Geomechanics and Geology

Geomechanical characterization of mud volcanoes using P-wave velocity datasets
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Published:January 01, 2017
Abstract:
Mud volcanoes occur in many petroliferous basins and are associated with significant drilling hazards. To illustrate the type of information that can be extracted from limited petrophysical datasets in such geomechanically complex settings, we use P-wave velocity data to calculate the mechanical properties and stresses on a two-dimensional vertical section across a mud volcano in the Azeri-Chirag-Guneshly field, South Caspian Basin. We find that: (1) the values of the properties and stresses calculated in this way have realistic magnitudes; (2) the calculated pore fluid pressures show spatial variations around the mud volcano that potentially highlight areas of fluid recharging after the most recent eruption; and (3) the information obtained is sufficient to provide helpful indications of the width of the drilling window. Although calculations of this kind may be readily improved with more sophisticated petrophysical datasets, the simplicity of this approach makes it attractive for reconnaissance surveys designed to identify targets worthy of further investigation in developing our understanding of mud volcano geomechanics, or which could be used to help formulate drilling strategies.
Correction notice: The original version was incorrect. All instances of mbsf (metres below seafloor) should have read mbsl (metres below sea-level).
- acoustical waves
- Azerbaijan
- body waves
- brittleness
- Caspian Basin
- Commonwealth of Independent States
- correlation
- drilling
- durability
- elastic properties
- elastic waves
- equations
- eruptions
- Europe
- feasibility studies
- fluid flow
- fluid pressure
- geophysical methods
- geophysical profiles
- ground water
- mechanical properties
- mud volcanoes
- overpressure
- P-waves
- physical properties
- pore pressure
- porosity
- recharge
- rock mechanics
- seismic methods
- seismic profiles
- seismic waves
- site exploration
- spatial variations
- strength
- stress
- two-dimensional models
- velocity
- waveforms
- Azeri-Chirag-Guneshly Field