2D modeling of overpressure in a salt withdrawal basin, Gulf of Mexico, USA

Allwardt, Jeffrey R.; Michael, G. Eric; Shearer, Chuck R.; Heppard, Phil; Ge, Hongxing

doi:10.1016/j.marpetgeo.2009.01.009

Cited by 15 publications

(10 citation statements)

References 12 publications

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“…Forward basin modeling is a widely used technique capable of capturing the evolution of sediment properties through basin histories, providing useful insights into present‐day distributions of stresses, porosity, permeability, pore pressure, and temperature and identifying likely flow pathways which are useful for economic geological applications (e.g., Allwardt et al, ; Bekele et al, ; Flemings & Lupa, ; Kjeldstad et al, ; Neumaier et al, ; Schneider et al, ).…”

Section: Introductionmentioning

confidence: 99%

A Diagenesis Model for Geomechanical Simulations: Formulation and Implications for Pore Pressure and Development of Geological Structures

et al. 2019

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Forward basin modeling is routinely used in many geological applications, with the critical limitation that chemical diagenetic reactions are often neglected or poorly represented. Here, a new, temperature-dependent, kinetic diagenesis model is formulated and implemented within a hydromechanical framework. The model simulates the macroscopic effects of diagenesis on (1) porosity loss, (2) sediment strength, (3) sediment stiffness and compressibility, (4) change in elastic properties, (5) increase in tensile strength due to cementation, and (6) overpressure generation. A brief overview of the main diagenetic reactions relevant to basin modeling is presented and the model calibration procedure is demonstrated using published data for the Kimmeridge Clay Formation. The calibrated model is used to show the implications of diagenesis on prediction of overpressure development and structural deformation. The incorporation of diagenesis in a uniaxial burial model results in an increase in overpressure of up to 9 MPa due to both stress-independent porosity loss and overpressure generated by disequilibrium compaction caused by a reduction in permeability. Finally, a compressional model is used to show that the incorporation of diagenesis within geomechanical models allows the transition from ductile to brittle behavior to be captured due to the increase in strength that results in an overconsolidated stress state. This is illustrated by comparison of the present-day structures predicted by a geomechanical-only model, where a ductile fold forms, and a geomechanical model accounting for diagenesis in which a brittle thrust structure is predicted.

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Section: Introductionmentioning

confidence: 99%

A Diagenesis Model for Geomechanical Simulations: Formulation and Implications for Pore Pressure and Development of Geological Structures

et al. 2019

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“…Because accuracy is crucial, several techniques are commonly used in combination to reduce uncertainty in predictions. Two main approaches are used for pore pressure prediction: (1) porosity-based methods which depend on rock property relationships and the analysis of the trends with depth (Van Ruth et al., 2002;Yang and Aplin, 2004;Bera, 2010;Zhang, 2011) and (2) forward basin modelling (Schneider et al, 1996;Bekele et al, 2001;Schneider and Hay, 2001;Bolås et al, 2004;Allwardt et al, 2009;Hantschel and Kauerauf, 2009;Neumaier et al, 2014), which provides numerical simulations of different physical and chemical mechanisms of overpressure generation and dissipation during basin evolution and therefore is capable of capturing pore pressure history over geologic times. The main limitation of both approaches is that the adopted mechanical compaction models are unidimensional and based on the vertical effective stress.…”

Section: Introductionmentioning

confidence: 99%

Assessing the implications of tectonic compaction on pore pressure using a coupled geomechanical approach

Obradors-Prats

Rouainia

Aplin

et al. 2017

Marine and Petroleum Geology

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Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractOverpressure prediction in tectonic environments is a challenging topic. The available pore pressure prediction methods are designed to work in environments where compaction is mostly one dimensional and driven by the vertical effective stress applied by the overburden. Furthermore, the impact of tectonic deformation on stresses, porosity and overpressure is still poorly understood. We use a novel methodology to capture the true compaction phenomena occurring in an evolving 3D stress regime by integrating a fully-coupled geomechanical approach with a critical state constitutive model. To this end, numerical models consisting of 2D plane strain clay columns are developed to account for compaction and overpressure generation during sedimentation and tectonic activity. We demonstrate that a high deviatoric stress is generated in compressional tectonic basins, resulting in a substantial decrease in porosity with continuing overpressure increase.The overpressure predictions from our numerical models are then compared to those estimated by the equivalent depth method (EDM) in order to quantify the error induced when using classical approaches, based on vertical effective stress, in tectonic environments. The stress paths presented here reveal that a deviation from the uniaxial burial trend can substantially reduce the accuracy of the EDM overpressure predictions.

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“…The prediction of pore pressure in sedimentary basins is often addressed using one-dimensional methods (e.g., Daniel, 2001;Hennig et al, 2002;van Ruth et al, 2002;Zhang, 2013), assuming that mechanical compaction is solely driven by the vertical effective stress exerted by the overburden (Hubbert & Rubey, 1959;Terzaghi, 1923). Even in cases where pore pressure evolution is modeled using basin models which incorporate 2-D or 3-D fluid flow, porosity loss is generally considered as being a simple function of vertical effective Journal of Geophysical Research: Solid Earth 10.1002/2017JB014074 stress (e.g., Allwardt et al, 2009;Flemings & Lupa, 2004). In this way, porosity is a function of vertical effective stress, which then allows pore pressure to be estimated.…”

Section: Introductionmentioning

confidence: 99%

Hydromechanical Modeling of Stress, Pore Pressure, and Porosity Evolution in Fold‐and‐Thrust Belt Systems

et al. 2017

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We present coupled, critical state, geomechanical‐fluid flow simulations of the evolution of a fold‐and‐thrust belt in NW Borneo. Our modeling is the first to include the effects of both syntectonic sedimentation and transient pore pressure on the development of a fold‐and‐thrust belt. The present‐day structure predicted by the model contains the key first‐order structural features observed in the field in terms of thrust fault and anticline architectures. Stress predictions in the sediments show two compressive zones aligned with the shortening direction located at the thrust front and back limb. Between the compressive zones, near to the axial plane of the anticline, the modeled stress field represents an extensional regime. The predicted overpressure distribution is strongly influenced by tectonic compaction, with the maximum values located in the two laterally compressive regions. We compared the results at three notional well locations with their corresponding uniaxial strain models: the 2‐D thrust model predicted porosities which are as much as 7.5% lower at 2.5 km depth and overpressures which are up to 6.4 MPa higher at 3 km depth. These results show that one‐dimensional methods are not sufficient to model the evolution of pore pressure and porosity in contractional settings. Finally, we performed a drained simulation during which pore pressures were kept hydrostatic. The predicted geological structures differ substantially from those of the coupled simulation, with no thrust faulting. These results demonstrate that pore pressure is a key control on structural development.

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2D modeling of overpressure in a salt withdrawal basin, Gulf of Mexico, USA

Cited by 15 publications

References 12 publications

A Diagenesis Model for Geomechanical Simulations: Formulation and Implications for Pore Pressure and Development of Geological Structures

A Diagenesis Model for Geomechanical Simulations: Formulation and Implications for Pore Pressure and Development of Geological Structures

Assessing the implications of tectonic compaction on pore pressure using a coupled geomechanical approach

Hydromechanical Modeling of Stress, Pore Pressure, and Porosity Evolution in Fold‐and‐Thrust Belt Systems

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