Velocity anomalies and out-of-plane reflections in Barnicarndy 1, Canning Basin
Y. ZhanGeological Survey of Western Australia, 100 Plain Street, East Perth WA 6004, Australia. Email: alex.zhan@dmirs.wa.gov.au
The APPEA Journal 61(1) 271-290 https://doi.org/10.1071/AJ20082
Submitted: 14 January 2021 Accepted: 5 February 2021 Published: 2 July 2021
Abstract
Barnicarndy 1 was drilled as a stratigraphic well and penetrated 2585 m of clastic sedimentary rocks overlying an angular unconformity composed of Proterozoic dolomite basement near SSE end of the eponymous graben (previously known as the Waukarlycarly Embayment) of the Canning Basin. The post-drilling data exhibited several types of anomalies and inconsistencies, including ultra-slow velocity of the vertical seismic profile (VSP) within the top 210 m, substantially high velocity from 210 to 1390 m, poor synthetic–seismic correlation, and discrepancies between the prognosis and actual depths. The VSP shows that the uppermost sedimentary section has an average velocity of less than 1000 m/s, which is unrealistically slow and probably caused by a systematic time delay in the data acquisition. Such a delaying effect was removed when calculating the VSP interval velocity, which had reasonable consistencies with sonic velocity and lithological packages. The consistencies verify that the sections from 210 to 1390 m have high velocities that are beyond the range of offset wells at equivalent depths and do not follow an expected trend along most of the well trajectory. Quantitative analyses of multiple synthetic correlations suggest that the depth discrepancies in the prognosis are not related to pre-drilling seismic interpretation, as the two-way time picks for major boundaries mostly match what has been penetrated in Barnicarndy 1. Two thirds of the depth error for basement prognosis comes from the unexpected high velocity in the shallow formations. The velocity anomalies indicate that the Barnicarndy Graben possibly has a complex history of tectonic movement, and thick sections could have been eroded during the Late Triassic. The remaining discrepancy in depth prognosis for the basement is related to the out-of-plane seismic reflection near the SSE end of the graben. The steeply dipping basement causes out-of-plane issues for 2D seismic data, and the Kidson seismic survey images the shallower basement reflected from further south, rather than what is vertically below the survey route.
Keywords: Canning Basin, out-of-plane, seismic interpretation, sonic, tectonic movement, vertical seismic profile, VSP, Barnicarndy Graben, Western Australia.
Yijie Zhan graduated from China University of Geoscience (Beijing) with a BSc in 2005. He has worked on structural interpretation, fracture detection and reservoir modelling in various basins. He has published in English and Chinese on azimuthal anisotropy, forward modelling and characterisation of gas-bearing volcanoclastic and conventional reservoirs. He joined the Geological Survey of Western Australia’s Basin and Energy Geoscience group as Senior Geophysicist in 2011, and he is a member of PESA. |
References
Allen, K. A., Eder, J., and Tipps, R. D. (1971). Final report Canning Basin Anketell seismic survey (Projects 277 and 283); West Australian Petroleum Pty, Ltd. Geological Survey of Western Australia, Statutory petroleum exploration report, S614 A1, 152p.Buru Energy Limited (2013). Ungani and Ungani 1ST1 Well Completion Report Volume 2 - Derivative Data: Exploration Permit EP 391 Canning Basin, Western Australia. Geological Survey of Western Australia, Statutory petroleum exploration report W21513 A3, 153p.
Buru Energy Limited (2014). Asgard 1 Well Completion Report Volume 2 - Derivative Data: Exploration Permit EP 371 Canning Basin, Western Australia. Geological Survey of Western Australia, Statutory petroleum exploration report W21543 A2, 308p.
Carr, L. K., Edwards, D. S., Southby, C., Henson, P., Haines, P., Normore, L., Zhan, A., Brooks, D., MacFarlane, S., Boreham, C. J., Grosjean, E., Mory, A. J., Wang, L., and Gunning, M.-E. (2020). Kidson Sub-basin seismic survey and Waukarlycarly 1 stratigraphic well: an acquisition program for evaluating Canning Basin petroleum systems. In ‘Exploring for the Future: Extended Abstracts’ (Eds K. Czarnota, S. Abbott, M. Haynes, N. Kositcin, A. Ray and E. Slatter). Geoscience Australia, Canberra
Command Petroleum N.L. (1989). Frankenstein-1, Canning Basin, well completion report, EP 232: Command Petroleum N.L. Geological Survey of Western Australia, Statutory petroleum exploration report S3417 A2V1, 90p.
Drummond, B. J., Hobbs, R. W., and Goleby, B. R. (2004). The effects of out-of-plane seismic energy on reflections in crustal-scale 2D seismic sections. Tectonophysics 388, 213–224.
| The effects of out-of-plane seismic energy on reflections in crustal-scale 2D seismic sections.Crossref | GoogleScholarGoogle Scholar |
Forman, D. J. and Wales, D. W. (1981). Geological evolution of the Canning Basin, Western Australia. Bureau of Mineral Resources, Geology and Geophysics, Bulletin 210, 91p.
Fraser, A. R. (1976). Gravity provinces and their nomenclature. BMR Journal of Australian Geology and Geophysics 1, 350–352.
Frogtech Geoscience (2017). Canning Basin SEEBASE study and GIS data package. Geological Survey of Western Australia, Report 182, 297p.
Geological Survey of Western Australia (GSWA) (2017). 1:500 000 tectonic units of Western Australia, 2017. Geological Survey of Western Australia. Available at https://dmpbookshop.eruditetechnologies.com.au//product/1500-000-tectonic-units-of-western-australia-2017.do
Geological Survey of Western Australia (GSWA) (2020). Gravity anomaly grid (400 m) of Western Australia (2020 — version 1). Geological Survey of Western Australia, Digital data layer, available at https://www.dmp.wa.gov.au/Geological-Survey/Regional-geophysical-survey-data-1392.aspx
Hocking, R. M. (1994a). Basin subdivisions of Western Australia. In ‘Subdivisions of Western Australian Neoproterozoic and Phanerozoic sedimentary basins’. Geological Survey of Western Australia, Record 1994/4, Plate 1.
Hocking, R. M. (1994b). Subdivisions of Western Australian Neoproterozoic and Phanerozoic sedimentary basins. Geological Survey of Western Australia, Record 1994/4, 85p.
Hunt Oil Company of Australia (1997). Final report, Waukarlycarly seismic survey interpretation; Hunt Oil Company of Australia. Geological Survey of Western Australia, Statutory petroleum exploration report, S10316 A5 (Open file).
Iasky, R. P. (1990). Officer Basin. In ‘Geology and mineral resources of Western Australia’. Western Australia Geological Survey, Memoir 3, pp. 362–380.
Kennard, J. M., Jackson, M. J., Romine, K. K., Shaw, R. D., and Southgate, P. N. (1994). Depositional sequences and associated petroleum systems of the Canning Basin, WA. In ‘The Sedimentary Basins of Western Australia’. (Eds P. G. Purcell and R. R. Purcell) pp. 657–676. (Petroleum Exploration Society of Australia, Western Australian Branch, Perth, WA.)
Kopty, Z. (2020). Downhole seismic logging, Waukarlycarly 1 VSP report, Hiseis Pty Ltd, WAPIMS. Available at https://wapims.dmp.wa.gov.au/WAPIMS/
Normore, L. S., and Rapaic, M. (2020). Waukarlycarly 1 basic data well completion report: Geological Survey of Western Australia, Report 206, 14p.
Roach, I. C., Costelloe, M. T., and Whitaker, A. J. (2010). Previous and concurrent work. In ‘Geological and energy implications of the Paterson airborne electromagnetic (AEM) survey, Western Australia’ Geoscience Australia, Record 2010/12. (Ed. IC Roach) pp. 29–47. Available at https://d28rz98at9flks.cloudfront.net/70302/Rec2010_012.pdf
Sorensen, M. K. (2015). Mud-filtrate correction of sonic logs by fluid substitution: Modulus and pore-fluid coupling by pore-filling clay. Technical University of Denmark, Department of Civil Engineering.
Southby, C., Carr, L., Henson, P., Haines, P., Zhan, A., Anderson, J., MacFarlane, S., Fomin, T., and Costelloe, R. (2019). Exploring for the future: Kidson Sub-basin seismic interpretation. ASEG Extended Abstracts 1, 1–3.
| Exploring for the future: Kidson Sub-basin seismic interpretation.Crossref | GoogleScholarGoogle Scholar |
Velseis Processing Pty Ltd (editor) (2019). Seismic Data Processing Report: 2018 Kidson Sub-basin Deep Crustal Seismic Survey, Land 2D, 42p.
Walker Petrophysics (2020). Petrpophysical Evaluation, Waukarlycarly 1. Walker Petrophysics Pty Ltd, WAPIMS. Available at https://wapims.dmp.wa.gov.au/WAPIMS/
Zhan, Y. (2014). 2D seismic interpretation of the Harvey area, southern Perth Basin, Western Australia. Geological Survey of Western Australia, Record 2014/7, 25p.
Zhan, Y. (2017). Canning Coastal seismic survey — an overview of the Canning Basin. Geological Survey of Western Australia; Record 2017/5, 29p.
Zhan, Y. (2018). A seismic interpretation of the southwestern Canning Basin, Western Australia. Geological Survey of Western Australia; Report 178, 34p.
Zhan, Y. (2019a). A seismic interpretation of the Broome Platform, Willara Sub-basin and Munro Arch of the Canning Basin, Western Australia. Geological Survey of Western Australia; Report 193, 43p.
Zhan, Y. (2019b). Seismic interpretation of salt occurrences in the southern Canning Basin, Western Australia. In ‘The Sedimentary Basins of Western Australia V, Proceedings of the Petroleum Exploration Society of Australia Symposium, Perth, Western Australia, 2–5 September 2019 (Eds M. Keep and S. J. Moss) p. 15. (Petroleum Exploration Society of Australia)
Zhan, Y., and Haines, P. W. (2021). Kidson Sub-basin Seismic Survey – A panorama of the southern Canning Basin: Geological Survey of Western Australia; Report 216, in press.
Zhan, Y., and Mory, A. J. (2013). Structural interpretation of the northern Canning Basin, Western Australia. In ‘The Sedimentary Basins of Western Australia, West Australian Basins Symposium, Perth, 18–21 August 2013. (Eds M. Keep and S. J. Moss) 18p. (Petroleum Exploration Society of Australia).
