We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
A Diagenesis Model for Geomechanical Simulations: Formulation and Implications for Pore Pressure and Development of Geological Structures.
- Authors
Obradors‐Prats, J.; Rouainia, M.; Aplin, A. C.; Crook, A. J. L.
- Abstract
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. Key Points: A novel modeling framework is proposed to investigate the macroscopic effects of diagenesis on porosity loss and geomechanical propertiesThe ductile/brittle transition behavior observed in Kimmeridge clay samples is successfully captured by the new modelThe likely impact of diagenesis in overpressure and structural style is demonstrated
- Subjects
POROSITY; SEDIMENTS; PERMEABILITY; GEOLOGICAL strains &; stresses; FLUID mechanics
- Publication
Journal of Geophysical Research. Solid Earth, 2019, Vol 124, Issue 5, p4452
- ISSN
2169-9313
- Publication type
Article
- DOI
10.1029/2018JB016673