How to mark a pinchout/intersection of two surfaces using a polygon?
Investigating stratigraphic traps or a stratigraphic surface which has been interrupted by a fault? How do we map the resultant pinchout/intersection between these two horizons using DUG-Insight? The workflow below discusses how to create a detailed polygon outlining the pinchout/intersection.
- Pick the top (h1) and base (h2) horizons of your pinchout structure
- Create a pinchout horizon using Horizon maths
- Inputs: h1 = top horizon, h2 = base horizon
- Formula: if (h1<h2, h1, nan)
- (If top horizon is greater than base horizon use top horizon. If not use nan as value.)
- Create a constant horizon using the Constant horizon
- Value: 0 ms
- Vertical: TWT
- Output grid: polygon which covers entire horizon area
- Spacing: 100
- Survey: Same 3D survey as original horizons
- Merge the pinchout horizon created in step 2 and constant horizon created in step 3 using Horizon Maths
- Inputs: h1 = pinchout horizon, h2 = constant horizon
- Formula: merge (h1, h2)
- (Merge pinchout horizon and constant horizon, give priority to pinchout horizon)
- Display in Map View.
We now have the intersection represented clearly on the merged horizon. Create a polygon along this boundary using create polygon from contours tool.
- Open Display tab and select contours
- Display 0 contour in Map View
- Create polygon from contour 0 using Create contour Polygons
- Final polygon showing pinchout intersection.