1887
1st Australasian Exploration Geoscience Conference – Exploration Innovation Integration
  • ISSN: 2202-0586
  • E-ISSN:

Abstract

The Pelarang Anticline is part of the NNE-SSW oriented Samarinda Anticlinorium, a detached thrust-and-fold belt in the Tertiary Kutai Basin. Results from an airborne gravity gradiometer survey over the Pelarang Anticline are presented herein. The Pelarang Anticline is interpreted as a detachment fold ~30km long with steeply dipping (70°-80°) flanks. However, seismic imaging on existing 2D data is poor.

In October 2016 Cue Energy acquired airborne gravity gradiometer survey data over the anticline. The survey revealed a large (~10mGal) gravity signal range, and that the anticline is associated with a strong, positive gravity anomaly. Subsequent application of potential field enhancement filters clearly delineated the crest and the flanks of the feature.

2D modelling of selected profiles across the anticline suggests that it can be modelled as a 1,500m-2,000m wide, by ~2,000m high shale body that is close to breaching the surface in places. This is in alignment with an interpretation that the feature is cored by high-pressure shales, resulting in un-prospective areas.

However, 3D modelling has revealed significant along-strike variations in the depths to the crest of the anticline, suggesting the presence of several anomalous structural lows. Further investigation suggests these features are pull-apart mini-grabens, formed in response to localized shear movements. At least two commercial hydrocarbon accumulations, Sambutan and Mutiara, appear to be genetically related to the newly recognized structural anomalies.

This survey has led to the recognition of a new exploration play in the region, and provided a tool to pursue it.

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2018-12-01
2026-01-21
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References

  1. Bachtiar, A., Kumiawan, E., and Purwanti, Y., 1998, Geological data acquisition during 3D seismic operation in Mutiara field area, Kalimantan, Indonesia: Indonesian Petroleum Association, Proceedings of the 26th Annual Convention, p. 85-104.
  2. Biantoro, E., Muritno, B.P., and Mamuaya, J.M.B., 1992, Inversion faults as the major structural control in the northern part of the Kutei Basin, East Kalimantan: Indonesian Petroleum Association, Proceedings of the 21st Annual Convention, p. 45-68.
  3. Blakely, R.J., and Simpson, R.W., 1986, Approximating edges of source bodies from magnetic or gravity anomalies: Geophysics, 51, p. 1494-1498.
  4. Campbell, S.J., Lennane, M., and Pisapia, S.E., 2008, Using gravity data to help identify and differentiate mobile shale bodies, Offshore Sabah: Petroleum Geology Conference and Exhibition 2008, Kuala Lumpur, Malaysia, Extended Abstracts.
  5. Chambers, J.L.C., Carter, I., Cloke, I.R., Craig, J., Moss, S.J., and Paterson, D.W., 2004, Thin-skinned and thick-skinned inversion-related thrusting- A structural model for the Kutai Basin, Kalimantan, Indonesia: in K. R. McClay, ed., Thrust tectonics and hydrocarbon systems: AAPG Memoir 82, p. 614- 634.
  6. Doust, H., and Noble, R.A., 2008, Petroleum systems of Indonesia: Marine and Petroleum Geology, 25, p. 103-129.
  7. Ferguson, A., and McClay, K., 1997, Structural modelling within the Sanga Sanga PSC, Kutai Basin, Kalimantan: its application to paleochannel orientation studies and timing of hydrocarbon entrapment: in Howes, J.V.C., and Noble, R.A., eds., Proceedings of the IPA Petroleum Systems of SE Asia and Australasia conference: Indonesian Petroleum Association. p. 709-726.
  8. Jacques, J.M., Parsons, M.E, Price, A.D., and Schwartz, D.M., 2003, Improving geologic understanding with gravity and magnetic data: Examples from Gabon, Nigeria and the Gulf of Mexico: First Break, 21, p. 57-62.
  9. McClay, K., Dooley, T., Ferguson, A. and Poblet, J., 2000, Tectonic Evolution of the Sanga Sanga Block, Mahakam Delta, Kalimantan, Indonesia: AAPG Bulletin, 84 (6), p. 765-786.
  10. Miller, H. G., and V. Singh, 1994, Potential field tilt - A new concept for location of potential field sources: Journal of Applied Geophysics, 32, p. 213-217.
  11. Murphy, C.A., 2004, The Air-FTG™ airborne gravity gradiometer system: in R.J.L. Lane, editor, Airborne Gravity 2004 - Abstracts from the ASEG-PESA Airborne Gravity 2004 Workshop: Geoscience Australia Record 2004/18, p. 7-14.
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