AUSTRALIAN MEGASURVEYS—THE KEY TO NEW DISCOVERIES IN MATURING AREAS?

2005 ◽  
Vol 45 (1) ◽  
pp. 407 ◽  
Author(s):  
H. Edwards ◽  
J. Crosby ◽  
N. David ◽  
C. Loader ◽  
S. Westlake
Keyword(s):  
Data Sets ◽  
Well Control ◽  
North West ◽  
Oil Companies ◽  
The North ◽  
3D Data ◽  
Detailed Search ◽  
Time Critical ◽  
Small Finds ◽  
2D And 3D

In a maturing province such as the North West Shelf, it is time-critical to find remaining hydrocarbon resources as well as to develop small finds before existing big field installations and their associated infrastructure are decommissioned. Finding the remaining smaller fields with subtle geophysical expression is a challenge, and a thorough understanding of the petroleum geology is essential. To achieve this, the subsurface structure and depositional systems must be understood in a regional as well as a local context.To date, exploration companies’ regional models have been based on a mixture of 2D and 3D seismic of varying vintages, orientations, and quality. Consequently they have been incomplete and lacking detail. To address this problem, PGS initiated the MegaSurvey Project, merging a number of 3D surveys into large, consistent 3D data sets. For the first time, the regional picture and prospect-size detail are both available from a single dataset.Two MegaSurveys for the North West Shelf are now available; the Vulcan Sub-Basin MegaSurvey (VMS) and the Carnarvon MegaSurvey (CMS).The MegaSurvey seismic data and consistent horizon interpretation (tied to released well control) enables asset- focussed oil companies to concentrate on the more detailed search-for-the-subtle-trap to find, understand, and develop remaining reserves. Interpretation of the first MegaSurvey (Vulcan Sub-Basin) was completed in 2004 and work is focussed on the Carnarvon MegaSurvey, the interpretation of which will be completed in March 2005.The PGS 3D MegaSurveys allow visualisation of the subsurface both on a scale and resolution that has hitherto been unavailable. They provide an essential new tool to help fully unlock the remaining potential of the North West Shelf.

Prospectivity insights from automated pre-interpretation processing of open-file 3D seismic data: characterising the Late Triassic Mungaroo Formation of the Carnarvon Basin, North West Shelf of Australia

2015 ◽  
Vol 55 (1) ◽  
pp. 15 ◽  
Author(s):  
Cliff C. Ford ◽  
James K. Dirstein ◽  
Alistair John Stanley
Keyword(s):  
Spatial Databases ◽  
Late Triassic ◽  
Data Sets ◽  
3D Seismic ◽  
Gas Reservoirs ◽  
Waveform Data ◽  
Open File ◽  
North West ◽  
The North ◽  
Carnarvon Basin

Waveform data from pre-interpretation processing is used in nine Late Triassic interpretation case studies from an area extending more than 30,000 km2 across the Exmouth Plateau, Kangaroo Trough and Rankin Trend on the North West Shelf of Australia. Events selected from a database of automatically generated surfaces extracted from six large open-file 3D marine surveys (~16,000 km2) are used to analyse reservoirs, seals, and pore fluid within the Brigadier and Mungaroo formations in this peer-reviewed paper. Today, geoscience teams are challenged with vast data sets such as the archived versions of more than 125 Carnarvon Basin 3D seismic surveys. Pre-interpretation processing delivers a database of numerous seismic events that cannot be effectively managed using traditional interpretation workstations. With, however, a 3D viewer to query, edit and merge the results, geoscience teams are able to review many large surveys and the surfaces in their interpretation workflows. At the 2013 WABS Conference in Perth, WA, two papers offered models for the Late Triassic gas reservoirs. These models represent many years of synthesis and integration of data by teams of geoscientists from two of the major operators on the North West Shelf. Validation and corroboration of the proposed models was gained by using selected pre-interpretation surfaces. Stacking patterns, waveform fitness, amplitude and two-way time surfaces from these spatial databases revealed geological insights about the formations, such as their complexity of structure, extent of reservoirs, and continuity of seals, along with a better understanding about the trapping and charge systems of the fields.

IMPACT OF 3D SEISMIC ON EXPLORATION AND DRILLING SUCCESS IN THE DAMPIER SUB-BASIN, WA

1999 ◽  
Vol 39 (1) ◽  
pp. 87
Author(s):  
D.R. Kingsley ◽  
L.A. Tilbury
Keyword(s):  
Success Rate ◽  
3D Seismic ◽  
3D Technology ◽  
Spatial Continuity ◽  
North West ◽  
Associated Production ◽  
The North ◽  
3D Data ◽  
Stratigraphic Reservoir ◽  
Structural Definition

Application of 3D technology and the strategy of acquiring 'wall-to-wall' 3D data over WA-28-P and the associated production licences has had a major impact on the exploration and appraisal success of the North West Shelf Venture.The different aspects of 3D technology have contributed to this success to varying degrees according to the geological setting of the prospects and fields. In general, all have benefited from improved structural definition, better stratigraphic/reservoir definition, improved depth conversion and the spatial continuity of data inherent in 3D datasets.Noteable discoveries attributable to 3D technology include North Rankin West (NRA–22), Perseus–1 (and appraisals Perseus–2, –3A, Perseus South–1), Capella–1, Sculptor–1, Hermes (Lambert–2), Keast–1, Dockrell–2, and appraisal wells Yodel–2, Egret–2 and Lambert–4. Despite this outstanding success, several noteable dry wells, including West Dixon–1 (Triassic), Spica–1, Malmsey–1 and Wanaea–5 (appraisal), have been drilled.The continuing application of 3D technology, although in an increasingly mature area where more subtle and higher risk traps will be the norm, is expected to maintain a high success rate for the North West Shelf Venture.

scholarly journals High prevalence of SARS-CoV-2 swab positivity and increasing R number in England during October 2020: REACT-1 round 6 interim report

2020 ◽  
Author(s):  
Steven Riley ◽  
Kylie E. C. Ainslie ◽  
Oliver Eales ◽  
Caroline E. Walters ◽  
Haowei Wang ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Temporal Trends ◽  
Age Groups ◽  
North West ◽  
The North ◽  
East Midlands ◽  
High Prevalence ◽  
Previous Round ◽  
Time Critical ◽  
Estimate Prevalence

AbstractBackgroundREACT-1 measures prevalence of SARS-CoV-2 infection in representative samples of the population in England using PCR testing from self-administered nose and throat swabs. Here we report interim results for round 6 of observations for swabs collected from the 16th to 25th October 2020 inclusive.MethodsREACT-1 round 6 aims to collect data and swab results from 160,000 people aged 5 and above. Here we report results from the first 86,000 individuals. We estimate prevalence of PCR-confirmed SARS-CoV-2 infection, reproduction numbers (R) and temporal trends using exponential growth or decay models. Prevalence estimates are presented both unweighted and weighted to be representative of the population of England, accounting for response rate, region, deprivation and ethnicity. We compare these interim results with data from round 5, based on swabs collected from 18th September to 5th October 2020 inclusive.ResultsOverall prevalence of infection in the community in England was 1.28% or 128 people per 10,000, up from 60 per 10,000 in the previous round. Infections were doubling every 9.0 (6.1, 18) days with a national reproduction number (R) estimated at 1.56 (1.27, 1.88) compared to 1.16 (1.05, 1.27) in the previous round. Prevalence of infection was highest in Yorkshire and The Humber at 2.72% (2.12%, 3.50%), up from 0.84% (0.60%, 1.17%), and the North West at 2.27% (1.90%, 2.72%), up from 1.21% (1.01%, 1.46%), and lowest in South East at 0.55% (0.45%, 0.68%), up from 0.29% (0.23%, 0.37%). Clustering of cases was more prevalent in Lancashire, Manchester, Liverpool and West Yorkshire, West Midlands and East Midlands. Interim estimates of R were above 2 in the South East, East of England, London and South West, but with wide confidence intervals. Nationally, prevalence increased across all age groups with the greatest increase in those aged 55-64 at 1.20% (0.99%, 1.46%), up 3-fold from 0.37% (0.30%, 0.46%). In those aged over 65, prevalence was 0.81% (0.58%, 0.96%) up 2-fold from 0.35% (0.28%, 0.43%). Prevalence remained highest in 18 to 24-year olds at 2.25% (1.47%, 3.42%).ConclusionThe co-occurrence of high prevalence and rapid growth means that the second wave of the epidemic in England has now reached a critical stage. Whether via regional or national measures, it is now time-critical to control the virus and turn R below one if further hospital admissions and deaths from COVID-19 are to be avoided.

scholarly journals ROLE OF 2D AND 3D MODELS IN JONSDAP '76

1978 ◽  
Vol 1 (16) ◽  
pp. 63
Author(s):  
A.M. Davies
Keyword(s):  
North Sea ◽  
Three Dimensional ◽  
3D Models ◽  
Three Dimensional Model ◽  
North West ◽  
The North ◽  
Dimensional Distribution ◽  
The North Sea ◽  
2D And 3D

This paper describes how a two-dimensional numerical model of the North Sea was used to determine optimum positions for the deployment of off-shore tide gauges during the JONSDAP '76 oceanographic exercise. A three-dimensional model of the North West European Shelf is also described. Using this model the three-dimensional distribution of the M2 tidal current over the shelf has been computed. This model has also been used to compute the wind induced circulation of the North Sea for the INOUT period of JONSDAP '76.

STRUCTURING AND CONTROLS ON DEVONIAN REEF DEVELOPMENT ON THE NORTH-WEST BARBWIRE AND ADJACENT TERRACES, CANNING BASIN

1987 ◽  
Vol 27 (1) ◽  
pp. 137 ◽  
Author(s):  
John Begg
Keyword(s):  
Carbonate Platform ◽  
Late Ordovician ◽  
Surface Distribution ◽  
Well Control ◽  
North West ◽  
Canning Basin ◽  
The North ◽  
History Of Development ◽  
History Of ◽  
Northern Side

The major terraces flanking the southern margin of the Fitzroy Trough have had a complex history of development involving at least four major episodes of structuring with varying degrees of intensity from the Mid-Late Ordovician Rodingan Movement through to the Latest Triassic-Early Jurassic Fitzroy Movement. Extensive salt tectonism associated with the massive evaporite deposits of the Silurian Carribuddy Formation has also had a profound effect on structuring in these areas.Despite sparse well control, seismic recognition of the resultant structural styles has provided the basis for more comprehensive modelling of the main controls on sedimentation than has previously been possible.In particular, a complex sub-surface distribution of stacked Devonian carbonate platform and reef complexes can now be recognised, having similar morphologies to the spectacular outcrop on the northern side of the Fitzroy Trough. In addition to broad platform areas, individual peninsula developments, isolated atolls and extensive inter-reef seaways were present at both Pillara and Nullara cycle levels, largely controlled by faulting initiated in the Mid-Devonian and influenced in some cases by salt diapirism.Identification of the carbonate and associated palaeogeographic trends will provide direction for future exploration efforts in this wildcat area.

scholarly journals 3D Subsurface Modeling of Multi-Scenario Rock Property and AVO Feasibility Cubes—An Integrated Workflow

2021 ◽  
Vol 9 ◽  
Author(s):  
Per Avseth ◽  
Ivan Lehocki
Keyword(s):  
Barents Sea ◽  
Seismic Velocity ◽  
Rock Physics ◽  
Training Data ◽  
Well Control ◽  
Rock Property ◽  
The North ◽  
The North Sea ◽  
Velocity Information ◽  
2D And 3D

A novel inter-disciplinary methodology for the generation of rock property and AVO feasibility maps or cubes to be used in subsurface characterization and prospect de-risking is presented. We demonstrate the workflow for 1D, 2D and 3D cases on data from the North Sea and the Barents Sea, offshore Norway. The methodology enables rapid extrapolation of expected rock physics properties away from well control along selected horizons, constrained by seismic velocity information, geological inputs (basin modeling, seismic stratigraphy and facies maps) and rock physics depth trend analysis. In this way, the expected rock physics properties of a reservoir sandstone (saturated with any pore fluid) can be predicted at any given location between or away from existing wells while honoring rock’s burial and thermal history at this same location. The workflow should allow for more rapid, seamless and geologically consistent subsurface mapping and de-risking of prospects in areas with complex geology and tectonic influence. The AVO feasibility results can furthermore be utilized to generate non-stationary training data for AVO classification.

Application of formation pressure while drilling in Australia: North West Shelf examples

2009 ◽  
Vol 49 (2) ◽  
pp. 568
Author(s):  
Dmitry Molohkov ◽  
Andy Pietsch ◽  
Jack Harfoushian ◽  
Shahid Azizul Haq
Keyword(s):  
Drill Pipe ◽  
Cost Effective ◽  
Lessons Learned ◽  
Formation Pressure ◽  
Well Control ◽  
North West ◽  
Service Companies ◽  
The North ◽  
Essential Input ◽  
Formation Pore Pressure

Since its introduction in the 1950s, the point-by-point wireline formation pressure measurement technique has been successfully used for formation evaluation and reservoir management, and has been an essential input into reservoir models. In exploration and appraisal wells, where depletion has not yet affected the reservoir, vertical pressure profiling can be used for fluid gradient determination that may be interpreted in terms of fluid densities and contacts. In a dynamic producing environment pressure measurements can help to identify vertical and horizontal boundaries and communication. Measurement of pressure distribution along the borehole was historically done with wireline instruments or, in difficult logging conditions, with wireline instruments conveyed by drill pipe. In some environments, especially in highly deviated and S-shaped wells or unconsolidated formations, drill pipe conveyance of wireline formation pressure testers introduces significant operational risk. Formation Pressure While Drilling (FPWD), introduced in 2003, offers a new cost-effective solution for gathering formation pressure data. FPWD is a new method to directly measure formation pore pressure as the well is being drilled, extending its application beyond traditional fluid typing, contacts and compartmentalisation determination to well control and drilling optimisation. The market for FPWD is developing rapidly with all major service companies providing their own implementations of the technology. The next step in the evolution of FPWD technology—sampling while drilling—is not commercially available yet, but this is just a matter of time. The case history presented in this extended abstract is an example of the application and lessons learned from the FPWD service used in one of the oil fields on the North West Shelf, Australia.

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