Geomechanical modeling of stresses adjacent to salt bodies: Part 1—Uncoupled models

Luo, Gang; Nikolinakou, M. A.; Flemings, Peter B.; Hudec, Michael R.

doi:10.1306/04111110144

Cited by 46 publications

(23 citation statements)

References 43 publications

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“…For example, Luo et al [] and Nikolinakou et al [] have showed that horizontal stress increases in the minibasins or adjacent to where salt surface is concave. Orientation rotation of principal stresses adjacent to salt bodies has been observed in geological studies [ Davison et al , , ; Dusseault et al , ] and simulated in previous numerical models [ Bachrach et al , ; Luo et al , ; Nikolinakou et al , ; Sanz and Dasari , ]. Our results show orientation rotation of near‐salt principal stresses over depth and across the minibasin.…”

Section: Discussionmentioning

confidence: 99%

“…These uncoupled models can be divided into two types of models: small‐deformation and large‐deformation models. The small‐deformation uncoupled models are used to illuminate present‐day stress field and stress perturbations near salt bodies due to salt viscoelastic stress relaxation [e.g., Fredrich et al , ; Luo et al , ; Sanz and Dasari , ]. The large‐deformation uncoupled models, by applying viscous or viscoplastic constitutive relation, are used to simulate geological timescale motions and evolutions of salt bodies and sediments and to investigate driving forces in salt basins [e.g., Albertz and Beaumont , ; Albertz et al , ; Daudré and Cloetingh , ; Dirkzwager and Dooley , ; Gemmer et al , , ; Gil and Jurado , ; Ings and Beaumont , ; Poliakov et al , ].…”

Section: Introductionmentioning

confidence: 99%

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Deformation, stress, and pore pressure in an evolving suprasalt basin

et al. 2017

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We develop a two‐dimensional plane strain large‐deformation coupled poroelastoplastic finite element model to simulate initiation and rise of a salt wall from a flat salt body during sedimentation. We run transient analyses with high‐permeability and low‐permeability sediments in the model to simulate drained conditions and overpressure (or pore fluid overpressure). We investigate deformation, stress, and overpressure in the evolving suprasalt basin. Model results show that horizontal stress increases even higher than vertical stress at the flank of the salt wall and in the minibasin due to horizontal pushing out of the rising salt wall and that orientations of principal stresses rotate in the minibasin relative to far‐field stress state. Model predicts that compared with far‐field overpressure, the overpressure near the salt wall and within the minibasin is largely perturbed by the salt body. We find that perturbations of pore pressure (or pore fluid pressure) near the salt wall and within the minibasin cannot be resolved by traditional pore pressure prediction methods such as normal compaction trend approach and mean stress model approach. In order to predict pore pressure more accurately, especially in the regions near salt bodies or where stresses are perturbed, we need to apply a method that includes both effects of mean effective stress and deviatoric stress on pore pressure and compaction, for example, the Modified Cam Clay model approach, to pore pressure prediction. Our results provide geoscientists insights into evolution of salt basins, near‐salt deformation, stress, overpressure, and overpressure prediction methods and have implications for near‐salt wellbore drilling programs.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Deformation, stress, and pore pressure in an evolving suprasalt basin

et al. 2017

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“…Geomechanical modelling can be employed in conjunction with advanced constitutive models to simulate sediment rheology which are capable of accounting for the full 3D stress tensor and its impact on compaction (Albertz and Lingrey, 2012;Albertz and Sanz, 2012;Luo et al, 2012;Smart et al, 2012) and overpressure generation Thornton and Crook, 2014).…”

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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“…Similar models have been used previously to evaluate deformation in gravity-driven settings (e.g. Kjeldstad et al, 2003;Maghous et al, 2014), thrust faults and basins located near salt diapirs (Albertz and Lingrey, 2012;Luo et al, 2012;Smart et al, 2012), and also to model overpressure generation in complex stress regimes Thornton and Crook, 2014). An important aspect of these papers was to incorporate advanced constitutive models that are capable of accurately describing the material rheology in a 3D simulation of an evolving basin.…”

Section: Introductionmentioning

confidence: 99%

Stress and pore pressure histories in complex tectonic settings predicted with coupled geomechanical-fluid flow models

Obradors-Prats

Rouainia

Aplin

et al. 2016

Marine and Petroleum Geology

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. (2016) 'Stress and pore pressure histories in complex tectonic settings predicted with coupled geomechanical-uid ow models.', Marine and petroleum geology., 76 . pp. 464-477. Further information on publisher's website: 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. AbstractMost of the methods currently used for pore pressure prediction in sedimentary basins assume one-dimensional compaction based on relationships between vertical effective stress and porosity. These methods may be inaccurate in complex tectonic regimes where stress tensors are variable. Modelling approaches for compaction adopted within the geotechnical field account for both the full three-dimensional stress tensor and the stress history. In this paper a coupled geomechanical-fluid flow model is used, along with an advanced version of the Cam-Clay constitutive model, to investigate stress, pore pressure and porosity in a Gulf of Mexico style mini-basin bounded by salt subjected to lateral deformation. The modelled structure consists of two depocentres separated by a salt diapir. 20% of horizontal shortening synchronous to basin sedimentation is im-posed. An additional model accounting solely for the overpressure generated due to 1D disequilibrium compaction is also defined. The predicted deformation regime in the two depocentres of the mini-basin is one of tectonic lateral compression, in which the horizontal effective stress is higher than the vertical effective stress. In contrast, sediments above the central salt diapir show lateral extension and tectonic vertical compaction due to the rise of the diapir. Compared to the 1D model, the horizontal shortening in the mini-basin increases the predicted present-day overpressure by 50%, from 20 MPa to 30 MPa. The porosities predicted by the mini-basin models are used to perform 1D, porosity-based pore pressure predictions. The 1D method underestimated overpressure by up to 6 MPa at 3400 m depth (26% of the total overpressure) in the well located at the basin depocentre and up to 3 MPa at 1900 m depth (34% of the total overpressure) in the well located above the salt diapir. The results show how 2D/3D methods are required to accurately predict overpressure in regions in which tectonic stresses are important.

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Geomechanical modeling of stresses adjacent to salt bodies: Part 1—Uncoupled models

Cited by 46 publications

References 43 publications

Deformation, stress, and pore pressure in an evolving suprasalt basin

Deformation, stress, and pore pressure in an evolving suprasalt basin

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

Stress and pore pressure histories in complex tectonic settings predicted with coupled geomechanical-fluid flow models

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