DETERMINE TOP OF OVERPRESSURE AND STRESS REGIME BY USING CATGEOKU SOFTWARE

Before using these tools, there are several things that must be understood:

1. Normal Shale Porosity data can be obtained from uncompacted sonic logs, laboratory data, or literature data.

2. Biot's Coefficient data can be obtained from laboratory data or literature data.

3. ΔP is the difference between Pore Pressure and Hydrostatic Pressure values

4. Bulk Density data can be obtained from RHOB logs, but must first be converted to kg/m³.

5. Shale porosity data can be obtained from DT logs.

6. Data for validating overpressure can be obtained from MDT or DST.

7. Shmin data can be obtained from Mini-frac/leak-off tests (LOT, MDT, RFT) or borehole breakouts.

8. Shmax data is obtained by using geomechanical data and rock properties.

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DETERMINE TOP OF OVERPRESSURE AND STRESS REGIME BY USING CATGEOKU SOFTWARE

Φo, Normal Shale Porosity (%):

α, Biot's Coefficient:

ΔP threshold for Top Overpressure (Psi):

Copy-paste from Excel (TVD (m), Bulk Density (kg/m³), Shale Porosity (%)):

Copy-paste for Shmin and Shmax from Excel (TVD (m), Shmin (Psi), Shmax (Psi)):

Data Validation (TVD (m), Pressure (Psi)):

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Refference:
Zhang, Jon. (2013). Effective stress, porosity, velocity and abnormal pore pressure prediction accounting for compaction disequilibrium and unloading. Marine and Petroleum Geology. 45. 1-15.
Markou, Nikolaos & Papanastasiou, Panos. (2018). Petroleum geomechanics modelling in the Eastern Mediterranean basin: Analysis and application of fault stress mechanics. Oil & Gas Science and Technology. 73. 57.