Book contents
- A Concise Guide to Geopressure
- A Concise Guide to Geopressure
- Copyright page
- Contents
- Acknowledgments
- Nomenclature
- 1 Introduction
- 2 Reservoir Pore Pressure
- 3 Mudrock Material Behavior
- 4 The Origins of Geopressure
- 5 Pore Pressure Prediction in Mudrocks
- 6 Pore Pressure Prediction: Unloading, Diagenesis, and Non-Uniaxial Strain
- 7 Pressure and Stress from Seismic Velocity
- 8 Overburden Stress, Least Principal Stress, and Fracture Initiation Pressure
- 9 Trap Integrity
- 10 Flow Focusing and Centroid Prediction
- 11 Flow Focusing, Fluid Expulsion, and the Protected Trap
- References
- Index
3 - Mudrock Material Behavior
Published online by Cambridge University Press: 04 March 2021
- A Concise Guide to Geopressure
- A Concise Guide to Geopressure
- Copyright page
- Contents
- Acknowledgments
- Nomenclature
- 1 Introduction
- 2 Reservoir Pore Pressure
- 3 Mudrock Material Behavior
- 4 The Origins of Geopressure
- 5 Pore Pressure Prediction in Mudrocks
- 6 Pore Pressure Prediction: Unloading, Diagenesis, and Non-Uniaxial Strain
- 7 Pressure and Stress from Seismic Velocity
- 8 Overburden Stress, Least Principal Stress, and Fracture Initiation Pressure
- 9 Trap Integrity
- 10 Flow Focusing and Centroid Prediction
- 11 Flow Focusing, Fluid Expulsion, and the Protected Trap
- References
- Index
Summary
Mudrock is the most abundant material in the uppermost 5 km of the Earth’s crust (Petley, 1999). It has low permeability and undergoes enormous compaction during burial. When mudrock is loaded sufficiently rapidly (e.g., by burial or tectonic loading), the load is borne by both the solid grains (as effective stress) and the pore fluid (as overpressure) because the fluid cannot escape at the rate the loading occurs. The compressibility of the rock defines how much fluid will be expelled, and its permeability defines how rapidly that fluid can be expelled. Because of mudrock’s high compressibility and low permeability, these overpressures can be maintained for geological timescales. Thus, the compaction behavior of mudrocks is one of the most important controls on whether overpressures will form. The degree of compaction is a sensitive indicator of the effective stress. I show in Chapters 5 and 6 how the compaction state is used to interpret the effective stress and ultimately the pore pressure.
- Type
- Chapter
- Information
- A Concise Guide to GeopressureOrigin, Prediction, and Applications, pp. 34 - 63Publisher: Cambridge University PressPrint publication year: 2021