Cenozoic salt tectonics in the Officer Basin, Western Australia: implications for hydrocarbon exploration

2014 ◽  
Vol 54 (1) ◽  
pp. 167
Author(s):  
Jane Cunneen ◽  
Warwick Crowe ◽  
Geoff Peters
Keyword(s):  
Seismic Data ◽  
Gravity Data ◽  
Cost Effective ◽  
Shuttle Radar Topography Mission ◽  
Hydrocarbon Exploration ◽  
The West ◽  
Potential Field Data ◽  
Hydrocarbon Traps ◽  
Exploration Tool ◽  
Migration Pathways

The Neoproterozoic western Officer Basin has a total sedimentary fill of up to 8 km and a depositional history with similarities to other central Australian basins, particularly the Amadeus Basin. The size and remoteness of the basin has traditionally been an impediment to exploration, and only sparse seismic and well data are available. In such areas, potential field data can be a powerful exploration tool to assess petroleum prospectively. Salt distribution and mobilisation in the Officer Basin is poorly understood and has been significantly under-estimated due to a lack of quality seismic data. Examination of the existing aeromagnetic, gravity and seismic data, along with satellite and Shuttle Radar Topography Mission (SRTM) data, indicate that surface and shallow salt is abundant in the northern and central parts of the basin. Remobilisation of salt is greatest in the eastern part of the study area, decreasing towards the west, although the extent of salt occurrence to the west is unclear. Salt diapirs occur along structural trends; east to west in the northeastern (Gibson) part of the basin, and northwest to southeast in the central (Yowalga) area. Neotectonic features such as surface lineaments and recent earthquake data suggest that minor tectonic reactivation is occurring in the present day, and is consistent with a present-day stress orientation of approximately 095°. Miocene to recent stress orientations suggest that structures in the Gibson area may have been reactivated as right lateral faults, whereas those in the Yowalga area are reactivated as left lateral faults. Potential trap styles in the western Officer Basin include structural plays related to salt movement, such as drape folds, diaper overhangs, and thrusts. Late-stage movement of salt must, therefore, be considered when assessing the timing of migration pathways and possible seal breach. An improved understanding of the extent of salt in the Officer Basin, and the degree of reactivation during the Cenozoic, is vital for successful exploration in the region. Acquisition of high-resolution magnetic and gravity data would be a cost-effective exploration tool for better definition of salt and associated hydrocarbon traps.

Cannibalization and sealing of deepwater reservoirs by mass-transport complexes — The Jubilee field, Gulf of Mexico

2020 ◽  
Vol 8 (4) ◽  
pp. SV17-SV30
Author(s):  
Sebastian Cardona ◽  
Lesli Wood ◽  
Lorena Moscardelli ◽  
Dallas Dunlap
Keyword(s):  
Gulf Of Mexico ◽  
Mass Transport ◽  
Seismic Data ◽  
Hydrocarbon Exploration ◽  
Fluid Migration ◽  
Gas Field ◽  
Mass Flows ◽  
Gas Chimneys ◽  
Migration Pathways ◽  
Reservoir Deposits

Mass-transport complexes (MTCs) are important stratigraphic elements in many deepwater basins. In hydrocarbon exploration, MTCs have traditionally been identified as seals although they can also act as migration pathways or cannibalize and compartmentalize adjacent reservoirs. Although the ever-improving resolution of seismic data has enhanced the knowledge about these deposits (e.g., geometry, distribution), at present the potential of MTCs to act as top and/or lateral seals is difficult to predict predrilling and few case studies are publicly available. The key objective here is to present examples of seismically resolvable characteristics of two MTCs in the Jubilee gas field, offshore Gulf of Mexico: one of the MTCs cannibalized part of the reservoir, and the other acted as the top seal. The Jubilee field is an area where the ability of MTCs to act as a top seal has been proven — the field produced approximately 205 billion cubic feet of natural gas until abandonment in 2016. When evaluating the sealing potential of MTCs, seismic interpretation can offer a powerful technique to identify indicators of hydrocarbon leakage. Additionally, mass flows that form MTCs can be highly erosive and cannibalize underlying reservoir deposits, which increase reservoir heterogeneity that can lead to compartmentalization. Our results indicate that the seal MTC in the Jubilee field is a detached MTC and that the translational morphodomain overlies the gas accumulation. Consequently, when predicting the seal potential of MTCs from seismic data, it is important to determine (1) the type of MTC (i.e., attached versus detached), (2) the specific MTC morphodomain overlying the hydrocarbon accumulation/prospect (i.e., the headwall, translational, or toe morphodomains), and (3) the presence of seismic indicators of fluid migration pathways (e.g., gas chimneys, pockmarks, etc.). These results shed some light on the present challenges of predicting the seal potential of MTCs in frontier basins around the world.

Relationship between salt and crustal tectonics in the Sørvestsnaget Basin, SW Barents Sea

2020 ◽  
Author(s):  
Gaia Travan ◽  
Benjamin Bellwald ◽  
Sverre Planke ◽  
Virginie Gaullier ◽  
Dwarika Maharjan ◽  
...  
Keyword(s):  
Seismic Data ◽  
Potential Field ◽  
Field Data ◽  
Barents Sea ◽  
Hydrocarbon Exploration ◽  
Salt Tectonics ◽  
Potential Field Data ◽  
The Barents Sea ◽  
Western Side ◽  
Seismic Anomalies

<p>The geology of the Barents Sea has been widely studied because of the interest for hydrocarbon exploration. Our study focuses on the SW Barents Sea, on the western side of the Senja Ridge in the Sørvestsnagets Basin, which is still a less deciphered area. Located at the limit of the continental shelf, this deep Cretaceous basin is characterized by a several-kilometer-thick sequence of Cenozoic sediments locally influenced by salt structures. Because of the peculiar rheological characteristics of salt, the deposition of evaporites during Permo-Carboniferous times still represents a key aspect to deeply understand the geological setting because salt tectonics considerably affects the brittle sedimentary cover.</p><p>5,500 km<sup>2</sup> of high-quality 3D seismic data, integrated with potential field data and existing wells, led to the interpretation of the main horizons and unconformities in the sedimentary sequence, with focus on the salt structures.</p><p>The top of the salt is characterized by a strong positive-amplitude reflection in the seismic data, and has been interpreted with a line spacing of 100 m. Subsequent gridding of the interpreted horizon to a bin size of 12.5 m highlights that the geomorphology for the top of the three salt structures is particularly complex, with presence of salt horns and development of minibasins above the salt. Integration of potential field data shows a strong correlation between salt structures and low values in Bouguer-Gravity anomalies. Different families of faults related to salt and to crustal tectonics have been mapped, and strong seismic anomalies related to faults above the salt structures are identified at multiple stratigraphic levels. Part of these faults have been active until 20 000 years ago, and are rarely active at present day.</p><p>The three salt structures interpreted on the western side of the Senja Ridge have a total extent of around 800 km<sup>2</sup> and are mainly the consequence of different pulses of reactive diapirism, due to several diachronous rifting events during the opening of the Barents Sea. After the opening of the Sørvestsnagets Basin, salt tectonics continued and was influenced by crustal movements and glacial sedimentation and erosion in this pull-apart basin setting.</p><p>The presence of the strong seismic anomalies above the salt structures is interpreted as gas accumulations, which makes this topic of particular interest for the future development of the oil and gas industry of the SW Barents Sea.</p>

scholarly journals Combined Gravimetric-Seismic Moho Model of Tibet

Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 461 ◽  
Author(s):  
Alexey Baranov ◽  
Mohammad Bagherbandi ◽  
Robert Tenzer
Keyword(s):  
Ocean Circulation ◽  
Seismic Data ◽  
Deep Structure ◽  
Gravity Data ◽  
Satellite Observation ◽  
Shuttle Radar Topography Mission ◽  
Moho Depth ◽  
The Tibetan Plateau ◽  
Local Maxima ◽  
Topographic Data

Substantial progress has been achieved over the last four decades to better understand a deep structure in the Himalayas and Tibet. Nevertheless, the remoteness of this part of the world still considerably limits the use of seismic data. A possible way to overcome this practical restriction partially is to use products from the Earth’s satellite observation systems. Global topographic data are provided by the Shuttle Radar Topography Mission (SRTM). Global gravitational models have been derived from observables delivered by the gravity-dedicated satellite missions, such as the Gravity Recovery and Climate Experiment (GRACE) and the Gravity field and steady-state Ocean Circulation Explorer (GOCE). Optimally, the topographic and gravity data should be combined with available results from tomographic surveys to interpret the lithospheric structure, including also a Moho relief. In this study, we use seismic, gravity, and topographic data to estimate the Moho depth under orogenic structures of the Himalayas and Tibet. The combined Moho model is computed based on solving the Vening Meinesz–Moritz (VMM) inverse problem of isostasy, while incorporating seismic data to constrain the gravimetric solution. The result of the combined gravimetric-seismic data analysis exhibits an anticipated more detailed structure of the Moho geometry when compared to the solution obtained merely from seismic data. This is especially evident over regions with sparse seismic data coverage. The newly-determined combined Moho model of Tibet shows a typical contrast between a thick crustal structure of orogenic formations compared to a thinner crust of continental basins. The Moho depth under most of the Himalayas and the Tibetan Plateau is typically within 60–70 km. The maximum Moho deepening of ~76 km occurs to the south of the Bangong-Nujiang suture under the Lhasa terrane. Local maxima of the Moho depth to ~74 km are also found beneath Taksha at the Karakoram fault. This Moho pattern generally agrees with the findings from existing gravimetric and seismic studies, but some inconsistencies are also identified and discussed in this study.

scholarly journals Biostratigraphy of the Lower Palaeozoic Haima Supergroup, Oman; its application in sequence stratigraphy and hydrocarbon exploration

GeoArabia ◽  
2006 ◽  
Vol 11 (2) ◽  
pp. 17-48 ◽  
Author(s):  
Stewart Molyneux ◽  
Peter Osterloff ◽  
Randall Penney ◽  
Pieter Spaak
Keyword(s):  
Sequence Stratigraphy ◽  
Cost Effective ◽  
Hydrocarbon Exploration ◽  
Exploration And Exploitation ◽  
The West ◽  
Flooding Event ◽  
Key Species ◽  
Low Diversity ◽  
Lower Palaeozoic ◽  
Flooding Events

ABSTRACT The siliciclastic Haima Supergroup (Cambrian-Silurian) on the west flank of Al Ghabah Salt Basin in Oman is currently a target for gas exploration following the discovery of significant gas reserves. An understanding of stratigraphical and facies relationships within the Haima is crucial for their exploration and exploitation, and biostratigraphy is one of the more powerful and cost-effective tools that can be deployed to aid such understanding. The biostratigraphy of the Haima Supergroup is based primarily on palynomorphs. The pre-existing biozonation, comprising conventional interval zones, is of low resolution and incorporates misconceptions over the ranges of key species. The work reported here explicitly considered the biostratigraphy of the Haima Supergroup in the context of genetic sequence stratigraphy. It shows that each of the postulated marine-flooding events in the Haima Supergroup is characterised by a unique assemblage of marine palynomorphs. Intervening strata are characterised by low-diversity and sometimes sparse marine palynomorph assemblages, often comprising only sphaeromorph acritarchs, accompanied by terrestrial cryptospores. These low-diversity assemblages indicate proximal-marine to non-marine conditions, consistent with progradation following each marine flood. The sandy prograding deposits in the Haima Supergroup form reservoirs, which are sealed by the shales and mudstones deposited by succeeding marine-flooding events. Lateral changes in marine assemblages indicate onshore-offshore relationships, and have contributed towards mapping the extent of each marine-flooding event, critical for evaluation of the potential areal extent of seals. The result is improved biostratigraphical resolution, which enables more precise correlation between wells, and which has contributed to more detailed palaeogeographical maps and to a better assessment of the distribution of reservoir-seal pairs.

scholarly journals Petroleum systems and structures offshore central West Greenland: implications for hydrocarbon prospectivity

2007 ◽  
Vol 13 ◽  
pp. 25-28 ◽  
Author(s):  
Ulrik Gregersen ◽  
Torben Bidstrup ◽  
Jørgen A. Bojesen-Koefoed ◽  
Flemming G. Christiansen ◽  
Finn Dalhoff ◽  
...  
Keyword(s):  
Seismic Data ◽  
Gravity Data ◽  
Hydrocarbon Exploration ◽  
Source Rocks ◽  
Structural Development ◽  
Structural Elements ◽  
West Greenland ◽  
Petroleum Systems ◽  
Major Interest ◽  
Offshore Region

A detailed geophysical mapping project has been carried out by the Geological Survey of Denmark and Greenland (GEUS) in the offshore region south-west and west of Disko and Nuussuaq, central West Greenland as part of the preparations for the Disko West Licensing Round in 2006 (Fig. 1). The main purpose of the study was to evaluate the prospectivity of this almost 100 000 km2 large region, and to increase knowledge of basin evolution and the structural development. Results of the work, including a new structural elements map of the region and highlights of particular interest for hydrocarbon exploration of this area, are summarised below. Evidence of live petroleum systems has been recognised in the onshore areas since the beginning of the 1990s when seeps of five different oil types were demonstrated (BojesenKoefoed et al. 1999). Oil seeps suggesting widely distributed marine source rocks of Mesozoic age are particularly promising for the exploration potential (Bojesen-Koefoed et al. 2004, 2007). Furthermore, possible DHIs (Direct Hydro carbon Indicators) such as gas-clouds, pock marks, bright spots and flat events have been interpreted in the offshore region (Skaarup et al. 2000; Gregersen & Bidstrup in press). The evaluation of the region (Fig. 1) is based on all public and proprietary seismic data together with public domainmag- netic and gravity data. The seismic data (a total of c. 28 000 line km) are tied to the two existing offshore exploration wells in the region (Hellefisk-1 and Ikermiut-1). The study also incorporates information on sediments and volcanic rocks from onshore Disko and Nuussuaq (Fig. 2). Ten seismic horizons ranging from ‘mid-Cretaceous’ to ‘Base Quaternary’ (Fig. 2) have been interpreted regionally. Large correlation distances to wells, varying data quality and a thick cover of basalt in the north-eastern part of the region, add uncertainty in the regional interpretation, especially for the deeper horizons such as the ‘mid-Cretaceous’ equivalent to Santonian sandstone interval drilled in Qulleq-1 far south. Based on the seismic interpretation (Fig. 3) structural elements maps, horizon-depth maps and isopach maps have been produced; these maps, together with general stratigraphic knowledge on potential reservoirs, seals and source rocks (Fig. 2), provide important information for discussions of critical play elements including kitchens and structures.The existence of many large structures combined with the evidence of live petroleum systems has spurred the recent major interest for hydrocarbon exploration in the region.

scholarly journals Comparing global tomography-derived and gravity-based upper mantle density models

2020 ◽  
Vol 221 (3) ◽  
pp. 1542-1554 ◽  
Author(s):  
B C Root
Keyword(s):  
Seismic Tomography ◽  
Upper Mantle ◽  
Seismic Data ◽  
Gravity Data ◽  
Heterogeneous Data ◽  
Clear Correlation ◽  
Data Sets ◽  
Satellite Gravity ◽  
Similar Density ◽  
Similar Peak

SUMMARY Current seismic tomography models show a complex environment underneath the crust, corroborated by high-precision satellite gravity observations. Both data sets are used to independently explore the density structure of the upper mantle. However, combining these two data sets proves to be challenging. The gravity-data has an inherent insensitivity in the radial direction and seismic tomography has a heterogeneous data acquisition, resulting in smoothed tomography models with de-correlation between different models for the mid-to-small wavelength features. Therefore, this study aims to assess and quantify the effect of regularization on a seismic tomography model by exploiting the high lateral sensitivity of gravity data. Seismic tomography models, SL2013sv, SAVANI, SMEAN2 and S40RTS are compared to a gravity-based density model of the upper mantle. In order to obtain similar density solutions compared to the seismic-derived models, the gravity-based model needs to be smoothed with a Gaussian filter. Different smoothening characteristics are observed for the variety of seismic tomography models, relating to the regularization approach in the inversions. Various S40RTS models with similar seismic data but different regularization settings show that the smoothening effect is stronger with increasing regularization. The type of regularization has a dominant effect on the final tomography solution. To reduce the effect of regularization on the tomography models, an enhancement procedure is proposed. This enhancement should be performed within the spectral domain of the actual resolution of the seismic tomography model. The enhanced seismic tomography models show improved spatial correlation with each other and with the gravity-based model. The variation of the density anomalies have similar peak-to-peak magnitudes and clear correlation to geological structures. The resolvement of the spectral misalignment between tomographic models and gravity-based solutions is the first step in the improvement of multidata inversion studies of the upper mantle and benefit from the advantages in both data sets.

Computer Application in Geosciences: Imaging of the Subsurface by Structural Coupled Inversion of Potential Field Data

2014 ◽  
Vol 644-650 ◽  
pp. 2670-2673
Author(s):  
Jun Wang ◽  
Xiao Hong Meng ◽  
Fang Li ◽  
Jun Jie Zhou
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Gravity Data ◽  
Computer Application ◽  
Magnetic Data ◽  
Imaging Method ◽  
Inversion Algorithm ◽  
Constant Property ◽  
Near Surface ◽  
Potential Field Data

With the continuing growth in influence of near surface geophysics, the research of the subsurface structure is of great significance. Geophysical imaging is one of the efficient computer tools that can be applied. This paper utilize the inversion of potential field data to do the subsurface imaging. Here, gravity data and magnetic data are inverted together with structural coupled inversion algorithm. The subspace (model space) is divided into a set of rectangular cells by an orthogonal 2D mesh and assume a constant property (density and magnetic susceptibility) value within each cell. The inversion matrix equation is solved as an unconstrained optimization problem with conjugate gradient method (CG). This imaging method is applied to synthetic data for typical models of gravity and magnetic anomalies and is tested on field data.

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