LEGENDRE: MATURATION OF A MARGINAL OFFSHORE OIL DISCOVERY TO DEVELOPMENT PROJECT

1999 ◽  
Vol 39 (1) ◽  
pp. 504
Author(s):  
J.M. Willetts ◽  
D.J. Mason ◽  
L. Guerrera ◽  
P. Ryles
Keyword(s):  
Joint Venture ◽  
Development Planning ◽  
Development Project ◽  
Horizontal Drilling ◽  
North West ◽  
The North ◽  
Simulation Techniques ◽  
Production Wells ◽  
Light Oil ◽  
Offshore Oil

Commercialisation of the Legendre hydrocarbon resources represents the culmination of over 30 years of exploration and appraisal and more recent development planning, following the discovery by the first well to be flow-tested on the North West Shelf, Legendre–1, in 1968. By application of 3D seismic, reservoir modelling and simulation techniques, horizontal drilling and innovative development options, the WA-l-P Joint Venture is confident of achieving an economic return on a relatively small resource base.The two separate accumulations, Legendre North and Legendre South, are together expected to contain some 14 million m3 (90 MMSTB) of oil-in-place. The oil column in the northern accumulation is 45 m at its maximum, whilst a 20 m column is present in the southern accumulation. Reservoir quality is generally very good with mostly massive sandstones with little or no internal stratification. The reservoir contains a light oil and aquifer support is expected from communication with the underlying Angel Formation sandstones.The subsurface development plan has been designed to optimise the recovery of the oil in place in the two accumulations. Production wells with horizontal sections of 750 m will be used to minimise drawdown and ensure good sweep. Production is expected at a plateau rate of 4,800 to 6,400 m3/d (30−40,000 BOPD). Produced gas will be disposed of by means of a re-injection well downdip of the producers.

JOHN BROOKES GAS FIELD DEVELOPMENT

2005 ◽  
Vol 45 (1) ◽  
pp. 13
Author(s):  
A.J. McDiarmid ◽  
P.T. Bingaman ◽  
S.T. Bingham ◽  
B. Kirk-Burnnand ◽  
D.P. Gilbert ◽  
...  
Keyword(s):  
Low Cost ◽  
Time Frame ◽  
Gas Production ◽  
Gas Field ◽  
Initial Development ◽  
North West ◽  
Field Development ◽  
The North ◽  
Production Wells ◽  
Development Approach

The John Brookes gas field was discovered by the drilling of John Brookes–1 in October 1998 and appraisal drilling was completed in 2003. The field is located about 40 km northwest of Barrow Island on the North West Shelf, offshore West Australia. The John Brookes structure is a large (>90 km2) anticline with >100 m closure mapped at the base of the regional seal. Recoverable sales gas in the John Brookes reservoir is about 1 Tcf.Joint venture approval to fast track the development was gained in January 2004 with a target of first gas production in June 2005. The short development time frame required parallel workflows and use of a flexible/low cost development approach proven by Apache in the area.The John Brookes development is sized for off-take rates up to 240 TJ/d of sales gas with the development costing A$229 million. The initial development will consist of three production wells tied into an unmanned, minimal facility wellhead platform. The platform will be connected to the existing East Spar gas processing facilities on Varanus Island by an 18-inch multi-phase trunkline. Increasing the output of the existing East Spar facility and installation of a new gas sweetening facility are required. From Varanus Island, the gas will be exported to the mainland by existing sales gas pipelines. Condensate will be exported from Varanus Island by tanker.

NORTH WEST SHELF 3-D SEISMIC—A DECADE OF DEVELOPMENTS

1993 ◽  
Vol 33 (1) ◽  
pp. 315
Author(s):  
P.S. Vaughan
Keyword(s):  
Joint Venture ◽  
Spatial Sampling ◽  
Seismic Surveys ◽  
North West ◽  
The North ◽  
Technological Developments

Woodside as Operator, on behalf of three Joint Venture groups, over the last decade has acquired eight 3-D seismic surveys covering some 4 600 km2 over the Rankin Trend and Dampier Sub-Basin Production Licences and Exploration Permits on the North West Shelf of Australia. This area represents approximately 45 per cent coverage of the present Woodside operated acreage in the area. The acquisition, processing and interpretation technology and also the benefits derived from the 3-D technique have changed remarkably since the first North West Shelf 3-D survey in 1981. This paper focusses on the main technological developments in 3-D seismic, particularly involving multi-source and streamer technology, increased spatial sampling and interpretation techniques which have changed the role of 3-D seismic in Exploration strategies through the 1980s and into the 1990s.

A NEW TECTONO-STRATIGRAPHIC SYNTHESIS OF THE NORTH WEST CAPE AREA

1991 ◽  
Vol 31 (1) ◽  
pp. 154 ◽  
Author(s):  
R.J. Malcolm ◽  
M.C. Pott ◽  
E. Delfos
Keyword(s):  
Seismic Data ◽  
Joint Venture ◽  
Lateral Displacement ◽  
Landsat Imagery ◽  
Block Rotation ◽  
Surface Mapping ◽  
North West ◽  
The North ◽  
Oil Flow ◽  
Transfer Faults

The North West Cape area in the Exmouth Sub-basin was the site of the first onshore oil flow in Australia at Rough Range-1 in 1953. Subsequently, exploration focused on two large surface anticlines, Cape Range and Rough Range. By 1984, 30 unsuccessful wells had made it clear that the subsurface was far more complex than indicated by the surface mapping and limited seismic data. A detailed reappraisal of the subsurface structure and stratigraphy was needed.A joint venture group operated by Ampol Exploration began a new phase of exploration by recording over 1200 km of seismic data, both regional and detailed, between 1985 and 1989. An integrated interpretation of seismic data, well information and Landsat imagery has improved the understanding of structural and stratigraphic complexities and has given direction to the current exploration effort.Five of the most significant tectonic episodes to affect the North West Cape area have been recognised. They are Late Carboniferous and Early Jurassic (Sinemurian) rifting phases, Callovian-Oxfordian and Berriasian-Valanginian syn-rift pulses related to break-up and, finally, structural inversion in the Late Miocene. Each of these episodes is associated with characteristic structural styles and stratigraphic sequences.Significant lateral displacement along transfer faults during Sinemurian rifting and again during the Berriasian- Valanginian syn-rift pulse has resulted in the formation of tear faults that swing westward and merge with the plane of the transfer faults. Fault-block rotation and uplift associated with these tear faults provide potential structural and stratigraphic traps. The influence that transfer faults have on the hydrocarbon prospectivity of the North West Cape area has been recognised, including their role in the distribution of reservoir and source rocks.These tectono-stratigraphic concepts have provided a sound framework for future exploration in the North West Cape area, and may have implications for hydrocarbon prospectivity in other parts of the North West Shelf and on passive margins elsewhere.

THE GOLDFIELDS GAS PIPELINE: 'OPENING A NEW FRONTIER'

1996 ◽  
Vol 36 (1) ◽  
pp. 599
Author(s):  
B.M. Ride
Keyword(s):  
Joint Venture ◽  
Major Effect ◽  
Gas Pipeline ◽  
Liquid Fuels ◽  
Mining Operations ◽  
Simple Method ◽  
North West ◽  
Demand Growth ◽  
The North ◽  
New Frontier

Gas exploration and development in the northwest Pilbara in WA has increased due to the commitment of the Goldfields Gas Transmission Joint Venture to a 1,380 km gas pipeline linking the north west Pilbara to the east Pilbara iron ore region and the northern and central Goldfields. Construction of the GGT pipeline was approved in January 1995 and it is expected the pipeline will be servicing major mining operations in Newman, Mt Keith, Leinster and Kalgoorlie by August 1996. Other existing mining operations located near the pipeline are expected to convert from distillate for power station fuel to gas in 1996-97. Major new mining prospects in these highly prospective minerals provinces also offer potential for increased gas demand and GGT Pipeline throughput.The commercial arrangements for GGT Pipeline services are the first in Australia to be offered under the open access arrangements espoused by the Federal and WA Governments, and have set a benchmark for other pipelines in Australia. The innovative distance related pipeline tariff arrangements offer prospective gas shippers a simple method for evaluating use of the GGT pipeline and securing gas transmission services.The GGT Pipeline has had and will continue to have a major effect on the WA gas scene, stimulating gas exploration by capturing an established base load energy market currently dependent on liquid fuels and stimulating further WA gas demand growth.

THE DEVELOPMENT OF GORGON AREA GAS

2002 ◽  
Vol 42 (2) ◽  
pp. 113
Author(s):  
I.J. Grose
Keyword(s):  
Natural Gas ◽  
Environmental Performance ◽  
Joint Venture ◽  
Unit Cost ◽  
Clean Energy ◽  
North West ◽  
Design Concepts ◽  
The North ◽  
Competitive Prices ◽  
Exxon Mobil

Australia will increasingly need to turn to natural gas to offset declining oil production and meet an expanding global need for clean energy. The Gorgon Development Joint Venture Participants, (ChevronTexaco/Exxon- Mobil/Shell), are poised to develop the significant Gorgon gas reserves located 130 km offshore the North West Australian coast to help fulfil this need.The Gorgon Development has access to extensive proved reserves of 13.8 Tcf and a development plan that can supply gas to a Barrow Island landfall at world competitive prices. Several concepts are being considered for development of the Gorgon reserves.Technology will play a key role, with the extensive use of subsea production facilities and innovative LNG design concepts being considered.The focus is on a design that would have a low unit cost and also provide new benchmarks in safety and environmental performance. The development of the Gorgon reserves could also facilitate the establishment of other gas-based industries in Western Australia and offers the opportunity for new gas-to-liquid (GTL) plants to lead Australia’s transition to a gas-based economy.The Gorgon Development is expected to attract nearly A$4 billion investment for an LNG development and a further A$2 billion for a major industrial gas consumer. Total export income could reach A$2,500 million per year for 30 years.

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.

NEW TECHNOLOGY—A MAJOR IMPACT ON A PRODUCING FIELD: NORTH RANKIN GAS FIELD, NORTH WEST SHELF, AUSTRALIA

1992 ◽  
Vol 32 (1) ◽  
pp. 20
Author(s):  
L. Tilbury ◽  
T. Barter
Keyword(s):  
New Technology ◽  
Development Planning ◽  
Geological Structure ◽  
Lower Jurassic ◽  
Production Performance ◽  
Amplitude Analysis ◽  
Gas Field ◽  
North West ◽  
The North ◽  
Drilling Technology

New technology, especially the significant advances in 3D seismic interpretation techniques and drilling technology, has had a major impact on the development planning for the North Rankin Field.Significant advances have been made through the application of: horizon attribute processing, seismic amplitude analysis and long-reach drilling technology.Horizon attribute processing, including image processing techniques, has led to a better understanding of the structurally complex region on the northern flank of the field. These studies, coupled with new geological concepts related to opposing fault regimes, have concluded that good reservoir communication should exist across a fault zone previously thought to subdivide the field into compartments. The drilling of expensive, long-reach wells into the northern sector has thus been deferred, and may never be required, because of the newly developed structural model.Seismic amplitude analysis, coupled with geological modelling, upgraded the North Rankin West area and culminated in the recent significant appraisal/development well NRA22. This well was drilled from the North Rankin 'A' (NRA) platform to a target outside the main North Rankin Field in the adjacent Searipple Graben. NRA22 encountered well developed gas-bearing sands of Bathonian age which flowed at high rates (140 MMSCFGD).The application of long-reach drilling technology within Woodside has also had significant impact on development planning. The original development plan for North Rankin included a second platform in the northeast of the field. Better than expected production performance from NRA, related to across-fault reservoir communication, removed the necessity for a second platform. Large gas reserves in the Lower Jurassic 'NC' unit in the northeast have, however, required dedicated wells to improve ultimate recovery from this unit. The drilling of long-reach wells (at record drift) into the NC unit has provided better access to these reserves.Although North Rankin has been producing for over seven years with a total of 23 development wells drilled, understanding of the geological structure is still being improved by using new technology and ideas.

SEISMIC AMPLITUDE ANALYSIS: AN END TO FIELD APPRAISAL?

1988 ◽  
Vol 28 (1) ◽  
pp. 144
Author(s):  
Larry A. Tilbury ◽  
Philip M. Smith
Keyword(s):  
Seismic Reflection ◽  
Development Planning ◽  
Late Triassic ◽  
Amplitude Analysis ◽  
Gas Field ◽  
North West ◽  
Field Development ◽  
Seismic Amplitude ◽  
The North ◽  
Prediction Techniques

The success of lateral prediction techniques based on seismic reflection amplitude analysis has had a significant impact upon recent appraisal and development planning strategies in the Coodwyn Gas Field, offshore north-western Australia.The Coodwyn structure is one of a series of major tilted fault blocks on the Rankin Trend. The gently dipping reservoir sequence of Late Triassic to earliest Jurassic age is truncated by a major erosional unconformity and is overlain by sealing Cretaceous sediments. It is situated some SO kilometres west- south-west of the producing North Rankin Gas Field, to which it bears a striking resemblance in structural form and reservoir stratigraphy. Eight appraisal wells have been drilled in and around the field since its discovery in 1971. The most recent appraisal drilling campaign was designed to test a possible northern extension of the field within a stratigraphically younger reservoir sequence than that previously seen. The success of this campaign was such that the northern Coodwyn reservoirs are now being evaluated as possible candidates for development from a Coodwyn Platform to provide gas for the North West Shelf Project - one of the largest and most ambitious natural resource developments yet undertaken in Australia.During the latest campaign it was confirmed that seismic reflection amplitudes at the Main Unconformity were directly related to the lithology and fluid content of the subcropping reservoir sequence. This has allowed the gas-bearing sands to be mapped across the field with far greater confidence than was previously possible, obviating the need for further appraisal drilling. In fact, Coodwyn -10, a well proposed to intersect the unappraised upper F sands, was not drilled because of the confidence placed in the amplitude map.The amplitude map was used extensively during the 1986 drilling campaign, for refining the structural interpretation of the field, and during the recent Goodwyn Field development planning for the targeting of notional development wells from possible platform locations.

Seabirds at Risk around Offshore Oil Platforms in the North-west Atlantic

2001 ◽  
Vol 42 (12) ◽  
pp. 1285-1290 ◽  
Author(s):  
Francis K Wiese ◽  
W.A Montevecchi ◽  
G.K Davoren ◽  
F Huettmann ◽  
A.W Diamond ◽  
...  
Keyword(s):  
At Risk ◽  
North West ◽  
Oil Platforms ◽  
The North ◽  
Offshore Oil Platforms ◽  
Offshore Oil
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