Overview

Structural Modeling

StructureSolver lets you create balanced forward models of the hangingwall structures associated with movement on faults.

You can interactively change the models until you have matched the observed structures in your seismic or geologic section.

Through this process you create value by:

  • Constraining fault shapes and cross-fault correlations
  • Clarifying structural kinematics and the interplay between faulting and sedimentation.
What is unique about StructureSolver structural modeling?
  • You can simply create a structural model based on any fault in your Interpretation.
  • StructureSolver rigorously incorporates scientific principles to model the folding that takes place in the hangingwalls of growth faults.
  • StructureSolver seamlessly integrates structural growth and sedimentation so you can model both extensional and contractional growth structures
  • You can simply control all principal variables while continuously overlaying the resulting model over a seismic or geological cross section.
  • This multi-variable interactivity helps you to quickly gain insights into the structures you are modeling.

Watch Mississippi Canyon modeling example

Mississippi Canyon Structural Model

Video

How do I create a structural model?
  • You simply choose to add structural surfaces to any fault in your interpretation.  
  • StructureSolver will automatically configure the set of kink axes that control the deformation within the hangingwall of the fault, and will let you add undeformed structural surfaces using mouse movements and clicks.  
  • You can subsequently deform the shapes of the surfaces you have added by modifying your structural model.
How do I modify a structural model?
 
You perform any of the following operations in arbitrary order and the structural model changes in real time:
  • Add new surfaces to an already partially constructed and deformed structural model
  • Delete or redefine structural surfaces.
  • Modify the shape of the controlling fault using any interpretation function.
  • Manipulate structural surfaces using the functions Stretch Overlying Layers, Move Underlying Layers and Move Individual Surface
  • Change the deformation shear angle in real time
  • Lock or unlock hangingwall cutoffs.
You can also identify structural surfaces, animate the development of a structural model, and show the displacement field in a structural model.
 
You can delete the structural model associated with a fault entirely.
 
You can instantly undo or redo nearly all structural modeling operations.
 
What is the best way to use StructureSolver to model a geological structure?

 You will typically use StructureSolver to model actual structures that are visible on an image of a seismic or geologic section.

The flexibility with which you can create and modify models creates many different opportunities for creative use.

If footwall and hangingwall strata are well-defined in both geometry and correlation, you can use StructureSolver to refine the fault shape.  

  • Interpret a first estimate of the fault geometry.
  • Add structural surfaces and set the footwall reference levels to their observed levels.
  • Move the hangingwall reference points so that the hangingwall reference levels are matched, or alternatively so that the hangingwall cutoffs are matched.
  • If you are confident of the hangingwall cutoffs you may wish to lock them at this stage.
  • Refine the fault shape until the entire hangingwall geometry is matched.
  • The overall hangingwall fold dimension will constrain the dip on the deepest parts of the fault.
  • Details of normal and reverse "drag" near the fault will constrain details of minor convex and concave bends in the fault.

If the fault and hangingwall geometries are well constrained, you can use StructureSolver to define the correlations across the fault.

  • Interpret the fault
  • Add structural surfaces at the hangingwall reference levels.
  • Adjust the footwall reference levels until the hangingwall rollover geometry and cutoffs are matched.
StructureSolver modeling treats one fault at a time - isn't this a serious limitation?

StructureSolver can be very effective at analyzing systems of faults.  You should start by modeling the gross geometry of each major fault.  This helps you understand the overall kinematic picture and the interaction of faults in time and space.

StructureSolver modeling also often does a good job of approximating the displacement patterns of synthetic and antithetic faulting in the hangingwalls of large faults.  Thus while you a modeling a single large fault you can gain important insights into the formation of the minor faults within its hangingwall.

Watch a Rhone Delta Fault System modeling example

Rhone Delta Structural Model

Video

What about thrust faults and inversion structures?

StructureSolver can handle contractional growth structures fairly well.  The geometry of the kink axes does not conform to flexural slip deformation however.  A fairly steep (nearly 90 degree) shear angle gives a good overall approximation for contractional growth structures. Future versions of StructureSolver may incorporate more sophisticated definitions of contractional deformation axes.

Watch Lost Hills contractional growth structure modeling example

Lost Hills Contractional Growth Structure

Video

 

 

Watch a model of an inversion structure

Inversion Model

Video