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Autochthonous Salt Deformation Integrated with Basin Modeling. Example on a GulfSpan Dip Line. Allochthonous Salt. Present Day. Basement. Autochthonous Salt. 159 MYBP.
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Autochthonous Salt Deformation Integrated with Basin Modeling Example on a GulfSpan Dip Line
Allochthonous Salt Present Day Basement Autochthonous Salt
159 MYBP • The Sediment temperature history is calculated with an energy balance and a heat flux boundary condition at the base of the model and a surface temperature boundary condition • Taking the initial autochthonous salt thickness as the present day thickness results in the top geometry. • Assuming that the autochthonous salt deforms according the principle shown in Figure 3 of the text suggests an initial salt thickness shown in the bottom geometry. • Advance the slide to view a time history of autochthonous salt deformation.
Discussion • Lateral changes in vertical effective stress leads to deformation of autochthonous salt • Sedimentation rate determines the loading history • The distribution of permeable sand has a significant effect on the vertical effective stress • Sediment temperature near the salt is significantly affected by the autochthonous salt history • Source rock maturation is decreased by millions of years when the source rock is above the salt • This development assumes that all the salt deformation occurs in autochthonous salt • The reality is that allochthonous salt plays a large role in basin development • Including allochthonous salt deformation would require a full stress simulation at every time step • Gradients in lateral stress become important at shallow depths • Simulations would require regridding at each time step to account for the mass and momentum transport of allochthonous salt across time lines
