The Nappamerri Trough, Cooper Basin unconventional plays: proving a hypothesis
C. Trembath A , L. Elliott A and M. Pitkin ABeach Energy.
The APPEA Journal 52(2) 662-662 https://doi.org/10.1071/AJ11076
Published: 2012
Abstract
Beach Energy has started exploring unconventional gas in the Nappamerri Trough, the central trough within the Cooper Basin, where the Permian section has long been regarded as the primary source for most of the conventional hydrocarbons found within the basin.
This extended abstract discusses the data used to identify the unconventional play and the exploration program carried out to date. Mud weights, drill stem test (DST) pressures and log data from early exploration wells identified the Permian formations as overpressured. This with geochemical and mineralogy analyses indicated that the Roseneath and Murteree Shales had potential similar to successful shale gas plays being developed in the USA.
The quartz and siderite content within both shale sections indicated sufficient brittleness for successful fracture stimulation. In addition, the Nappamerri Trough Permian section showed low permeabilities, which, when combined with overpressure, suggested a basin-centred style play within the Epsilon and Patchawarra sandstones and possibly the Toolachee Formation sandstones.
During 2010–11, Beach drilled two exploration wells sited outside structural closure to test both the shale gas and basin-centred gas system. Both wells have now been fracture stimulated, with very encouraging gas flows from the Roseneath to Patchawarra section. The latest geological data confirms the pre-drill potential for both gas flow from the shales and the presence and production of gas from sandstones outside structural closure, resulting in a significant shale and tight gas resource booking. Ongoing exploration and development will target a potential 300 Tcf gas in place in PEL 218.
Carrie Trembath graduated from the University of Melbourne in 2001 (BSc, hons) and joined Santos as a graduate geologist. After five years working as a development geologist and petrophysicist, she joined Schlumberger as a borehole geologist in Oman. She returned to Australia to work as a petrophysicist at Nexus Energy and Mosaic Oil, before joining Beach Energy in 2010 where she is now working in the unconventional resources team as a geologist and petrophysicist. Member: PESA, FESAus, and SPWLA. |
Lindsay Elliott is a geologist with nearly 40 years in the petroleum exploration industry. He has worked for Esso, CSR, AGL, Santos, and is now at Beach after a short period of consulting. During his career, he has worked on most Australian basins and many overseas. He is now undertaking new venture evaluations for Beach. Member: PESA and AAPG. |
After graduating with a degree in petroleum engineering (UNSW) in 1991, Mark joined Santos as a reservoir engineer. After seven years working on field development of retrograde and tight gas fields, he headed to Japan. He returned to Santos in 2000 prior to joining Origin Energy CSG in 2001 where he was the reservoir development engineer behind the successful Spring Gully CSG field. In 2007, Mark joined Beach Energy, where he is now the co-ordinator of unconventional resources, leading the team that has been exploring and appraising the shale gas play in the Nappamerri Trough. |
References
Alexander, E., 1998—Lithostratigraphy and environments of deposition. In Gravestock, D.I., Hibburt, J.E., and Drexel, J.F. (Eds), The petroleum geology of South Australia, Volume 4: Cooper Basin. Report Book 98/9. Adelaide: Primary Industries and Resources (PIRSA) SA, 69–115.Hillis, R. R., Morton, J. G. G., Warner, D. S., and Penney, R. K. (2001). Deep basin gas: a new exploration paradigm in the Nappamerri Trough, Cooper Basin, South Australia. APPEA Journal 41, 185–200.
