertiary to the present day, which is significantly later than the timing of the expulsion in the Swan Graben. In the central Cartier Trough, the areal extent of both generation and expulsion increased as a result of rapid subsidence and deposition from about 5.7 Ma to the present day. This Pliocene loading has resulted in the rapid maturation of the Early to Middle and Late Jurassic source system and expulsion of oil very recently. Oil migration from the Lower Vulcan Formation into the Jabiru structure, via the Plover Formation carrier bed, was simulated in both the 2D and the 3D modelling. In particular, the 3D modelling simulated oil migration into the Jabiru structure, both from the southern Cartier Trough (after the Miocene) and also from the northern Swan Graben (in the Early Cretaceous). Early gas migration, and the attendant formation of a gas cap, was also simulated. Importantly, this result provides a potential alternative interpretation for the formation of at least some of the residual zones in the Timor Sea, as well as in other areas. Traditionally, most of the residual zones within the Timor Sea have been attributed to fault seal reactivation and failure. However, the simulated early gas cap in the Jabiru structure has formed as a result of gas exsolution as the migrating hydrocarbons entered the Jabiru trap (and its shallow flanks), which was then only located a few hundred metres below the surface. The rapidly decreasing pressure allowed the gas to form a separate phase, with the result that in the Early Cretaceous, in the 3D model, the Jabiru trap was composed of a relatively large gas cap with a thinner (“black oil”) oil leg. Progressive burial through the Tertiary, and the attendant increase in pressure, resulted in the gas going back into solution. The associated decrease in the bulk volume of the hydrocarbon accumulation produced a “residual” oil zone at the base of the column, purely through a change in phase, rather than through loss of hydrocarbons from fault seal failure, for example. The processes outlined in this scenario would be essentially indistinguishable from those produced by fault seal failure when assessing traps using fluid history tools such as GOI. Such a process could be critically important in the case of shallow, low-relief traps, where only the exsolved gas could be trapped, with the “black oil” component displaced below the spill of the trap. Small, sub-commercial gas fields would thus be located around the periphery of the source depocentres - though these would be the result of an early, rather than late, gas charge. Small black oil accumulations could be developed inboard from such gas fields. A new method to extract HRDZs from 3D seismic data has predicted the location of new HRDZs in the northern Vulcan Sub-basin. Further investigation is needed to confirm/refine the method but it has the potential to significantly aid HRDZ mapping (and seal assessment and hydrocarbon migration studies). A workflow for future studies is proposed which includes inputs from basin modelling, leakage and seepage mapping, and fault seal and fault reactivation studies. Implementation of this workflow should ultimately allow a more reliable estimation of GOR prior to drilling. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1277632 / Thesis(M.Sc.)-- Australian School of Petroleum, 2007.