bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Near-Seafloor 3D Seismic Data in Deepwater Exploration and Production
Authors: Steffens G.S. , Shipp R.C. , Prather B.E. , Nott J.A. , Gibson J.L. , Winker C.D. 
Published: April 2008

Abstract
The analysis of 3D seismic data in the near-seafloor interval is a useful speciality in deepwater exploration and production. In addition to the well-established benefits of 3D seismic data, the higher frequency content of near-seafloor data has a variety of applications throughout the life cycle of deepwater plays. These benefits include: (1) depositional process modelling, (2) stratal architectural information for building reservoir models, and (3) drilling hazard assessment.
Detailed mapping of well-imaged 3D seismic intervals in the near-seafloor interval is providing new insights to deepwater depositional processes and architectures. Depositional patterns are more confidently identified in near-seafloor settings, enabling the investigation of testable relationships between stratal stacking patterns, gradient changes and accommodation. These relationships as well as spatial and geometric information from these data are useful for building and constraining reservoir models, linking key observations from subsurface data at prospective levels with fine-scale outcrop analogue data. In particular, near-seafloor 3D data can image surfaces related to episodes of aggradation, starvation, bypass, and/or erosion that are typically hard to recognize or map at exploration depths, but are critical in controlling reservoir bed-length and connectivity in three dimensions. Near-seafloor 3D seismic data can supplement or even replace traditional 2D-based site surveys for assessing potential drilling hazards. Although usually lower in vertical resolution than 2D site survey data, 3D data have the distinct advantage of better imaging of 3D geometric bodies, providing insight into complex stratal stacking patterns, and allowing data volume manipulation and perspective.
Structural Controls on the Positioning of Submarine Channels on the Lower Slopes of the Niger Delta
Authors: Morgan Richard 
Published: April 2008

Abstract
Recently acquired 2D seismic data shot over the western Niger Delta have enabled a pre-delta rift framework to be delineated inshore of a transform fault dominated continental margin which lies beneath the later, delta sediment apron. The delta apron has been deformed by toe-of-slope thrusting where faults have climbed from a detachment surface at or near the top of the over-pressured Akata Formation mudstones. The overlying mixed clastic succession of the Agbada Formation has been faulted by a broadly oceanward stepping series of NW-SE trending thrusts climbing from this detachment level. The principal thrusts have been offset by NE-SW trending transfer zones, the positions of which have been inherited from trends within a pre-delta rift framework that underlies part of the western delta slope.
3D seismic data partly covering the 2D grid show turbidite channel complexes at numerous stratigraphic levels within the Agbada Formation and clustered in particular areas of the slope. Commonly, submarine channels can be seen to have cut through the relief caused by folding at the positions of intersection with transfer fault zones. These data show the relationship between structure and channel formation and highlight the importance of transfer fault zones in localizing channel systems on the lower slope. Nevertheless, the 2D seismic data has provided an explanation for the location of the transfer zones within the toe-thrust belt in the form of an underlying structural framework, and both data types have contributed to the understanding of controls on reservoir distribution in an area where the principal sand delivery systems are perpendicular to the main structural trend.
3D Anatomy of Late Neogene Contourite Drifts and Associated Mass Flows in the Faroe-Shetland Basin
Authors: Knutz Paul C. , Cartwright Joseph A. 
Published: April 2008

Abstract
We have combined 3D mapping of key reflectors with seismic profiles to describe the geometry and anatomy of contourite drifts formed by deep waters passing through the oceanic gateway of the Faroe-Shetland Channel. The West Shetland Drift complex is characterized by sheeted-mounded drift units, and upslope migrating sediment waves accreting over an early Pliocene unconformity. The basin section is constructed by a series of asymmetric depositional units of early Pliocene-Pleistocene age, interlayered by three mega-debrite sequences that extend into the basin. The Pliocene drift surface display an enhanced topography of bifurcating moat-channels that tend to branch out in a southwest direction. Along the lower slope a succession of upslope migrating sediment waves has accumulated from the Pliocene drift topography. These features extend to the present sea bed at water depths of 700-1000 m where they appear as a series of linear, bifurcating ridges. The high accumulation rates of the West Shetland Drift since the early Pliocene transition and the formation of upslope migrating sediment waves is related to a sustained flow of Norwegian Sea deep waters and cross-slope transport of fine-grained sediments from the NW European shelf.
Interactions between Topography and Channel Development from 3D Seismic Analysis: an Example from the Tertiary of the Flett Ridge, Faroe-Shetland Basin, UK
Authors: Robinson Andrew M. , Cartwright Joseph A. , Burgess Peter M. , Davies Richard J. 
Published: April 2008

Abstract
Interpretation of 3D and 2D seismic data in the Faroe-Shetland Basin (FSB) has revealed the important role that structurally controlled bathymetry had in controlling sedimentary dispersal during Early Cenozoic thermal subsidence. The Flett Ridge was a major NE-SW structural high during some of the Palaeogene, actively growing and influencing adjacent sedimentary systems. During the Palaeogene this area of the FSB was a key entry point for siliciclastic sediment with a major deltaic system prograding towards the NW during the Middle Eocene. Prior to delta development, the Flett Ridge was onlapped during the Late Palaeocene and subsequently blanketed and drowned in Early Eocene times. Major periods of fluvial incision cutting up to 100 m into the Middle Eocene strata are identified and a variety of channel networks with differing trends documented. Broad channels or valleys of earliest Middle Eocene age inherited the palaeotopography created by the Flett Ridge, whereas subsequent later Middle Eocene meandering channels trend perpendicular to the shelf edge and traverse the Flett Ridge structure. Seismic amplitude maps suggest that a complex and variable channelized drainage system developed across the coastal plain and delta top in the Middle Eocene. These channels influenced sediment supply creating an area of bypass to the more distal fan systems preserved at the base of slope. Later faulting on the ridge crest may also have affected the channel network pattern.
The Evolution and Growth of Central Graben Salt Structures, Salt Dome Province, Danish North Sea
Authors: Rank-Friend Malene , Elders Christopher F. 
Published: April 2008

Abstract
The remarkable spatial resolution of 3D seismic data is particularly important in the study of salt structures, where changes in the distribution of accommodation space resulting from salt withdrawal can be mapped and related to the evolution of the individual salt structures. The Salt Dome Province of the Danish Central Graben provides an interesting example of this approach. Three adjacent salt structures (Skjold, Dan and Kraka) exhibit very different geometries, and their evolution has been the subject of some debate. The present study suggests that the Dan structure is composed almost entirely of Zechstein salt, which, facilitated by de-coupled extension during the Mid-Late Jurassic, has been intruded into and along weak planes of Triassic salt, resulting in an overall domal, circular outline. Skjold is located to the NW of Dan. It consists of Zechstein salt and forms a mature salt stock, which terminates within Upper Cretaceous strata. Skjold evolved from a linear NW-SE trending salt wall and became a point source structure during the Early Cretaceous, in common with the many other Central Graben diapers and coincident with the commencement of thermal subsidence. By contrast, Kraka, a NW-SE trending pillow structure located to the south of the Dan-Skjold alignment never became diapiric. Gravitational downbuilding of the mature Skjold diapir during rapid Cenozoic deposition was punctuated by rejuvenated (active) growth induced by regional compression, most significantly during the Mid-Miocene. This event affected also the Dan and Kraka structures, which otherwise experienced very limited growth during the Cenozoic.
Integrating 3D Seismic Data with Structural Restorations to Elucidate the Evolution of a Stepped Counter-Regional Salt System, Eastern Louisiana Shelf, Northern Gulf of Mexico
Authors: Trudgill Bruce D. , Rowan Mark G. 
Published: April 2008

Abstract
By integrating 3D and 2D seismic interpretation with structural restorations we have reconstructed the evolution of a complex, composite stepped counter-regional salt system in the West Delta/South Pass (WDSP) area of the northern Gulf of Mexico. Biostratigraphically calibrated well data allow the last 10 Ma of the evolution of the salt system to be divided into six stages: (1) sea-floor extrusion of isolated salt tongues fed from the Jurassic Louann salt through northward dipping feeders prior to 7.5 Ma; (2) amalgamation of the salt tongues to form a salt-tongue canopy between 7.5 and 6.4 Ma; (3) counter-regional evacuation of the salt-tongue canopy as a result of enhanced sediment loading due to progradation of the shelf margin between 6.4 and 5.0Ma; (4) evacuation of salt into a series of salt walls linking salt domes between 5.00 and 2.55 Ma; (5) evacuation of the salt walls to form counter-regional fault welds between 1.95 and 0.5 Ma; and (6) final evacuation of most of the salt from deeper levels leaving a series of isolated salt domes connected by counter-regional fault welds. The counter-regional evacuation of the WDSP salt systems illustrates the value and limitations of published 2D models for allochthonous salt, and the reconstructed evolution yields insights into the complex interactions between salt deformation and sedimentation. The results also suggest that the WDSP salt systems significantly affected sediment transport pathways, trap geometries and possibly late stage petroleum migration across evacuating salt welds.

Supplementary material:
Three movies depicting the 2D and 3D restorations and models are available at
https://doi.org/10.6084/m9.figshare.c.4784595
Exploration 3D Seismic over the Gjallar Ridge, Mid-Norway: Visualization of Structures on the Norwegian Volcanic Margin from Moho to Seafloor
Authors: Corfield S. M. , Wheeler W. , Karpuz R. , Wilson M. , Helland R. 
Published: April 2008

Abstract
We present an analysis of a unique 3D survey that allows us to relate the deep structure of the crystalline crust to the shallow structure of the overlying, potentially hydrocarbon-rich sedimentary basins. The survey is located over the Gjallar Ridge, Mid-Norway, and extends from a Moho-level reflector at around 15 km depth to polygonal faulting and diapiric structures at or near the seabed. 3D visualization techniques using seismic workstations and the Cave immersive environment have been used to illustrate the geometries of these features. The deep reflector is correlated with the top of a deep, high-density, high-velocity body that is interpreted to indicate the presence of magmatic underplating and is intimately related to localized uplift of the Gjallar Ridge. Abundant high-amplitude reflectors in the deep Cretaceous sections of the survey are interpreted as sills emplaced during the Palaeocene magmatic event and are therefore interpreted to be coeval with the magmatic underplate. In contrast, the shallow parts of the survey have numerous gas-charged mud diapirs and an extensive network of polygonal faults extending to the seabed. Study of such very deep or very shallow features is not standard industry practice. However, the intention here is to demonstrate that, by utilizing the full volume of 3D seismic data, it is not only of scientific interest but also results in a greater understanding of the tectonic history of a hydrocarbon prospect.
Visualization and Interpretation of 3D Seismic in the Carboniferous of the UK Southern North Sea
Authors: Lynch Jeremy J. 
Published: April 2008

Abstract
Examples from the Carboniferous of the UK Southern North Sea are used to illustrate the application of visualization tools to increase the effectiveness of 3D seismic interpretation. Maintaining the seismic data to the fore throughout the interpretation workflow and decision-making process is vital for well planning in field development and trap validation in prospect evaluation. Scaling of the seismic into the 'true-depth' domain and the automatic generation and visualization of layers using isochores derived from well data are the key elements in this interpretation workflow. Together these allow full integration of the seismic with various well data and interpreted elements. The main example is from Murdoch K, one of ConocoPhillips's most recent UK discoveries, part of a pre-Permian extensional graben inverted during the Early Tertiary tectonic phase. Other examples from the McAdam Field and an exploration prospect are used to highlight additional aspects of the method.
Direct Visualization and Extraction of Stratigraphic Targets in Complex Structural Settings
Authors: James Huw , Bond Rob , Eastwood Lucy 
Published: April 2008

Abstract
Advances in 3D visualization and volume detection have greatly improved our ability to find stratigraphic targets in areas of complex structure. In this paper we apply volume sculpting, seismic facies analysis and prediction of rock properties from seismic data to resolve a potential reservoir channel from a highly faulted setting in offshore Indonesia. These techniques use computational power to search for patterns in the data. These patterns may be presented to the interpreter or may be used to transform seismic and well data into estimates of rock properties. Such techniques should improve development efficiency in areas where complex structure has previously precluded the use of these techniques.
4D/Time-Lapse Seismic: Examples from the Foinaven, Schiehallion and Loyal Fields, UKCS, West of Shetland
Authors: Bagley G. , Saxby I. , McGarrity J. , Pearse C. , Slater C. 
Published: April 2008

Abstract
4D or time-lapse seismic data has become a business of usual tool for reservoir management in high-cost environments for oil production such as the West of Shetlands. 4D seismic can be used to visualize fluid movement in a qualitative/semi-quantitative sense to visualize field behaviour, predict well performance and predict reservoir pressure. Whilst the data may be easily visualized using 3D visualization technology the challenges for the future include the need to obtain quantitative predictions through better quality seismic data.

Supplementary material:
Ten movies showing 3D and 4D seismic data are available at
https://doi.org/10.6084/m9.figshare.c.4784616
Modelling Fault Geometry and Displacement for very Large Networks
Authors: Lister Dustin L. 
Published: April 2008

Abstract
Traditional methods for building fault models are time-consuming when applied to a complex fault network or where many faults exist since the workflows typically rely on manual intervention at several stages. Structural detail is often simplified to reduce cycle times and consequently, the workflow favours large-scale and simplistic fault systems. There is generally no integrated assessment of kinematic information that would be useful in guiding fault interpretation. A new methodology for constructing a complex fault network with small offset is presented. The method recognizes that interpretation of large numbers of interconnected low displacement faults, is most efficiently done using map based interpretations. A novel semi-automated skeletonization algorithm is used to extract fault traces from horizon maps providing a polyline data set for subsequent use in 3D surface creation. Displacement information is derived automatically during or after the skeletonization providing kinematic information for guiding further interpretation. The new method is validated against manual interpretations of fault geometry and displacement before application to a region of the Central North Sea exposing polygonal faults. The new technique allows for the first time, a rapid and accurate appraisal of complex near-seismic scale fault geometry and displacement from interpretations of 3D seismic data across a large survey area.
Neoproterozoic, passive-margin, sedimentary systems of the Kanin Peninsula, and northern and central Timan, NW Russia
Authors: Roberts David , Siedlecka A. , Olovyanishnikov V. G. 
Published: April 2008

Abstract
Neoproterozoic, slope-to-basin, lithostratigraphic successions are discontinuously exposed within the Timan Range, in NW Russia, NE of a faulted basinal margin that marks the outer edge of a former, fluvial to shallow-marine, pericratonic domain. The Mid to Late Riphean, deep-water depositional systems of the Kanin Peninsula, and northern and central Timan attain considerable thicknesses, up to 10 000 m in the case of Kanin Peninsula. Basements to these successions are nowhere exposed. Although the successions accumulated along a comparatively stable, passive margin of Baltica, there are notable differences in sedimentary facies from area to area. Whereas the successions in northern and central Timan preserve a record of relative stability, with sedimentation keeping pace with subsidence, the nearby Kanin succession shows evidence of repeated faulting. This may reflect a non-contemporaneity of the diverse successions or a segmentation of the basin margin. Comparisons are also made with deep-water, turbidite-fan systems in northwestern parts of the Timan-Varanger Belt, on the Rybachi and Varanger Peninsulas. The lateral differences in sedimentary facies in these areas, seen in relation to the situation in Timan and Kanin, do, in fact, suggest that the 1800 km long Timanian Basin margin may have been segmented, and possibly into sub-basinal domains.
Late Neoproterozoic sedimentation in the Timan foreland
Authors: Grazhdankin D. 
Published: April 2008

Abstract
The late Neoproterozoic Vendian succession fills a peri- to epicratonic Mezen Basin in front of the Timan Orogen, and is exposed along the northwestern flank of the basin. In the SE White Sea area, the siliciclastic succession demonstrates a wide range of lithofacies that define a transition from a low-energy shallow-marine muddy shelf to a braid-delta plain. Significantly, the prodelta, distributary-mouth bar, and delta plain lithofacies all demonstrate a remarkably tight clustering of palaeocurrent trends suggesting that the sediment was sourced from the NE. This pattern is interpreted as representing deposition in a distal setting in the Timan foreland basin. U-Pb zircon dates of 558 ± 1 Ma and 555.3 ± 0.3 Ma for volcanic tuffs in the Vendian succession provide lower age constraints for the emergence of the Timanian hinterland.
The Vendian alkaline igneous suite of northern Timan: ion microprobe U-Pb zircon ages of gabbros and syenite
Authors: Larionov Alexander N. , Andreichev V. A. , Gee D. G. 
Published: April 2008

Abstract

Near the Barents Sea coast in northern Timan, turbidites of probable Neoproterozoic age are intruded by pre-tectonic dolerites and a major suite of gabbros, granites and syenites (some nepheline bearing). Zircon ion microprobe dating of three plutons has yielded well-defined ages of 613–617 Ma. This alkaline igneous activity apparently represents a final phase of Vendian extensional magmatism prior to Timanian Orogeny. Previous work on late to post-orogenic calc-alkaline granites in the basement beneath the Pechora Basin, three hundred kilometres towards the SE, has yielded
c.
550–560 Ma single zircon Pb-evaporation ages. These compositionally different intrusive suites are inferred to constrain the main phase of Timanian Orogeny to
c.
610–560 Ma.
Timanian blueschist-facies metamorphism in the Kvarkush metamorphic basement, Northern Urals, Russia
Authors: Beckholmen Monica , Glodny Johannes 
Published: April 2008

Abstract

The core of the Kvarkush Anticline, on the western side of the Northern Urals, contains pre-Ordovician metasediments and minor metabasites that have undergone multistage deformation and transitional greenschist- to blueschist-facies metamorphism. Metamorphic conditions for the blueschist-facies assemblages are estimated at 350–400 °C and 7–8 kbar. The metamorphic rocks are cut by mafic dykes, one of which yields a Sm-Nd mineral age of 398 ± 37 Ma (2σ). The age of the high-pressure/low-temperature (
HP/LT
) metamorphism has been controversial. New Rb-Sr mineral data yield ages for the waning of blueschist-facies metamorphism at
c.
536 Ma (535 ± 6 Ma, 535.8 ± 6.5 Ma, 536 ± 19 Ma, all 2σ), demonstrating that the specific conditions required for blueschist-facies metamorphism were attained in latest Neoproterozoic to earliest Cambrian times. The new data are the first well-constrained documentation of
HP/LT
metamorphism within the Timanian Orogen. We suggest that easterly-directed subduction of the East European continental margin (present-day coordinates) during the Timanian Orogeny, involving compressional thickening of the margin sediments, is the most likely scenario for the formation of the Kvarkush blueschists. The Kvarkush
HP/LT
metasediments, together with lower greenschist-facies and subgreenschist-facies metasediments further west, form parts of a Timanian orogenic wedge on an east-dipping thrust ramp. Reworking during the Uralian orogenesis was of minor importance.
Evolution of the ocean crust: results from recent seismic experiments
Authors: Orcutt J. A. , Burnett M. , McClain J. S. 
Published: April 2008

Summary
We present results from recent analyses of seismic refraction and sea-floor microseismicity studies in the Pacific and Atlantic oceans which lend support to the hypothesis that processes responsible for the construction of ophiolite suites are similar to phenomena extant at mid-ocean ridges. Seismicity at fast-spreading ridges is characterized by very low magnitude (0–1) and shallow (<2–3 km) microearthquakes and long-term oscillations or harmonic tremor. A detailed seismic-refraction experiment on a fast-spreading portion of the East Pacific Rise supports the hypothesis of the existence of a crustal magma chamber. Analyses of these data indicate that the chamber is largely unperturbed by the presence of conjugate spreading centres and the inverted delta-shaped zone of partial melt is characterized by a half width in excess of 6 km. Finally, a new approach for obtaining upper-crustal velocities when applied to data characterized by the presence of shear waves provides several counter-examples to the hypothesis that the shallow crust evolves with time.