[OpendTect_Users] Deriving 3D horizon from 2D horizon: big holes

[Julien Moreau]

Hi Randy,

The interpolation is made according to the grid parameter, i.e. from the survey geometry. Unlike most of the 2D horizons, 3D horizons are clipped within the frame of the survey which is a sugarbox. Their coordinates are relative to the survey, not to the real seismic space.
If you don't have any 3D horizons derived from a seismic cube you can try to play with the survey parameters. If you do have a cube, the horizons will be distorted and you will have to pick them again. You can try to dump your 2D line into a temporary survey if you have a mixed dataset.
So:
First all your lines should be within the survey
Secondly, try to have a coarse spacing, meaning your u,v increment of the grid (the Xline-inline increment of the survey) with something quite large (equivalent to 4 times trace spacing?).

You should get some 3D surface. You will be able to tune that to get some meaningful results by optimising your survey geometry.

Best regards,

Julien

Julien Moreau, PhD
Assistant Professor, Applied Geophysics
Department of Geography and Geology, University of Copenhagen,
Øster Voldgade 10, 1350 København, Denmark
Office: +45 353-24168

________________________________
From: users-bounces at opendtect.org [users-bounces at opendtect.org] on behalf of Randy Hunt [rl_hunt at yahoo.com]
Sent: 02 October 2012 21:45
To: users at opendtect.org
Subject: [OpendTect_Users] Deriving 3D horizon from 2D horizon: big holes

Hi everybody, I have been using OpenDtect and appreciate what it can do.   In some areas, it's a little "rough", like when I go to derive a 3D horizon from a 2D one.  No matter what parameters or gridding algorithm I use, I only get values interpolated along the 2D lines, nothing in the gaps between lines.   On another horizon along the exact same lines, I have no such problem.   Has anyone seen this issue, and what can I do to fix it?

Any ideas much appreciated.   Thanks to everybody who has worked to provide such a great open source tool for geophysicists everywhere.

regards

Randall Hunt
Pittsburgh, PA

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