Generating an Interface Model

At this stage, Insight has already run the simulation in the background with a set of default parameters. These parameters can be modified in the Interface Model tab. Re-run the simulation after changing any of the parameters.

The results of the simulation can be exported to disk or viewed on crossplots.

  1. Interface Stochastic Model Parameters:
  • Depths: Enter the depth sequence in TVDBML (True Vertical Depth Below Mud Level). The format is min-max [interval]. A separate simulation is run at each depth in this sequence.
  • Error: Enter the error probability percentage.
  • Near Angle: The incidence angle at the interface to calculate near elastic properties. There is an extra input box for standard deviation (±).
  • Far Angle: The incidence angle at the interface to calculate far elastic properties. There is an extra input box for standard deviation (±).
  • Calculation:
    • SHUEY_TWOTERM: Calculates considerably faster and is only a valid approximation when the far angle is less than 35°.
    • SHUEY_THREETERM: Recommended calculation method in most cases. It calculates a non-linear AVO response, which is especially useful when modelling far angles.
  • Iterations: Enter the desired number of iterations. A higher number of iterations typically yields a better estimate of the model but takes longer to run.
  1. Interface Model PDFs: Select the horizontal and vertical axes of the Probability Density Function (PDF) crossplot charts. To remove any chart, click the Remove Row (x) icon. To add, click the Add (+) icon.
  2. Interfaces: To exclude an interface from the simulation, click their green Show/Hide button, and the button will turn amber. The depth range for each interface can optionally be overridden in the adjacent Min Depth Override and Max Depth Override boxes.

View in Crossplot: Click to open a Crossplot window with the Probability Density Function model already selected. Go to the crossplot's LithoFluid model tab and select the attributes to plot (e.g. AI vs Vp/Vs). In the next table, configure the visible layers or interfaces using the green/amber lights then select the depth(s) to display on the crossplot. The crossplot can display ellipses, their center and individual points. For details, please refer to Using Litho-Fluid Models.

Re-Run Simulations: Click to update the stochastic modelling output after changing any of the interface stochastic modelling parameters. While the simulation is running the "View Log" button turns into a spinner.

View Log/Warnings: Click to view successful generation and warning logs. A warning icon indicates issues the Stochastic Model window has run into and where the problem has arisen, normally relating to over-extrapolation of trends. This means that the stochastic modelling was performed at a depth that is deeper or shallower than where the trends were defined.

Export PDF: Click to export the Probability Density Function to .dupdf format.