Estimation of uncertainties in fault lateral positioning on 3D PSDM seismic image: an example from the North West Shelf

2016 ◽  
Vol 56 (2) ◽  
pp. 556
Author(s):  
Sergey Birdus ◽  
Vincent Ganivet ◽  
Alexey Artemov ◽  
Ray Teakle ◽  
Paul Phythian
Keyword(s):  
Practical Interest ◽  
Velocity Model ◽  
Lateral Position ◽  
Second Step ◽  
North West ◽  
The North ◽  
Seismic Image ◽  
Estimation Of Uncertainties ◽  
The Impact ◽  
Lateral Positioning

This extended abstract presents a two-step sequence to estimate uncertainties in lateral positioning of fault planes on 3D PSDM (pre-stack depth migration) seismic images. This analysis can be applied to any localised detail on a seismic image but, in the majority of geological settings, it is most important for the faults. The first step provides an approximate evaluation of what causes the uncertainties, how the uncertainties are distributed in a 3D space, and what to expect within target zones. The authors assume that every complex detail within a 3D PSDM velocity model causes some uncertainties to the seismic image below. Thus, the uncertainties at a target level depend on the complexity of the overburden and the seismic acquisition parameters. At this step a qualitative 3D volume of lateral fault position uncertainties is created. In the second step the authors focus on a single fault of practical interest. Based on the results of the first step, the authors modify the existing 3D PSDM anisotropic velocity model by introducing additional anomalies that cause maximal changes to the lateral position of the fault on seismic image. Then the authors iteratively re-migrate a small sub-volume around the fault and check the PSDM images and residual moveout. The objective is to find out how far the velocity variations can move the image of the fault and still satisfy available seismic data. The second step gives more reliable quantitative estimations of the impact of velocity on fault positioning. A real multi-azimuth 3D seismic dataset from the North West Shelf is used to illustrate this sequence.

Maximising the Value of Multi-Sensor Streamer Data via MAZ Processing

2021 ◽  
Author(s):  
Hui Zhang ◽  
Jianfeng Yao ◽  
Xiang Li ◽  
Kai Zhao
Keyword(s):  
Model Building ◽  
Signal To Noise Ratio ◽  
Velocity Model ◽  
Seismic Survey ◽  
High Definition ◽  
North West ◽  
The North ◽  
Dual Sensor ◽  
The Impact ◽  
Water Bottom

Abstract The North West Shelf of Australia contains a late Paleozoic to Cenozoic sedimentary succession, which attains a thickness of over 10 km and is dominated by Triassic to Lower Cretaceous sediments. The deeper plays exist at multiple stratigraphic levels including oil-prone Jurassic sediments and faulted gas-prone Triassic sediments. The area has been proven difficult as far as seismic imaging is concerned, particularly over the Madeline trend. The presence of a hard, rugose water bottom, strong reflectors beneath the water bottom, and shallow Tertiary carbonates make the Dampier Sub-basin vulnerable to multiple contamination, amplitude distortion, lower signal-to-noise ratio (S/N) and unreliable AVO response. Poor seismic quality in the data has been a significant barrier to reducing exploration risk. In the 1990s, East Dampier (1992, blue polygon in Figure 1) and Keast (1997, yellow polygon in Figure 1) seismic data were acquired in East-West and North-South directions respectively, in an effort to better understand the impact from the shallow complex overburden. To address these challenges, the Demeter survey was acquired in 2003 (black polygon in Figure 1) with a denser acquisition grid. The overall seismic quality was improved, but the results still contained a significant level of residual multiples. Later, the Fortuna survey, the most comprehensive multi-sensor seismic survey on the North West Shelf of Australia to date, was acquired in 2014 with the aim to provide better subsurface imaging (pink polygon in Figure 1) from different acquisition perspectives. The data was processed with advanced processing technology, including shallow water demultiple, deghosting and high definition tilted orthorhombic velocity model building (Birdus et al., 2017). However, the final results were still suffering from a number of challenges, specifically: 1) strong residual multiple in near offsets, 2) low S/N ratio, particularly at reservoir level, and 3) inconsistency from near to far stack resulting in unreliable AVO. In this paper, the Dixon area (green polygon), considered as the most challenging area in the Dampier Sub-basin, was chosen as the testing area for our work. By integrating high-end imaging technology, for example dual-sensor deghosting, multi-survey surface related multiple elimination (MAZ-SRME), and multi-azimuth processing (MAZ stack), we will illustrate how we have overcome many of these imaging challenges.

scholarly journals Effect of tropical cyclones on the Stratosphere-Troposphere Exchange observed using satellite observations over north Indian Ocean

2016 ◽  
Author(s):  
M. Venkat Ratnam ◽  
S. Ravindra Babu ◽  
S. S. Das ◽  
Ghouse Basha ◽  
B. V. Krishnamurthy ◽  
...  
Keyword(s):  
Water Vapor ◽  
Indian Ocean ◽  
Tropical Cyclones ◽  
Lower Stratosphere ◽  
North Indian Ocean ◽  
Satellite Observations ◽  
Upper Troposphere ◽  
North West ◽  
The North ◽  
The Impact

Abstract. Tropical cyclones play an important role in modifying the tropopause structure and dynamics as well as stratosphere-troposphere exchange (STE) process in the Upper Troposphere and Lower Stratosphere (UTLS) region. In the present study, the impact of cyclones that occurred over the North Indian Ocean during 2007–2013 on the STE process is quantified using satellite observations. Tropopause characteristics during cyclones are obtained from the Global Positioning System (GPS) Radio Occultation (RO) measurements and ozone and water vapor concentrations in UTLS region are obtained from Aura-Microwave Limb Sounder (MLS) satellite observations. The effect of cyclones on the tropopause parameters is observed to be more prominent within 500 km from the centre of cyclone. In our earlier study we have observed decrease (increase) in the tropopause altitude (temperature) up to 0.6 km (3 K) and the convective outflow level increased up to 2 km. This change leads to a total increase in the tropical tropopause layer (TTL) thickness of 3 km within the 500 km from the centre of cyclone. Interestingly, an enhancement in the ozone mixing ratio in the upper troposphere is clearly noticed within 500 km from cyclone centre whereas the enhancement in the water vapor in the lower stratosphere is more significant on south-east side extending from 500–1000 km away from the cyclone centre. We estimated the cross-tropopause mass flux for different intensities of cyclones and found that the mean flux from stratosphere to troposphere for cyclonic stroms is 0.05 ± 0.29 × 10−3 kg m−2 and for very severe cyclonic stroms it is 0.5 ± 1.07 × 10−3 kg m−2. More downward flux is noticed in the north-west and south-west side of the cyclone centre. These results indicate that the cyclones have significant impact in effecting the tropopause structure, ozone and water vapour budget and consequentially the STE in the UTLS region.

scholarly journals 'Greenfields' and 'Brownfields': automotive industrial development in the UK and in Portugal

Finisterra ◽  
2012 ◽  
Vol 31 (62) ◽  
Author(s):  
Andrew Pike ◽  
Mário Vale
Keyword(s):  
Industrial Policy ◽  
Automobile Industry ◽  
Industrial Development ◽  
Development Strategies ◽  
North West ◽  
Demonstration Effect ◽  
North East ◽  
The North ◽  
The Uk ◽  
The Impact

The industrial policy in the UK and in Portugal, as in most EU countries, seeks to attract new investment capacity, to create jobs and to promote the impact of the so-called "demonstration efect" of "greenfield" development strategies pursued in the new plants of inward investors on existing or "brownfield" plants. This industrial policy focus is particularly evident in the automobile industry.This paper compares the industrial policy oriented towards the automobile industry in the UK and in Portugal. Two recent "greenfield" investments are analised: Nissan in the North-East region (UK) and Ford/VW in the Setúbal Peninsula (Portugal), as well as three "brownfield" plants: Ford Halewood and GM Vauxhall Ellesmere Port in the North-West region (UK) and Renault in Setúbal (Portugal). The first part starts with a discussion of industrial policy in the automobile sector, the role of "greenfield" development strategies and the "demonstration effect" on "brownfield" plants. Then, the limits of new inward investment are pointed out, basically their problems and restrictions. Afterwards, the structural barriers to the "demonstration effect" within "brownfield" plants are outlined and some possabilities for alternative "brownfield" development strategies are presented.

Pashtun and Punjabi Taliban

Pakistan ◽  
2020 ◽  
pp. 131-144
Author(s):  
Mariam Abou Zahab
Keyword(s):  
North West ◽  
Competition And Cooperation ◽  
Sectarian Violence ◽  
The North ◽  
North West Frontier Province ◽  
Tribal Areas ◽  
The Impact

This chapter attempts to analyse the dynamics of the Pashtun–Punjabi nexus and the areas of competition and cooperation between Sunni sectarian groups and the Pakistani Taliban. It outlines the links between Sunni sectarian groups and the Afghan Taliban, the impact of the collapse of the Taliban regime in Afghanistan and the implications of the relocation of Punjabi jihadi/sectarian groups in the North West Frontier Province (NWFP) and the Federally Administered Tribal Areas (FATA). It also focuses on the consequences of the storming of Islamabad's Lal Masjid in July 2007, and it investigates the re-emergence of sectarian groups in Karachi and in the Punjab and its implications for Pakistan. The Punjab and Karachi have been the primary hubs of sectarian violence in Pakistan since the 1980s, but in the post-9/11 environment the Sunni-Shia conflict has assumed a new dimension.

scholarly journals Impacts of some meteorological parameters on the SO2 concentrations in the city of Obrenovac, Serbia

2010 ◽  
Vol 75 (5) ◽  
pp. 703-715 ◽  
Author(s):  
Snezana Nenadovic ◽  
Ljiljana Matovic ◽  
Misko Milanovic ◽  
Sava Janicevic ◽  
Jasmina Grbovic-Novakovic ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Power Plants ◽  
Meteorological Parameters ◽  
North West ◽  
Wind Speeds ◽  
The North ◽  
West Part ◽  
Measuring Site ◽  
The Impact ◽  
The City

In this paper, the impacts of some meteorological parameters on the SO2 concentrations in the City of Obrenovac are presented. The City of Obrenovac is located in the north-west part of Serbia on the banks of the River Sava. The observed source emission, the power plants TENT A and TENT B are situated on the bank of the Sava River in the vicinity of Obrenovac. During the period from January to November 2006, the concentrations of sulfur dioxide in the air at 4 monitoring sites in Obrenovac were measured. It was noticed that the maximal measured daily concentrations of sulfur dioxide ranged from 1 ?g/m3 (16th November, 2006) to 98 ?g/m3 (29th January 2006) and lie under the maximal allowed concentration value according to the Serbian Law on Environmental Protection. The measured sulfur dioxide concentrations mostly showed characteristics usual for a daily acidification sulfur dioxide cycle, excluding the specificities influenced by the measuring site itself. Sulfur dioxide transport was recorded at increased wind speeds, primarily from the southeast direction. Based on the impact of meteorological parameters on the sulfur dioxide concentration, a validation of the monitoring sites was also performed from the aspect of their representivity.

scholarly journals The impact of sea-level rise on tidal characteristics around Australia

Ocean Science ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 147-159 ◽  
Author(s):  
Alexander Harker ◽  
J. A. Mattias Green ◽  
Michael Schindelegger ◽  
Sophie-Berenice Wilmes
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Tidal Dissipation ◽  
North West ◽  
The North ◽  
Tidal Changes ◽  
Tidal Characteristics ◽  
The Impact

Abstract. An established tidal model, validated for present-day conditions, is used to investigate the effect of large levels of sea-level rise (SLR) on tidal characteristics around Australasia. SLR is implemented through a uniform depth increase across the model domain, with a comparison between the implementation of coastal defences or allowing low-lying land to flood. The complex spatial response of the semi-diurnal M2 constituent does not appear to be linear with the imposed SLR. The most predominant features of this response are the generation of new amphidromic systems within the Gulf of Carpentaria and large-amplitude changes in the Arafura Sea, to the north of Australia, and within embayments along Australia's north-west coast. Dissipation from M2 notably decreases along north-west Australia but is enhanced around New Zealand and the island chains to the north. The diurnal constituent, K1, is found to decrease in amplitude in the Gulf of Carpentaria when flooding is allowed. Coastal flooding has a profound impact on the response of tidal amplitudes to SLR by creating local regions of increased tidal dissipation and altering the coastal topography. Our results also highlight the necessity for regional models to use correct open boundary conditions reflecting the global tidal changes in response to SLR.

Bodies in the field: methodological reflections on Tai Chi and pregnancy in an ethnographic study at a Chinese community centre in the North West of England

2020 ◽  
pp. 146879412091881
Author(s):  
Naomi Wood
Keyword(s):  
Tai Chi ◽  
Ethnographic Study ◽  
The Body ◽  
Chinese Community ◽  
Verbal Interactions ◽  
North West ◽  
Research Participants ◽  
The North ◽  
The Impact ◽  
Community Centre

This article explores the idea of the body as a research tool in ethnographic fieldwork, looking specifically at how the body can play a part in facilitating and developing relationships in the field. I use my experiences of fieldwork, undertaken in a Chinese community centre in the North West of England, to explore this in two ways. Firstly, through the process of using the body to learn a physical skill – Tai Chi – alongside the other centre members; and secondly through my pregnancy in the field, in order to consider what is communicated and enabled through the particular nature of specific bodies in the field. Both examples explore fieldwork as embodied, relational and intersubjective; in both, relationships with research participants are forged and developed in different ways through the body. Implications are drawn from this in relation to the impact of the research participants on the researcher and in relation to aspects of building relationships in the field that do not rely solely on verbal interactions or shared language, particularly in multi-cultural and multi-lingual research sites.

scholarly journals Detection of Virulence Genes in Multidrug Resistant Enterococci Isolated from Feedlots Dairy and Beef Cattle: Implications for Human Health and Food Safety

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Frank Eric Tatsing Foka ◽  
Collins Njie Ateba
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Efflux Pump ◽  
Health Sector ◽  
Multidrug Resistant ◽  
North West ◽  
The North ◽  
Vancomycin Resistant ◽  
The Impact

The misuse/abuse of antibiotics in intensive animal rearing and communities led to the emergence of resistant isolates such as vancomycin-resistant enterococci (VREs) worldwide. This has become a major source of concern for the public health sector. The aim of this study was to report the antibiotic resistance profiles and to highlight the presence of virulence genes in VREs isolated from feedlots cattle of the North-West Province of South Africa. 384 faecal samples, 24 drinking troughs water, and 24 soil samples were collected aseptically from 6 registered feedlots. Biochemical and molecular methods were used to identify and categorise the enterococci isolates. Their antibiotic resistance profiles were assessed and genotypic methods were used to determine their antibiotic resistance and their virulence profiles. 527 presumptive isolates were recovered, out of which 289 isolates were confirmed asEnterococcussp. Specifically,E. faecalis(9%),E. faecium(10%),E. durans(69%),E. gallinarum(6%),E. casseliflavus(2%),E. mundtii(2%), andE. avium(2%) were screened after molecular assays.VanA(62%),vanB(17%), andvanC(21%) resistance genes were detected in 176Enterococcussp., respectively. Moreover,tetK(26),tetL(57),msrA/B(111), andmefA(9) efflux pump genes were detected in 138 VRE isolates.Multiple antibiotic resistances were confirmed in all the VRE isolates of this study; the most common antibiotic resistance phenotype wasTETR-AMPR-AMXR-VANR-PENR-LINR-ERYR.CylA,hyl,esp,gelE, andasa1virulence genes were detected in 86 VREs with the exception of vancomycin-resistantE. mundtiiisolates that did not display any virulence factor. Most VRE isolates had more than one virulence genes but the most encountered virulence profile wasgelE-hyl. Potentially pathogenic multidrug resistant VREs were detected in this study; this highlights the impact of extensive usage of antimicrobials in intensive animal rearing and its implications on public health cannot be undermined.

scholarly journals The institution and the city: the impact of hospitals and workhouses on the development of Dublin's north inner city, c. 1773–1911

Urban History ◽  
2019 ◽  
Vol 47 (4) ◽  
pp. 671-688
Author(s):  
Katherine Fennelly
Keyword(s):  
Inner City ◽  
Urban Areas ◽  
Industrial Development ◽  
Social Identities ◽  
North West ◽  
The North ◽  
The Social ◽  
Industry And Commerce ◽  
The Impact ◽  
The City

AbstractCities develop around industry, markets and transport links. Dublin in the nineteenth century was similar, but additionally the north-west of the city developed around the expansion of a complex of institutional buildings for the reception, confinement and welfare of the poor and sick. This article argues that these institutions were implicit in the development of the modern city in the same way as industry and commerce. The physical development of the buildings altered and defined both the streetscape and, over time, the social identities and historical communities in the locale, in the same way that industrial development defined urban areas.

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