SUPERVISED AUTOMATIC FAULT MODELING FROM AUTOPICKED HORIZONS

Isabelle Duvinage and Richard Cognot and Jean-Laurent Mallet. ( 1997 )
in: 15th gOcad Meeting, ASGA

Abstract

In order to map faults from autopicked horizons, a multi step approach has been developped. In this approach the user has the capability to edit the result and add some modifications. The different steps are (see figure 1): • Cleaning the horizon pointset: The horizon pointsets are autopicked from seismic data. There may be sorne holes due to missing data, especially on fault borders. There may also be some points between two fault blocks or some digitations on the fault borders (see figure 2). A preprocessing tool allows these holes to be filled without filling fault gaps, and removes noisy information (see figure 3). • Extracting fault block boundaries: Instead of looking directly for faults, we will first extract the fault blocks boundaries from the cleaned horizon pointset (see figure 8). The fault block boundaries are first extracted as pointsets (see figure 9). These points are then connected in order to build lines (see figure 10). Using the GOCAD facilities, the user will be able to edit these lines in order to change anything he/she would consider wrong or add personal information. • Defining fault extremities and intersections: On the fault block boundary lines, sorne particular points can be defined, such as extremities and intersections. These specified points separate lines into parts that belong to different faults (see figure 11). • Smoothing the fault parts: By specifying fault extremities and intersections, fault part line segments can be smoothed independently using DSI (Discrete Smooth Interpolation). As aresult, we do not smooth block corners (see figure 12). • Correlating fault parts from one horizon to the other one: We now have to gather the fault parts that belong to a same fault (see figure 13). The set of fault parts that belong to a same fault build a frame for the fault and will be used to build the fault surface (see figure 14). • Building fault surfaces: With each set of fault line parts that belong to a same fault, a fault surface can be built (see figure 15). . . • Building horizon surfaces: Using the fault block boundary lines, and the horizon point set, the horizon surfaces can be built while respecting the fault holes (see figure 16). • Building the 3D model: Finally, using the fault surfaces and the horizon surfaces, a 3D model can be built.

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    BibTeX Reference

    @inproceedings{DuvinageRM1997a,
 abstract = { In order to map faults from autopicked horizons, a multi step approach has been developped. In this approach the user has the capability to edit the result and add some modifications. The different steps are (see figure 1): • Cleaning the horizon pointset: The horizon pointsets are autopicked from seismic data. There may be sorne holes due to missing data, especially on fault borders. There may also be some points between two fault blocks or some digitations on the fault borders (see figure 2). A preprocessing tool allows these holes to be filled without filling fault gaps, and removes noisy information (see figure 3). • Extracting fault block boundaries: Instead of looking directly for faults, we will first extract the fault blocks boundaries from the cleaned horizon pointset (see figure 8). The fault block boundaries are first extracted as pointsets (see figure 9). These points are then connected in order to build lines (see figure 10). Using the GOCAD facilities, the user will be able to edit these lines in order to change anything he/she would consider wrong or add personal information. • Defining fault extremities and intersections: On the fault block boundary lines, sorne particular points can be defined, such as extremities and intersections. These specified points separate lines into parts that belong to different faults (see figure 11). • Smoothing the fault parts: By specifying fault extremities and intersections, fault part line segments can be smoothed independently using DSI (Discrete Smooth Interpolation). As aresult, we do not smooth block corners (see figure 12). • Correlating fault parts from one horizon to the other one: We now have to gather the fault parts that belong to a same fault (see figure 13). The set of fault parts that belong to a same fault build a frame for the fault and will be used to build the fault surface (see figure 14). • Building fault surfaces: With each set of fault line parts that belong to a same fault, a fault surface can be built (see figure 15). . . • Building horizon surfaces: Using the fault block boundary lines, and the horizon point set, the horizon surfaces can be built while respecting the fault holes (see figure 16). • Building the 3D model: Finally, using the fault surfaces and the horizon surfaces, a 3D model can be built. },
 author = { Duvinage, Isabelle AND Cognot, Richard AND Mallet, Jean-Laurent },
 booktitle = { 15th gOcad Meeting },
 month = { "june" },
 publisher = { ASGA },
 title = { SUPERVISED AUTOMATIC FAULT MODELING FROM AUTOPICKED HORIZONS },
 year = { 1997 }
}