Chapter 01 - Geomodeling

3D Geological Modeling

Chapter 01 - Geomodeling

Geomodeling Geological models are created for many dierent purposes, but common to all of them is a desire to build a representation of the subsurface. Geological models may be used to achiee accurate olume calculations or to test the eect of dierent depositional regimes against .obsered data

Fig.1.1: Geologic Geologic Modeling sho!ing the main "eismic "e#uences and ma$or %aults. %aults.

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Fig.1.2: &ntegrated Geocellular !ith "eismic 'ines.

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Fig.1.3: 3D )orosity Modeling.

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3D Grid Concept &n simple terms, a 3D grid diides a model up into bo*es. +ach bo* is called a grid cell and !ill hae a single roc type, one alue of porosity, one alue of !ater saturation, etc. hese are referred to as the cells properties. his is a simpli/cation of the true case, but allo!s us to generate a representation of reality that can be used in calculations, .etc

Fig.1.4: 3D Grid

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Fig.1.5: 3D Geobody Modeling !ith "eismic Cross "ection.

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Fig.1.6: 3D Geomodeling !ith 2orions, 4ones and 'ayers in 5ertical 'ayering.

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Grid Resolution he resolution of the grid !ill be a ey decision !hen building the model. 7 high resolution grid 8many cells9 !ill allo! the modeler to create great spatial comple*ity, but !ill result in a model !hich has many cells and may be cumbersome to use !ith each process taing a long time. 7 lo!er resolution grid !ill hae less scope for comple*ity, but !ill be #uic to !or !ith and !ill allo! the user to test many possibilities #uicly. he decision !ill depend on the purpose of the model, the detail and amount of data aailable. here is little point in creating a model !ith higher resolution horiontally or ertically than the data aailable for modeling. &t is often !ise to begin !ith a coarse model, testing the eects of changes and then increase the resolution as parameters become more certain.

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Fig.1.7: 3D Geocellular Model !ith )ro$ection of the )enetrated ;ells

Grid Structure he inclusion or e*clusion of faults is another ey decision in the model building process. ;hen dealing !ith simulation, the faults may be critical as
Fig.1.8: 3D "tructural Modeling !ith main Ma$or and Minor %aults along depth surfaces. =



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Fig.1.: 2otshot of 3D %acies Modeling !ith "eismic Cross "ection.

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Chapter 01 - Geomodeling

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