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.

DEMETER HIGH RESOLUTION 3D SEISMIC SURVEY—REVITALISED DEVELOPMENT AND EXPLORATION ON THE NORTH WEST SHELF, AUSTRALIA

2006 ◽  
Vol 46 (1) ◽  
pp. 101 ◽  
Author(s):  
K.J. Bennett ◽  
M.R. Bussell
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
New Technologies ◽  
Seismic Survey ◽  
Future Application ◽  
3D Seismic ◽  
Gas Field ◽  
North West ◽  
The North ◽  
Exploration And Development

The newly acquired 3,590 km2 Demeter 3D high resolution seismic survey covers most of the North West Shelf Venture (NWSV) area; a prolific hydrocarbon province with ultimate recoverable reserves of greater than 30 Tcf gas and 1.5 billion bbls of oil and natural gas liquids. The exploration and development of this area has evolved in parallel with the advent of new technologies, maturing into the present phase of revitalised development and exploration based on the Demeter 3D.The NWSV is entering a period of growing gas market demand and infrastructure expansion, combined with a more diverse and mature supply portfolio of offshore fields. A sequence of satellite fields will require optimised development over the next 5–10 years, with a large number of wells to be drilled.The NWSV area is acknowledged to be a complex seismic environment that, until recently, was imaged by a patchwork of eight vintage (1981–98) 3D seismic surveys, each acquired with different parameters. With most of the clearly defined structural highs drilled, exploration success in recent years has been modest. This is due primarily to severe seismic multiple contamination masking the more subtle and deeper exploration prospects. The poor quality and low resolution of vintage seismic data has also impeded reservoir characterisation and sub-surface modelling. These sub-surface uncertainties, together with the large planned expenditure associated with forthcoming development, justified the need for the Demeter leading edge 3D seismic acquisition and processing techniques to underpin field development planning and reserves evaluations.The objective of the Demeter 3D survey was to re-image the NWSV area with a single acquisition and processing sequence to reduce multiple contamination and improve imaging of intra-reservoir architecture. Single source (133 nominal fold), shallow solid streamer acquisition combined with five stages of demultiple and detailed velocity analysis are considered key components of Demeter.The final Demeter volumes were delivered early 2005 and already some benefits of the higher resolution data have been realised, exemplified in the following:Successful drilling of development wells on the Wanaea, Lambert and Hermes oil fields and identification of further opportunities on Wanaea-Cossack and Lambert- Hermes;Dramatic improvements in seismic data quality observed at the giant Perseus gas field helping define seven development well locations;Considerably improved definition of fluvial channel architecture in the south of the Goodwyn gas field allowing for improved well placement and understanding of reservoir distribution;Identification of new exploration prospects and reevaluation of the existing prospect portfolio. Although the Demeter data set has given significant bandwidth needed for this revitalised phase of exploration and development, there remain areas that still suffer from poor seismic imaging, providing challenges for the future application of new technologies.

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.

Deep learning for multitrace sparse-spike deconvolution

Geophysics ◽  
2021 ◽  
pp. 1-64
Author(s):  
Xintao Chai ◽  
Genyang Tang ◽  
Kai Lin ◽  
Zhe Yan ◽  
Hanming Gu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Seismic Data ◽  
Resolution Enhancement ◽  
Parameter Tuning ◽  
Seismic Exploration ◽  
3D Seismic ◽  
Spatial Continuity ◽  
Additional Information ◽  
3D Data ◽  
3D Seismic Data

Sparse-spike deconvolution (SSD) is an important method for seismic resolution enhancement. With the wavelet given, many trace-by-trace SSD methods have been proposed for extracting an estimate of the reflection-coefficient series from stacked traces. The main drawbacks of the trace-by-trace methods are that they neither use the information from the adjacent seismograms and nor take full advantage of the inherent spatial continuity of the seismic data. Although several multitrace methods have been consequently proposed, these methods generally rely on different assumptions and theories and require different parameter settings for different data applications. Therefore, the traditional methods demand intensive human-computer interaction. This requirement undoubtedly does not fit the current dominant trend of intelligent seismic exploration. Therefore, we have developed a deep learning (DL)-based multitrace SSD approach. The approach transforms the input 2D/3D seismic data into the corresponding SSD result by training end-to-end encoder-decoder-style 2D/3D convolutional neural networks (CNNs). Our key motivations are that DL is effective for mining complicated relations from data, the 2D/3D CNNs can take multitrace information into account naturally, the additional information contributes to the SSD result with better spatial continuity, and parameter tuning is not necessary for CNN predictions. We report the significance of the learning rate for the training process's convergence. Benchmarking tests on the field 2D/3D seismic data confirm that the approach yields accurate high-resolution results that are mostly in agreement with the well logs; the DL-based multitrace SSD results generated by the 2D/3D CNNs are better than the trace-by-trace SSD results; and the 3D CNN outperforms the 2D CNN for 3D data application.

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.

SEISMIC DELINEATION OF STRUCTURE-CONTROLLED CARBONATE CEMENT AND POTENTIAL ECONOMIC IMPLICATIONS, ANGEL FIELD, NORTH WEST SHELF

1995 ◽  
Vol 35 (1) ◽  
pp. 280
Author(s):  
S. Ryan-Grigor ◽  
J.P. Schulz-Rojahn
Keyword(s):  
Seismic Data ◽  
High Amplitude ◽  
Fault System ◽  
3D Seismic ◽  
Economic Implications ◽  
Northern Margin ◽  
North West ◽  
The North ◽  
Migration Pathways ◽  
3D Seismic Data

Major carbonate-cemented zones occur in Late Jurassic Angel Formation sandstones of marine mass flow origin that contain large hydrocarbon reserves in the Angel Field, Dampier Sub-basin. Preliminary results suggest that poikilotopic dolomite cement is dominant. The carbonate-cemented zones are identifiable from wireline log response and 3D seismic data, and occur in discrete intervals with a cumulative thickness of approximately 165m at Angel-2. These intervals produce a zone of high amplitude reflections of about 100 ms two-way time. Field-wide seismic mapping indicates that these carbonate-cemented zones sharply abut the northern margin of a major east-west trending strike-slip fault system that traverses this field. The carbonate-cemented zones extend in a wedge-like shape towards the northeast and concentrate along the crest of the main structural trend.The results underscore the importance of 3D seismic data for a better estimation of reservoir risk and reserves in variably carbonate-cemented sandstones.The carbonate-cemented zones may represent a 'plume' related to migration of petroleum and/or carbon dioxide. Therefore delineation of major carbonate-cemented zones using seismic data may aid in the identification of petroleum migration pathways and pools in the North West Shelf. Alternatively, carbonate cements dissolved south of the major fault zone and possibly in downdip locations in which case dissolution pores may exist in these areas. Further research is required to evaluate these hypotheses.

The Brunei slide: A giant submarine landslide on the North West Borneo Margin revealed by 3D seismic data

2007 ◽  
Vol 246 (1) ◽  
pp. 9-23 ◽  
Author(s):  
M.J.R. Gee ◽  
H.S. Uy ◽  
J. Warren ◽  
C.K. Morley ◽  
J.J. Lambiase
Keyword(s):  
Seismic Data ◽  
Submarine Landslide ◽  
3D Seismic ◽  
North West ◽  
The North ◽  
3D Seismic Data

New insights into North Sea tunnel valley infill and genesis from high-resolution 3D seismic data

2020 ◽  
Author(s):  
James Kirkham ◽  
Kelly Hogan ◽  
Robert Larter ◽  
Ed Self ◽  
Ken Games ◽  
...  
Keyword(s):  
High Resolution ◽  
North Sea ◽  
Seismic Data ◽  
3D Seismic ◽  
Seismic Reflection Data ◽  
North West ◽  
The North ◽  
Reflection Data ◽  
Order Of Magnitude ◽  
Subglacial Meltwater

<p>Tunnel valleys are large (kilometres wide, hundreds of metres deep) channels incised into bedrock and soft sediments by the action of pressurised subglacial meltwater. Discovered over a century ago, they are common across large swathes of North-West Europe and North America. However, many aspects of tunnel valley formation, and the processes by which they are infilled, remain poorly understood. Here, we use new high-resolution 3D seismic reflection data, collected by the geohazard assessment industry, to examine the infill lithology and architecture of buried tunnel valleys located in the central North Sea. The spatial resolution of our seismic data (3.125-6.25 m bin size) represents an order of magnitude improvement in the data resolution that has previously been used to study tunnel valleys in this region, allowing us to examine their infill in unprecedented detail. Inside the tunnel valleys, we identify a suite of buried subglacial landforms, some of which have rarely been reported inside tunnel valleys before. These landforms include a 14-km-long system of segmented eskers, crevasse-squeeze ridges, subsidiary meltwater channels and retreat moraines. Their presence suggests that, in some cases, tunnel valleys in the North Sea were reoccupied by ice following their initial formation, casting doubt on hypotheses which invoke catastrophic releases of water to explain tunnel valley creation.</p>

ACQUISITION TECHNOLOGY OPENS UP DIFFICULT DATA AREAS FOR 3D EXPLORATION

2002 ◽  
Vol 42 (1) ◽  
pp. 607
Author(s):  
C.R.T Ramsden ◽  
A.S Long
Keyword(s):  
Data Quality ◽  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Cost Savings ◽  
3D Seismic ◽  
Single Source ◽  
North West ◽  
3D Data ◽  
Long Offset ◽  
Dual Source

3D seismic technologies have advanced rapidly during the 1990s. The new generation of seismic vessels such as the Ramform design with their massive towing capacities has changed the way in which modern seismic data is acquired. This has resulted in a large increase worldwide in the use of 3D seismic data during the exploration phase because of the reduction in the cost of 3D data. A statistical database has emerged showing that drilling on 3D data will double the commercial success rate compared to drilling on 2D data.Historically, dual-source acquisition has dominated exploration (by comparison to single-source acquisition) due to cost savings associated with the fact that singlesource acquisition implies a geophysical requirement to tow the streamers at half the separation of dual-source acquisition. Data quality associated with single-source acquisition, however, is typically much superior to dualsource data. The ability now to tow 12–16 streamers has reduced costs so that single-source acquisition is now cost effective. The surveys using single-source acquisition allow 3D data to be acquired with significantly higher trace densities and crew efficiencies than industry standard, and are called High Density 3D or HD3D. These surveys have benefits of increased fold, improved spatial resolution and improved imaging quality, and can now be routinely conducted, especially in difficult data areas.The North West Shelf of Australia is a difficult data area because of the presence of strong multiple noise trains that often mask or interfere with the primary reflections (Ramdsen et al, 1988). Standard multiple attenuation techniques have had only limited success. HD3D with its higher trace density and 40% improvement in signal-to-noise ratio has resulted in improved data quality in difficult data areas, and should result in data improvements on the North West Shelf as well.Furthermore, the Continuous Long Offset (CLO) recording technique using Ramform technology is a dualvessel operation that has demonstrated significant operational efficiency improvements in long offset (typically deep water/targets) 3D seismic acquisition. Survey turnaround times can be reduced by as much as half of those using conventional techniques. The CLO technique is particularly well suited for deepwater recording.

SEISMIC EXPRESSION OF ABNORMAL GEO-PRESSURE IN THE BARROW SUB-BASIN

2002 ◽  
Vol 42 (1) ◽  
pp. 547
Author(s):  
M. Urosevic ◽  
Li-Yun Fu ◽  
K.J. Dodds
Keyword(s):  
Pore Pressure ◽  
Research Effort ◽  
North West ◽  
The North ◽  
3D Data ◽  
Modelling Studies ◽  
Vsp Data ◽  
Using Data ◽  
Well Data ◽  
Relationship Of

Drilling uncertainties related to abnormal geopressure are common in the Barrow and Dampier Sub-basins of the North West Shelf. These uncertainties contribute to increased drilling risk and costs. There have been a number of published studies in this area which have been directed towards understanding the mechanisms and modelling of the expected pressures. These studies, however, have been in general isolated and have concentrated on non-seismic related methods. This paper provides an empirical analysis of the seismic response in an area with known variation of overpressure, and critically is integrated with a comprehensive research effort looking at aspects of overpressure from a laboratory, empirical and theoretical perspective.The study was conducted using data taken from permit WA-25-P (P25) in the Barrow Sub-basin. These data included 3D surface seismic and VSP, well logs, mud weight and pressure data from the wells. The results of a mineralogical analysis conducted on core samples and basin-wide geological modelling studies were also incorporated into the study. The Muderong Shale, which comprises the principal seal in the area and is believed to be overpressured was selected as the prime target for the analysis. Initially we assess the potential of existing methods, such as velocitybased methods, for remote prediction of excessive pore pressure in the area P25. This is extended to amplitude related effects involving an analysis of reflectivity in the presence of a velocity transition zone over the overpressured interval. Finally the relationship of well data, VSP and surface seismic derived attributes is described.The available data in the P25 area was sparse and consequently we could not rely on statistical based associations. Current industry methods that rely on a limited number of calibration points suggest that the application of either velocity or AVO based methods may produce unreliable predictions of pore pressure. Ambiguities in inferring overpressure introduced by a variable mineral composition of shales and the presence of a strong velocity gradient, which distorts the wave shape, reduces the reliability of these methods.A detailed analysis using VSP data acquired in a highly overpressured well was found to be crucial for understanding the response of various seismic attributes to changes in effective stress. This enabled us to propose a new qualitative, but efficient approach for remote prediction of overpressure, particularly suited for underexplored areas such as P25. The applicability of the method, which uses single and combined seismic sequence and trace multi-attributes to predict overpressured zones, is demonstrated with the Venture-Carey 3D data recorded in the Barrow Sub-basin.

ECONOMIC ADVANTAGES OF USING EXPLORATION 3D SEISMIC ON THE NORTH WEST SHELF

1996 ◽  
Vol 36 (1) ◽  
pp. 385
Author(s):  
O.A. Larsen ◽  
J. Winterhalder ◽  
J.S. Boardman ◽  
J.N.G. Smith
Keyword(s):  
Net Present Value ◽  
Comprehensive Evaluation ◽  
High Capacity ◽  
Development Program ◽  
Cost Effective ◽  
Oil Field ◽  
3D Seismic ◽  
North West ◽  
Oil Companies ◽  
The North

The development of high capacity seismic 3D vessels has been so rapid that the oil industry has yet to optimise its investment in seismic data. However, the oil companies are becoming increasingly aware of the financial benefits of multi-client surveys which maximise vessel efficiency and provide a comprehensive evaluation of large areas.Many oil companies continue to design exploration seismic programs based on 2D seismic and acquire 3D seismic surveys after drilling the exploration/discovery well and generally after at least one appraisal well. Such single client surveys are limited by expected field outlines, which results in high unit costs for the seismic and missed opportunities beyond these outlines.The immediate benefits identified from obtaining early 3D data include: a higher success rate, optimisation of well locations, more rapid and cost effective appraisal, earlier screening studies, and an advanced development program. The combination of these factors can accelerate production by up to 18 months.For the scenarios evaluated in this paper, the use of 3D seismic early in the exploration period translates into an increase in Net Present Value of A$18-33 million and Expected Monetary Value of A$50-58 million for a 50 MMBBL oil field.

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