1887
Volume 39, Issue 2
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

The Barrow Group strata (Macedon Member, Pyrenees Member, and Barrow Group sandstones) of the Exmouth Sub-basin host significant accumulations of gas and liquid hydrocarbons. There is currently oil production from the Macedon sandstone at the Enfield Field and ongoing development drilling at the Stybarrow Field. Active appraisal and exploration is underway, including the multi-field Pyrenees Development. In the course of assessing these discoveries, BHP Billiton and its joint-venture partners have undertaken a hydrodynamic study in order to better understand the sealing mechanisms, the position of free-water levels (FWLs), and the likelihood of compartmentalisation within the discoveries.

Whilst the region is faulted with a predominant south-west-north-east grain, the potentiometric gradient is surprisingly flat indicating that the individual sands are hydraulically well connected. Other than the Macedon Gas Field, there is no pressure data that indicate intra-formational seals have been breached. Thus, top and bottom seal capacity is probably not limiting the pool sizes. Rather, structural spill points and fault seal capacity appear the significant factors in determining pool geometry, with the underlying aquifer being regionally connected around fault tips.

On the field-scale, the flat hydraulic gradient allows for the calculated FWLs to have a high confidence. Pressure data from the hydrocarbon phases indicate that in some cases, fault zones may compartmentalise a field into multiple pools. These areas are then targeted for additional focused geological analysis to reduce uncertainty in field compartmentalisation. The Macedon Gas Field, on the eastern edge of the play fairway, marks a change in the trapping character with intra-formational and fault seals having been breached resulting in a single continuous gas pool despite internal structural complexity. Stybarrow and Laverda-Skiddaw clearly occur as separate accumulations and the Stybarrow data define a single oil column in contrast to the potentially compartmentalized Laverda-Skiddaw field. Stybarrow represents an anomalously large oil column relative to other fields in the area and it is located on the low hydraulic head side of a sealing fault.

© 2008 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG08010
2008-06-01
2026-01-24

  • From This Site

    /content/journals/10.1071/EG08010
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Bachu S. 1995 Flow of variable-density formation water in deep sloping aquifers: review of methods of representation with case studies: Journal of Hydrology 164 19 38 doi:10.1016/0022-1694(94)02578-Y
    [Google Scholar]
  2. Bachu S. Burwash R. A. 1991 Regional-scale analysis of the geothermal regime in the Western Canada Sedimentary Basin: Geothermics 20 387 407 doi:10.1016/0375-6505(91)90028-T
    [Google Scholar]
  3. Bachu S. Michael K. 2002 Flow of variable-density formation water in deep sloping aquifers: minimizing the error in representation and analysis when using hydraulic-head distributions: Journal of Hydrology 259 49 65 doi:10.1016/S0022-1694(01)00585-6
    [Google Scholar]
  4. Bachu S. Ramon J. C. Villegas M. E. Underschultz J. R. 1995 Geothermal regime and thermal history of the Llanos Basin, Colombia: The American Association of Petroleum Geologists Bulletin 79 116 129
    [Google Scholar]
  5. Bailey R. W. Underschultz J. Dewhurst D. Kovack G. Mildren S. Raven M. 2006 Multi-disciplinary approach to fault and top seal appraisal; Pyrenees-Macedon oil and gas fields, Exmouth Sub-basin, Australian Northwest Shelf: Marine and Petroleum Geology 23 241 259 doi:10.1016/j.marpetgeo.2005.08.004
    [Google Scholar]
  6. Bekele E. B. Johnson M. Higgs W. 2001 Numerical modelling of overpressure generation in the Barrow Sub-basin, Northwest Australia: Australian Petroleum Production and Exploration Association Journal 41 595 607
    [Google Scholar]
  7. Brown A. 2003 a Capillary effects on fault-fill sealing: The American Association of Petroleum Geologists Bulletin 87 381 395
    [Google Scholar]
  8. Brown A. 2003 b Improved interpretation of wireline pressure data: The American Association of Petroleum Geologists Bulletin 87 295 311
    [Google Scholar]
  9. Dahlberg E. C. 1995, Applied hydrodynamics in petroleum exploration: Second edition edn: Springer-Verlag.
  10. Ementon N. , Hill R. , Flynn M. , Motta B. , and Sinclair S. 2004, Stybarrow oil field – from seismic to production, the integrated story so far: SPE paper 88574, SPE Asia Pacific Oil and Gas Conference Perth 2004.
  11. Hennig A. , Underschultz J. R. , and Otto C. J. 2002, Hydrodynamic analysis of the Early Cretaceous aquifers in the Barrow Sub-basin in relation to hydraulic continuity and fault seal In M. Keep and S. J. Moss eds., The Sedimentary Basins of Western Australia 3: Proceedings of the Petroleum Exploration Society of Australia Symposium; Perth, WA, 305–320.
  12. Hitchon B. Brulotte M. 1994 Culling criteria for “standard” formation water analyses: Applied Geochemistry 9 637 645 doi:10.1016/0883-2927(94)90024-8
    [Google Scholar]
  13. Otto C. Underschultz J. Hennig A. Roy V. 2001 Hydrodynamic analysis of flow systems and fault seal integrity in the Northwest Shelf of Australia: Australian Petroleum Production and Exploration Association Journal 41 347 365
    [Google Scholar]
  14. Scibiorski J. P. Micenko M. Lockhart D. 2005 Recent discoveries in the Pyrenees Member, Exmouth sub-Basin: A new oil play fairway: Australian Petroleum Production and Exploration Association Journal 45 233 251
    [Google Scholar]
  15. Sollie F. , and Rodgers S. 1994, Towards better measurements of logging depth: Society of Professional Well Log Analysts Thirty-Fifth Annual Logging Symposium Transactions D1–D15.
  16. Underschultz J. R. 2007 Hydrodynamics and membrane seal capacity: Geofluids 7 148 158 doi:10.1111/j.1468-8123.2007.00170.x
    [Google Scholar]
  17. Underschultz J. R. , Ellis G. K. , Hennig A. L. , Bekele E. , and Otto C. J. 2002, Estimating Formation Water Salinity from Wireline Pressure Data: Case Study in the Vulcan Sub-basin In M. Keep and S. J. Moss eds., The Sedimentary Basins of Western Australia 3: Proceedings of the Petroleum Exploration Society of Australia Symposium; Perth, WA, 285–303.
  18. Underschultz J. R. , Otto J. C. , and Bartlett R. 2005, Formation fluids in faulted aquifers: examples from the foothills of Western Canada and the North West Shelf of Australia In P. Boult and J. Kaldi eds., evaluating fault and cap rock seals. American Association of Petroleum Geologists, Hedberg Series, 2, 247–260.
  19. Veneruso A. F. , Erlig-Economides C. , and Petijean L. 1991, Pressure gauge specification considerations in practical well testing: 66th Annual Technical Conference and Exhibition of the Society of Petroleum Engineers; Dallas, Texas 865–878.
/content/journals/10.1071/EG08010
Loading
The hydrodynamics of fields in the Macedon, Pyrenees, and Barrow Sands, Exmouth Sub-basin, Northwest Shelf Australia: identifying seals and compartmentsFN1
Exploration Geophysics 39, 85 (2008); https://doi.org/10.1071/EG08010
/content/journals/10.1071/EG08010
/content/journals/10.1071/EG08010
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): hydrodynamics, seal analysis, Exmouth Sub-basin, fault seal, Carnarvon Basin, Barrow Group.

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error