Amrouch, K.

Beaudoin, N.

Bellahsen, N.

Daniel, J.-M.

Lacombe, O.

Adelaide Research &amp; Scholarship

PUBLISHED VERSION  http://hdl.handle.net/2440/87761    Evolution of pore-fluid pressure during folding and basin contraction in overpressured reservoirs assessed by combined fracture analysis and calcite twinning paleopiezometry EGU General Assembly Conference Abstracts, 2014 / vol.16, pp.3552 © Author(s) 2014. CC Attribution 3.0 License.                    PERMISSIONS   http://creativecommons.org/licenses/by/3.0/       Geophysical Research AbstractsVol. 16, EGU2014-3552, 2014EGU General Assembly 2014© Author(s) 2014. CC Attribution 3.0 License.Evolution of pore-fluid pressure during folding and basin contraction inoverpressured reservoirs assessed by combined fracture analysis andcalcite twinning paleopiezometryNicolas Beaudoin (1,2,3), Olivier Lacombe (2,3), Nicolas Bellahsen (2,3), Khalid Amrouch (4), and Jean-MarcDaniel (5)(1) University of Glasgow, School of Geographical and Earth Sciences, Glasgow, United Kingdom(nicolas.beaudoin@glasgow.ac.uk), (2) UPMC Univ Paris 06, UMR 7193, ISTEP, F-75005, Paris, France, (3) CNRS, UMR7193, F-75005, Paris, France, (4) Australian School of Petroleum, Centre for Tectonics, Resources and Exploration (TRaX),University of Adelaide, North Terrace, Adelaide, SA 5005, Australia, (5) Geology Geochemistry Geophysics Direction, IFPEnergies Nouvelles, Rueil-Malmaison, FranceReconstructing the evolution of paleofluid (over)pressure in sedimentary basins during deformation is a chal-lenging problem, especially when no hydrocarbon-bearing fluid inclusions are available to provide barometricconstraints on the fluid system. This contribution reports the application to a natural case (the Bighorn Basin)of recent methodological advance to access fluid (over)pressure level prevailing in strata during sub-seismicfracture development. The fluid pressure evolution in the Mississippian-Permian Madison-Phosphoria carbonatereservoir is tentatively reconstructed from the early Sevier Layer Parallel Shortening to the Laramide folding intwo basement-cored folds: the Sheep Mountain Anticline and the Rattlesnake Mountain Anticline, located on bothedges of the Bighorn Basin. This reconstruction is based on a combination of stress inversion of fault slip data,calcite twins paleopiezometry and rock mechanics.Results point out that supra-hydrostatic pressure values prevail in the carbonate reservoir during most of its wholeSevier-Laramide history, and a coeval evolution between fluid overpressure and differential stress build-up isalso emphasized. In each fold, a maximum value of 30-35 MPa for overpressure (i.e. above hydrostatic value) isrecorded, just before Laramide folding, while minimum values of 0 MPa or 7 MPa are recorded during Sevierforeland flexure/forebulge and Laramide folding, respectively. After normalization to the same depth for bothfolds of differential stress magnitudes obtained from calcite twins paleopiezometry, the reconstructed values forthe two folds can be compared and this comparison provides an image of the evolution fluid pressure levels atthe basin scale. Until folding, the evolution of the fluid overpressure during deformation can be interpreted asreflecting large-scale fluid migrations in a laterally connected reservoir. The drop of fluid overpressure recorded inboth folds during folding illustrates the enhancement of vertical hydraulic permeability that affect the strata duringthe curvature-related fracture development.Another result of our approach is the possible estimate of syn-folding exhumation of strata. The inferredexhumation values range from 0,6 km to 1,3 km at Sheep Mountain and from 0,8 km to 2,0 km at RattlesnakeMountain. These values are consistent with fold growth models predicting exhumation rates ranging from 0.03 to0.40 mm/yr and with published exhumation rates from fission track studies in other Laramide uplifts.This case study illustrates how the combination of stress inversion of fault-slip and calcite twin data with rockmechanics can be used to discuss which are the natural factors that control the pressure evolution in a carbonatereservoir during its large-scale deformation in an orogenic foreland.

Evolution of pore-fluid pressure during folding and basin contraction in overpressured reservoirs assessed by combined fracture analysis and calcite twinning paleopiezometry

https://digital.library.adelaide.edu.au/dspace/bitstream/2440/87761/2/hdl_87761.pdf

Evolution of pore-fluid pressure during folding and basin contraction in overpressured reservoirs assessed by combined fracture analysis and calcite twinning paleopiezometry

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Adelaide Research & Scholarship

Evolution of pore-fluid pressure during folding and basin contraction in overpressured reservoirs assessed by combined fracture analysis and calcite twinning paleopiezometry

Abstract

Similar works

Full text

Available Versions

Adelaide Research &amp; Scholarship

Adelaide Research & Scholarship