The challenges of seismic acquisition in a remote and sensitive marine environment: Scott Reef, Western Australia

2009 ◽  
Vol 49 (2) ◽  
pp. 573
Author(s):  
Mark Taylor ◽  
Nick Fitzgerald ◽  
Jeremy Fitzpatrick ◽  
Ralph Weiss
Keyword(s):  
Western Australia ◽  
Seismic Survey ◽  
Ocean Bottom ◽  
Outer Continental Shelf ◽  
Gas Field ◽  
Narrow Channels ◽  
Reef Lagoon ◽  
The North ◽  
Seismic Acquisition ◽  
Water Depths

Woodside Energy Ltd, as operator of the Browse LNG Development, recently acquired two seismic surveys at Scott Reef, Western Australia. The surveys were important steps towards acquiring full seismic coverage over the Torosa gas field, part of which underlies Scott Reef The Maxima 3D marine seismic survey, conducted in late 2007, was a conventional towed streamer survey. This was followed in May 2008 by the Gigas 2D transition zone survey in the shallow waters of north Scott Reef, and Woodside’s first experience with ocean bottom cable (OBC) seismic technology. Each survey presented unique challenges during the planning, regulatory approval and acquisition stages. Scott Reef comprises two coral atolls located on the outer continental shelf of northwest Australia, approximately 400 km north of Broome. The only permanently emergent land is a small sand cay (Sandy Islet, Fig. 1), although the reef crests of both atolls are exposed at low tide. Outside the reefs the seafloor drops away rapidly, with water depths of about 350 m to the east, increasing to more than 1,000 m to the west. South Scott Reef lagoon is open to the north, with water depths increasing to about 50 m before deepening abruptly into the channel between the two reefs. North Scott Reef lagoon is shallower—generally less than 25 m—and is connected to the ocean by two narrow channels. Semi-diurnal tides with a range of up to 4.6 m produce strong tidal currents in and near these channels. Small, steep-sided coral heads, or bombies, are common throughout the lagoons, especially in water less than 25 m deep.

IMPROVEMENTS IN SEISMIC IMAGING, IO JANSZ GAS FIELD NORTH WEST SHELF, AUSTRALIA

2006 ◽  
Vol 46 (1) ◽  
pp. 135
Author(s):  
J. Hefti ◽  
S. Dewing ◽  
C. Jenkins ◽  
A. Arnold ◽  
B.E. Korn
Keyword(s):  
Image Quality ◽  
Processing Parameters ◽  
Interdisciplinary Teams ◽  
Seismic Survey ◽  
Gas Field ◽  
North West ◽  
The North ◽  
Seismic Acquisition ◽  
History Of ◽  
Close Cooperation

The Io Jansz gas field is situated in the Carnarvon Basin on the North West Shelf of Australia. It is Australia’s largest gas field, estimated to hold over 20 TCF of gas reserves and covering an area of over 2000 km2. Following a series of appraisal wells and a 3D seismic survey, this field is moving rapidly towards development. Image quality of the 3D provided significant uplift over existing 2D surveys in the area. Expectations for resolution and business targets have been met through careful planning and the provision of staged deliverables.Despite the exceptional data quality, a number of technical challenges were encountered that led to operational changes and adaptations by the project team. Source height statics and severe image distortion due to overburden are examples of some of the challenges addressed. Consideration of the exploration history of this field and its associated imaging gives insight into the improvements in image quality that can be realised by careful selection of acquisition and processing parameters, high levels of quality control (QC) and modern processing algorithms. The ultimate success of this project was achieved through close cooperation within interdisciplinary teams comprised of partner technical staff and the seismic acquisition and processing contractor.

Introduction to this special section: Acquisition and sensing

2019 ◽  
Vol 38 (9) ◽  
pp. 670-670
Author(s):  
Margarita Corzo ◽  
Tim Brice ◽  
Ray Abma
Keyword(s):  
Special Section ◽  
Seismic Survey ◽  
Ocean Bottom ◽  
Total Cost ◽  
Small Boat ◽  
Air Gun ◽  
Seismic Acquisition ◽  
The Cost ◽  
Seismic Images

Seismic acquisition has undergone a revolution over the last few decades. The volume of data acquired has increased exponentially, and the quality of seismic images obtained has improved tremendously. While the total cost of acquiring a seismic survey has increased, the cost per trace has dropped precipitously. Land surveys have evolved from sparse 2D lines acquired with a few dozen receivers to densely sampled 3D multiazimuth surveys. Marine surveys that once may have consisted of a small boat pulling a single cable have evolved to large streamer vessels pulling multiple cables and air-gun arrays and to ocean-bottom detectors that require significant fleets to place the detectors, shoot the sources, and provide support. These surveys collect data that are wide azimuth and typically fairly well sampled.

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.

DEVELOPMENT OF THE NORTH RANKIN FIELD, NORTH WEST SHELF, AUSTRALIA

1983 ◽  
Vol 23 (1) ◽  
pp. 164
Author(s):  
M. David Agostini
Keyword(s):  
Seismic Survey ◽  
Process Equipment ◽  
Two Phase ◽  
Gas Field ◽  
North West ◽  
The North ◽  
Christmas Trees ◽  
High Level ◽  
Inflow Performance ◽  
Standard Steel

The North Rankin gas field discovered in 1971, has been evaluated by a series of appraisal wells and refinement of this is underway through the use of a 3D seismic survey. Extensive production testing on two wells was used to establish reservoir fluid characteristics, inflow performance and to predict reservoir behaviour.The North Rankin 'A' platform has been constructed of a standard steel jacket design. Components of the structure were built in Japan, Singapore, Geraldton, Jervoise Bay and Adelaide. Provision exists for 34 wells to be drilled from the structure to exploit the southern end of the North Rankin field.Simultaneous drilling and producing activities are planned, requiring well survey and deviation control techniques that will provide a high level of confidence. Wells will be completed using 7 inch tubing, fire resistant christmas trees, and are designed to be produced at about 87 MMSCFD on a continuous basis. Process equipment on this platform is designed to handle 1200 MMSCFD and is intended primarily to dry the gas and condensate and to transfer gas and liquid to shore in a two phase 40 inch pipeline. The maintenance of offshore equipment is being planned to maximise the ratio between planned and unplanned work.The commencement of drilling activities is planned for mid 1983, with commissioning of process equipment occurring in the second quarter of 198 The North Rankin 'A' platform will initially supply the WA market at some 400 MMSCFD offshore gas rate, requiring 7 wells. The start of LNG exports is planned for April 1987. The intial gas for this will be derived from the North Rankin 'A' platform.

Ocean Bottom Node (OBN) seismic survey at Gorgon Gas Field

2017 ◽  
Vol 57 (2) ◽  
pp. 726
Author(s):  
Ronald Cupich ◽  
Birgit Cropp
Keyword(s):  
Seismic Survey ◽  
Ocean Bottom ◽  
Gas Field

Improvements in development strategy for the Stag Oil Field, North West Shelf, Australia—implications for production success and drilling risk minimisation

2012 ◽  
Vol 52 (2) ◽  
pp. 657
Author(s):  
Paul Anderson ◽  
Paul Bingaman ◽  
Sam Betts ◽  
Kyle Graves ◽  
Fred Fernandes ◽  
...  
Keyword(s):  
Development Strategy ◽  
Oil Field ◽  
Seismic Survey ◽  
Ocean Bottom ◽  
Injection Wells ◽  
Horizontal Drilling ◽  
North West ◽  
The North ◽  
Avo Inversion ◽  
Water Breakthrough

Located on the North West Shelf of Western Australia, the Stag Oil field has proven to be a prolific reservoir, having produced more than 55 million barrels (MMbbls) of oil since 1998. This has not been without its challenges, however; with premature water breakthrough from injection wells occuring in several wells, potentially stranding large volumes of oil in the ground. Using the multicomponent processing and joint amplitude-versus-offset (AVO) inversion of an ocean bottom cable (OBC) seismic survey acquired in late 2007, new light has been shed on the distribution of unswept oil. This data has led to the succesful drilling of six wells and a marked increase in field production. Additionally, the seismic data has also been used to minimise drilling risks by using seismic coherency to steer the well around potential problems with a significant impact on well costs due to reduction of wellbore problems associated with horizontal drilling in the Muderong shale. To date, four wells have been drilled using this technique, resulting in a significant decrease in non-productive time while drilling during the most recent drilling campaign, which has a significant impact upon the profitability of these late-stage development wells.

The Johnston Gas Field, Blocks 43/26a, 43/27a, UK Southern North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 749-759 ◽  
Author(s):  
David E. Lawton ◽  
Paul P. Roberson
Keyword(s):  
North Sea ◽  
Development Plan ◽  
Seismic Survey ◽  
3D Seismic ◽  
Seismic Attribute ◽  
Gas Field ◽  
Southern North Sea ◽  
North East ◽  
The North ◽  
The Uk

abstractThe Johnston Field is a dry gas accumulation located within blocks 43/26a and 43/27a of the UK Southern North Sea. The discovery well was drilled in 1990 and after the drilling of one appraisal well in 1991, a development plan was submitted and approved in 1993. Initially two development wells were drilled from a four slot sub-sea template, with commercial production commencing in October 1994. A further horizontal development well was added to the field in 1997.The field has a structural trap, fault bounded to the SW and dip-closed to the north, east and south. This field geometry has been established using high quality 3D seismic data, enhanced by seismic attribute analysis. The sandstone reservoir interval consists of the Early Permian, Lower Leman Sandstone Formation of the Upper Rotliegend Group. This reservoir consists of a series of interbedded aeolian dune, fluvial, and clastic sabkha lithofacies. The quality of the reservoir is variable and is principally controlled by the distribution of the various lithofacies. The top seal and fault bounding side seal are provided by the overlying clay stone of the Silverpit Shale Formation and the evaporite dominated Zechstein Supergroup.The field has been developed using a phased development plan, with the acquisition of a 3D seismic survey allowing for the optimized drilling of a high deliverability horizontal well.Current mapped gas initially-in-place estimates for the field are between 360 and 403 BCF, with an estimated recovery factor of between 60 and 75%.

PERTH BASIN REJUVENATED

1992 ◽  
Vol 32 (1) ◽  
pp. 33 ◽  
Author(s):  
Peter B. Hall ◽  
Robert L. Kneale
Keyword(s):  
Natural Gas ◽  
Western Australia ◽  
Market Access ◽  
Field Size ◽  
Gas Field ◽  
North West ◽  
The North ◽  
New Concepts ◽  
Technological Developments ◽  
Gas Market

The northern Perth Basin is an area where recent seismic advances combined with new geological insight, have led to exploration success with a significant new gas field discovery at Beharra Springs and a number of other minor discoveries. This paper outlines 'new concepts' with regard to stratigraphy and structure and how this has been balanced with the commercial environment to rejuvenate exploration in the northern Perth Basin. The Perth Basin is unique in Australia, as running through the middle of the Basin is the West Australian Natural Gas (WANG) pipeline which will be operating at approximately 26 per cent of its capacity in 1992. With the deregulation of the natural gas market in 1988, supply of gas to the Western Australian market via the State Energy Commission of Western Australia (SECWA) pipeline from the Carnarvon Basin, and in particular, the North West Shelf project, can now be balanced with supply from the onshore Perth Basin carried by the WANG pipeline.The minimum economically viable gas field in the northern Perth Basin is calculated to be 15 BCF (16.05 PJ) and the expected median field size is 50 BCF (53.5 PJ) of recoverable gas. Based on the historical success rate of one in eight, typical finding costs are 12 c/MCF (12 c/GJ).In the 1990/91 financial year, eight onshore exploration wells were drilled in Western Australia of which five were drilled in the northern Perth Basin. Provided the market access and opportunities remain, it is anticipated that the recent technological developments will sustain exploration and development of the onshore northern Perth Basin.

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