Dissertations / Theses on the topic 'Hydrocarbon traps'

This thesis uses high-quality 3D seismic data from the Broad Fourteens Basin (Southern North Sea), Espírito Santo Basin (SE Brazil), and Taranaki Basin (New Zealand) to characterise the evolution of geological structures related to differential compaction and subsidence; also known as subtle hydrocarbon traps. Each chapter tackles deformation over a different geological feature, spanning from salt-withdrawal basins, to submarine channel complexes and associated mass-transport deposits. These chapters subsequently discuss the impact the results have on the hydrocarbon industry. Included in these discussions are the importance of subtle traps on carbon capture and storage, local sealing potential, and reservoir distribution. The Broad Fourteens Basin dataset was used to investigate concentric faults associated with salt withdrawal from below Triassic units. Throw-depth and throw-distance plots helped to understand the growth histories of the concentric faults. It was shown that these faults formed as a result of the bending of strata due to differential subsidence during salt withdrawal. Slip tendency analyses assessed the likelihood for faults to reactivate and transmit fluids whenever pore fluid pressure is increased. This approach simulated a typical profile during carbon capture and storage. It was shown that concentric faults will reactivate if pore fluid pressures are increased above 30 MPa at the relevant sub-surface depths, leaking fluids (including stored CO2) past regional seal intervals in the basin. Data from the Espírito Santo Basin were first used to assess the timing and magnitude of differential compaction over a submarine channel complex. Thickness-relief models helped quantify both the variations in thickness in overburden strata. Smaller channels associated with downslope knickpoints were located within the channel complex. Differential compaction over channels produced four-way dip closures, as coarse-grained sediments were deposited at the knickpoint base. These provide adequate structural traps after early burial. The Espírito Santo Basin 3D survey was used in a third chapter to assess how differential compaction affected sediment distribution over a mass-transport deposit. As large remnant and rafted blocks entrained within the MTD were buried, differential compaction produced anticlines over them. This created a rugged seafloor and the topographic highs confined sediment moving downslope, allowing it to pond in discrete depocentres. Results from the data analysis chapters were compared with compaction-related structures documented in the published literature. A novel classification for subtle structural traps associated with differential compaction was produced, separating each feature into one of four types; Type A: folds over tectonic structures >2 km wide; Type B: folds over sedimentary packages, typically elongate, ~500 m to 5 km wide; Type C: folds over topographic features that are 20 m to 2 km wide; Type D: folds over sub-seismic/outcrop features no larger than 20 m. The results of the classification can be used as a first assessment when recognising a compaction-related fold and to rapidly assess its evolution and effectiveness as a subtle hydrocarbon trap.

The identification and quantification of spin adducts and their reduction products (>NOH, >NOR) formed from nitroso compounds and nitrones in EPR and PP during spin trapping techniques have been examined. The nitroxyl yield and polymer bound nitroxyl percentage formed from these spin traps were found to be strongly dependent on the nature of spin trap and radical generator, processing temperature, and irradiation time. The nitroxyl yield and % bound nitroxyl of the spin traps improved significantly in the presence of Trigonox 101 and 2-0H benzophenone. The effect of these spin traps used as normal additive and their spin adducts in the form of EPR-masterbatch on the photo and thermal-oxidation of PP have been studied. Aliphatic nitroso compounds were found to have much better photo-antioxidant activity than nitrones and aromatic nitroso compounds, and their antioxidant activity improved appreciably in the presence of, a free radical generator, Trigonox 101, before and after extraction. The effect of heat, light and oxidising agent (meta-dichloro per benzoic acid) on the nitroxyl yield of nitroso tertiary butane in solution as a model study has been investigated and a cyclic regenerative process involving both chain breaking acceptor and chain breaking donor process has been proposed.

Using ion-trapping techniques, selected laboratory experiments on ion-molecule reactions of astrophysical interest have been performed. For the first time a carbon beam source has been integrated into an ion trapping machine for studying collisions between ions and neutral carbon atoms and molecules. Results are presented for the interaction of D3+ ions stored in a ring-electrode trap (RET), with a beam of hot neutral carbon molecules, Cn (n = 1, 2, 3). The measured reaction rate coefficients are up to a factor two smaller than values presently used in astrophysical models. In order to complete our knowledge about the ion chemistry involving three carbon atoms, detailed investigations of reactions of C3+, C3H+ and C3H3+ with H2 and HD have been performed between 15 K and room temperature. These studies have been performed in a second apparatus, a variable-temperature 22-pole trap machine (VT-22PT). Results include reactive collisions, deuteration and radiative association. It is discussed in connection with the increase in lifetime of the C3+ + H2 collision complexes with falling temperature, what could be responsible for producing more C3H+ at 15 K. Tunneling is excluded. In C3+ + HD collisions an isotope effect has been detected, the C3D+ product ions being slightly more abundant than C3H+. Comparison of the reaction of C3H+ primary ions with HD and H2 gas revealed that the deuterated molecules are significantly more reactive. The process of radiative association of C3H+ and for the first time of C3+ with hydrogen molecules has been observed. An analysis of the data shows that radiative association becomes slower, if the neutral reactant is deuterated. Finally, the theoretical prediction from ab initio calculations that C3H3+ does not exchange an H for a D in collisions with HD, has been proven in an ion trap experiment. Careful analysis of all competing processes allows the conclusion that the rate coefficient is smaller than 4x10-16 cm3s-1 at 15 K
Unter Verwendung von zwei Speicherapparaturen wurden ausgewählte, astrophysikalische wichtige Ionen-Molekülreaktionen untersucht. Durch die Kombination einer Kohlenstoffquelle mit einem Ionenspeicher, in dem so Reaktionen zwischen Ionen und Kohlenstoffmolekülen oder -atomen untersucht werden können, wurde Neuland betreten. Es werden Ergebnisse vorgestellt für die Reaktion von D3+ Ionen, die in einem Ringelektrodenspeicher gefangen sind, mit einem Strahl von heißen Cn (n = 1, 2, 3). Die gemessenen Ratenkoeffizienten sind nur halb so groß wie die Werte, die in astrophysikalischen Modellen verwendet werden. Um die Kenntnis über alle möglichen Reaktionen, bei denen drei C-Atome beteiligt sind, abzurunden, wurden zwischen 15 K und Zimmertemperatur die Reaktionen zwischen C3+, C3H+ und C3H3+ Ionen mit H2 und HD in vielen Details untersucht. Diese Experimente wurden in einer zweiten Apparatur durchgeführt, in der ein temperaturvariabler 22-Polspeicher das zentrale Element ist (VT-22PT). Berichtet werden Ergebnisse zu reaktiven Stößen, zur Deuterierung von Kohlenwasserstoffen und zur Strahlungsassoziation. In der Diskussion bleibt offen, was - in Verbindung mit der von 300 K zu 15 K zunehmenden Lebensdauer - der Grund dafür sein kann, daß die Bildung des exothermen Produkts C3H+ anwächst. Der Tunneleffekt scheidet aus. Bei der Reaktion C3+ + HD wurde ein Isotopeneffekt beobachtet, das C3D+ Produkt wird etwas häufiger gebildet als C3H+. Ein Vergleich der Reaktion zwischen C3H+ Ionen mit HD bzw. H2 zeigt, daß das deuterierte Molekül wesentlich reaktiver ist. Es wurden Ratenkoeffizienten für die Strahlungsassoziation von H2 Molekülen mit C3H+ und erstmals mit C3+ Ionen gemessen. Die Auswertung der Daten zeigt, dass der Prozeß langsamer abläuft, wenn der neutrale Stoßpartner deuteriert ist. Schließlich wurde experimentell die theoretische Vorhersage überprüft, dass C3H3+ keinen H-D Austausch mit HD eingeht. Eine sorgfältige Analyse aller konkurrierenden Prozesse ergab, dass bei 15 K der Raten koeffizient kleiner als 4x10-16 cm3s-1 ist

Understanding thickness variation and facies transitions in the mudstone-rich part of the Upper Middle Jurassic (Callovian) Entrada Sandstone depositional system is critical for constraining the paleogeography and evaluating the economic potential of Utah's Entrada Sandstone. Facies of the Entrada Sandstone in south-central Utah are dominated by mudstone-rich intertidal facies that were widespread within the Jurassic seaway. Intertidal deposits interfinger basinward with subtidal ooid-bearing shoals and bars, and landward supratidal sabkha, and erg-margin eolian deposits. Three sections were measured to improve understanding of the lateral and vertical facies transitions. Variations in thickness indicate the rate of developing accommodation space was high along the southwestern shoreline and relatively low along the northeastern shoreline during Callovian time. Although accommodation space was highest in the west, sediment supply from the west kept pace with, and eventually outpaced subsidence. In the east, sediment supply was significant but at one time was outpaced by subsidence, creating a complete range of facies, from subtidal to supratidal deposits. Along this eastern shoreline, erg-margin coastal dunes associated with the larger erg to the east eventually prograded westward. The variation in subsidence, sediment supply, and sediment source makes sequence stratigraphic correlation difficult. Reservoir-quality sandstones are associated with muddy sections of the Entrada Sandstone within the San Rafael Swell. Porosity and permeability of the facies in this area indicate excellent reservoir potential in three of eight facies that were studied. Porosities of these potential reservoirs ranged from 11-22%, with permeabilities ranging from 44-430md. These high quality reservoir facies are surrounded by muddy, low reservoir-quality rocks, creating conditions amenable to the development of stratigraphic hydrocarbon traps. Based on further study and a modern analog at the north of the Gulf of California, Hicks and others' (2010) depositional model for the Entrada Sandstone of south-central Utah has been modified to include newly interpreted facies. This improved depositional model may have predictive power in exploring for stratigraphic and combination traps within the Entrada system of Utah and analogous depositional systems throughout the world.

The late Middle Jurassic (Callovian) Entrada Sandstone has been divided into two general facies associations consisting primarily of eolian sandstones in eastern Utah and "muddy" redbeds in central Utah. Sedimentary structures within the redbed portion are explained by the interfingering of inland sabkha, alluvial, and eolian depositional systems. A complete succession from the most basinward facies to the most terrestrial facies in the Entrada Sandstone consists of inland sabkha facies overlain by either alluvial or eolian facies. Where both alluvial and eolian facies interfinger, alluvial facies overlain by eolian facies is considered a normal succession. Sequence boundaries, often identified by more basinward facies overlying more landward facies, are observed in the Entrada Sandstone and are extrapolated for the first time across much of Utah, including both the eolian-dominated and redbed-dominated areas. Using these sequence boundaries as well as recent tephrochronologic studies, three time correlative surfaces have been identified in the Entrada. Based on the facies interpretations at each surface, five paleogeographic reconstructions and five isopach maps have been created, illustrating two major intervals of erg expansion and the location of the Jurassic retroarc foreland basin's potential forebulge. Eolian (erg-margin) sandstones pinch-out into muddy redbeds creating combination traps, as evidenced by dead oil (tar) and bleached eolian sandstone bodies within the Entrada. The Entrada Sandstone is a world-class analog for similar systems, such as the Gulf of Mexico's Norphlet Sandstone, where eolian facies grade into muddy redbed facies.

The East Shetland Basin is a superb natural laboratory in which to study the role that normal fault growth and linkage has in determining petroleum prospectivity. Use of several high density 3D seismic volumes and over 250 boreholes permits key aspects of the Late Jurassic rift and its Permo-Triassic precursor to be analysed and its role on hydrocarbon trap formation, reservoir distribution and migration determined. The regional interpretation has revealed the generation of a North Sea archipelago of Upper Jurassic islands, the role of relay ramps in controlling syn-rift sediment dispersal patterns and the impact of normal faults of the later episode crossing and offsetting those generated by the earlier phase. The uplift, erosion and meteoric flushing of Upper Jurassic and older strata within the exposed fault blocks could potentially have huge consequences for the Brent play by enhancing reservoir properties and hence, help identify new play opportunities down-dip of major structures. Fault control on sediment dispersal can also be documented in a more localized study on the Cladhan Field, the site of a pronounced basin-margin relay ramp. This recent discovered set of syn-rift density flows illustrates how the development and distribution of depositional gradients and transport pathways form subtle play types. The Cladhan area is just one of several locations throughout the East Shetland Basin where the interaction of multiple rift phases is influential in the structural feedback after the Upper Jurassic rifting event. The delicate interaction and reactivation of underlying structural trends creates a series of multi-tiered fault block systems which can define several aspects of a petroleum system, depending upon the strike, polarity and level of reactivation of faults from one rift to another. The observations of fault growth and linkage in the Northern North Sea may provide generic lessons that help in determining petroleum prospectivity in other hydrocarbon rift basins (e.g. E. Africa and the N. Atlantic seaboard of North America).

Thesis (Ph. D.)--Georgia State University, 2006.
Title from title screen. George E. Pierce,committee chair; Eric S. Gilbert, Sidney A. Crow, committee members. Electronic text (135 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Aug. 20, 2007. Includes bibliographical references (p. 120-124).

Les hydrocarbures aromatiques polycycliques (HAP) sont des molécules carbonées de grande taille dont l'étude intéresse différents champs disciplinaires qui vont de l'environnement à l'astrochimie. Constituant majeur de la poussière cosmique, elles jouent un rôle clé dans les régions de formation stellaire, où leur émission infrarouge est excitée par les photons ultraviolets. Les mécanismes impliqués dans leur formation restent néanmoins mal connus. Dans les expériences de simulation en laboratoire comme dans les météorites, la masse m/z = 202.08 correspondant à l'espèce C_16H_10, a été identifiée comme une espèce clé dans la croissance de ces HAP. Cette espèce comprend plusieurs structures isomériques qu'il est important de pouvoir différencier. Nous avons utilisé l'analyseur moléculaire AROMA pour étudier la différentiation des isomères de C_16H_10 par dissociation induite par collisions (CID), dans le cas du fluoranthène et du pyrène (structures compactes) et celui du 9-éthynylphenanthrène (structure avec un groupe alkyl). Les différents paramètres contrôlant la CID ont été explorés afin de déterminer des conditions optimisées pour notre dispositif expérimental. A basse énergie de collision, nous avons montré que le critère de 50 % de dissociation des ions parents peut être utilisé pour différencier les structures condensées des non condensées et plus difficilement pour différencier les structures condensées entre elles. La procédure a été appliquée sur des espèces individuelles, leurs mélanges et des échantillons plus complexes de météorite (Allende) et d'analogues en laboratoire de poussière cosmique (plasma poussiéreux). Nous avons modélisé la dynamique des ions dans le piège et extrait des distributions de fréquence et d'énergie de collisions. La compétition avec le taux de dissociation a été traitée par méthode Monte Carlo. L'ajustement par le modèle de la courbe de dissociation du pyrène a permis de quantifier le paramètre de transfert d'énergie cinétique en énergie interne. La courbe de dissociation du fluoranthène a pu être modélisée en utilisant les mêmes valeurs pour êta. Enfin nous avons pu déterminer le taux de dissociation du 9-éthynylphenanthrène, qui n'est pas connu à ce jour
Polycyclic aromatic hydrocarbons (PAH) are large carbonaceous molecules that are the subject of investigation in various fields from astrochemistry to environmental science. Being a major constituent of cosmic dust, they play a key role in regions of star formation, where their infrared emission is excited by ultraviolet photons. However, the mechanisms involved in their formation remain poorly understood. In simulation experiments in the laboratory as in meteorites, the mass m/z = 202.08 corresponding to the species C_16H_10, has been identified as a key species in the growth of these PAHs. This chemical formula includes several isomeric structures that need to be differentiated. We used the AROMA molecular analyzer to study the differentiation of C_16H_10 isomers by collision-induced dissociation (CID), in the case of fluoranthene and pyrene (two compact structures) and that of9-ethynylphenanthrene (structure with an alkyl group). The various experimental parameters control-ling the CID were explored in order to determine optimized conditions for our experimental conditions. At low collision energy, we have shown that the criterion of 50 % dissociation of parent ions can be used to differentiate condensed from non-condensed structures but is more difficult to differentiate between condensed structures. The procedure has been applied to individual species, their mixtures, and more complex samples of meteorite (Allende) and laboratory analogues of cosmic dust (dusty plasma). We have modeled the dynamics of the ions in the trap and extracted frequency and energy distributions of collisions. The competition with the dissociation rate was treated by Monte Carlo method. The model fit of the pyrene dissociation curve quantified the parameter êta of transfer of kinetic energy into internal energy. The fluoranthene dissociation curve could be modeled using the same values for êta. Finally, we were able to determine the dissociation rate of 9-ethynylphenanthrene, which is not yet known

A new depth-based method of seismic imaging is used to provide insights into the 3D structural geometry of faults, and to facilitate a detailed structural interpretation of the Penola Trough, Otway Basin, South Australia. The structural interpretation is used to assess fault kinematics through geological time and to evaluate across-fault juxtaposition, shale gouge and fault reactivation potential for three selected traps (Zema, Pyrus and Ladbroke Grove) thus providing a full and systematic assessment of fault seal risk for the area. Paper 1 demonstrates how a depth-conversion method was applied to two-way time seismic data in order to redisplay the seismic in a form more closely representative of true depth, here termed ‘pseudo-depth’. Some apparently listric faults in two-way time are demonstrated to be planar and easily distinguishable from genuine listric faults on pseudo-depth sections. The insights into fault geometry provided by pseudo-depth sections have had a significant impact on the new structural interpretation of the area. Paper 2 presents the new 3D structural interpretation of the area. The geometry of faulting is complex and reflects variable stress regimes throughout structural development and the strong influence of pre-existing basement fabrics. Some basement-rooted faults show evidence of continual reactivation throughout their structural history up to very recent times. Structural analysis of all the live and breached traps of the area demonstrate that traps associated with a basement rooted bounding fault host breached or partially breached accumulations, whereas non-basement rooted faults are associated with live hydrocarbon columns. Papers 3 and 4 demonstrate that for all the traps analysed (Zema, Pyrus and Ladbroke Grove), initial in-place seal integrity was good. The initial seal integrity was provided by a combination of both favourable across fault juxtaposition (Ladbroke Grove) and/or sufficiently well developed shale gouge over potential leaky sand on sand juxtaposition windows to retain significant hydrocarbon columns (Zema, Pyrus). The palaeocolumns observed at Zema and Pyrus indicate that there has been subsequent post-charge breach of seal integrity of these traps while Ladbroke Grove retains a live hydrocarbon column. Evidence of open, permeable fracture networks within the Zema Fault Zone suggest that it is likely to have recently reactivated, thus breaching the original hydrocarbon column. Analysis of the in-situ stress tensor and fault geometry demonstrates that most of the bounding faults to the selected traps are at or near optimal orientations for reactivation in the in-situ stress tensor. The main exception being the Ladbroke Grove Fault which has a NW-SE trending segment (associated with a relatively high risk of fault reactivation and possible leakage at the surface) and an E-W trending segment (associated with a relatively low risk of fault reactivation and a present day live column). The free water level of the Ladbroke Grove accumulation coincides with this change in fault orientation.
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Thesis (Ph.D.) - University of Adelaide, Australian School of Petroleum, 2008

Crude oil is a mixture of hydrocarbons so complex that it is predicted to comprise as many compounds as there are genes in the human genome. Developing methods to not only recover crude oil from the ground but also to convert crude oil into desirable products is challenging due to its complex nature. Thus, the petroleum industry relies heavily on analytical techniques to characterize the oil in reservoirs prior to enhanced oil recovery efforts and to evaluate the chemical compositions of their crude oil based products. Mass spectrometry (MS) is the only analytical technique that has the potential to provide elemental composition as well as structural information for the individual compounds that comprise petroleum samples. The continuous development of ionization techniques and mass analyzers, and other instrumentation advances, have primed mass spectrometry as the go-to analytical technique for providing solutions to problems faced by the petroleum industry. The research discussed in this dissertation can be divided into three parts: developing novel mass spectrometry-based methods to characterize mixtures of saturated hydrocarbons in petroleum products (Chapters 3 and 5), exploring the cause of fragmentation of saturated hydrocarbons upon atmospheric pressure chemical ionization to improve the analysis of samples containing these compounds (Chapter 4), and developing a better understanding of the chemical composition of crude oil that tightly binds to reservoir surfaces to improve chemically enhanced oil recovery (Chapter 6).