Flexural extension and top/fault seal failure in the Bonaparte Basin: input form multi-scale deformation models*
L. Langhi A and B. Ciftci ACSIRO.
The APPEA Journal 51(2) 714-714 https://doi.org/10.1071/AJ10094
Published: 2011
Abstract
Overcoming uncertainties associated with top/fault seal effectiveness still represents a critical challenge for conventional hydrocarbon exploration in the Bonaparte Basin. Cainozoic faults’ development/reactivation and dip-linkage processes through top seal have been well-established as primary causes of the development of conduits, leading to fluid flow from reservoirs. Constraining predictions on structural traps integrity and preservation of hydrocarbon column, however, requires further understanding and quantification of the background mechanism behind the Cainozoic structural activity.
In this paper, we use 2D elastic models to evaluate the evolution of the flexural deformation affecting the Bonaparte Basin petroleum system during the Cainozoic development of the Timor foreland basin. Associated stress distribution is quantified using multi-scale deformation modelling and used to predict the locus of deformation and fault distribution within the Cretaceous top seal and Cainozoic limestone.
Modelling results associated with paleogeographic reconstructions and field-scale structural analysis support that the distribution of a flexural extension front triggers the Cainozoic structural activity. At the reservoir-scale, the horizontal extension results in new fault nucleation within the Tertiary limestone and reactivation of older faults bounding the reservoirs. Shear failure and linkage occurs between the initially detached two sets of faults due to the propagation of fault tip damage zones. The spatial relationship between the two sets, the Cainozoic stress tensor and the mechanical anisotropy of the stratigraphic column might significantly impact on such propagation and fault connectivity. The modelling of the perturbed stress field may provide prediction of potential fracture zones in the top seal and risking of traps structural trap integrity.
Laurent is a senior researcher with CSIRO Earth Science and Resource Engineering; he has 10 years’ experience in petroleum geology and exploration geophysics. After obtaining a master of science and a PhD in geology in his native Switzerland, Laurent needed to escape the snow. He worked as a researcher at the University of Western Australia and as an exploration geologist/geophysicist in the oil and gas industry. In 2006, he joined CSIRO focusing on trap integrity prediction, assessment/visualisation of fluids migration and geomechanical modelling. He also works in the fields of seismic attributes analysis and quantitative seismic for conventional hydrocarbon and CCS. |
Bozkurt holds a bachelor of science (1996), master of science (2001) and PhD (2007)—all in geology. He worked for a few years as a field geologist in base-metal exploration and joined Turkiye Petrolleri AO (TPAO) in 2001 where he was involved in various hydrocarbon exploration projects across eastern Mediterranean region. In 2008, he joined CSIRO Earth Science and Resource Engineering as a senior researcher where he currently focuses on reservoir to basin scale structural and fault seal analysis. |
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