Hydrodynamic flow and pressure transients
Exploring for Oil and Gas Traps | |
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Series | Treatise in Petroleum Geology |
---|---|
Part | Predicting the occurrence of oil and gas traps |
Chapter | Evaluating top and fault seal |
Author | Grant M. Skerlec |
Link | Web page |
Store | AAPG Store |
Pressure gradients and the resulting buoyant pressures are not always static. Both hydrodynamic flow and pressure transients change seal capacity.
Hydrodynamic flow
A hydrodynamic gradient will either increase or decrease the height of a trapped hydrocarbon column.[1][2][3] Flow in the direction of the buoyant vector decreases the seal capacity. Flow opposite the direction of the buoyant vector increases the seal capacity.
The hydrodynamic effect has been demonstrated to be important in trapping hydrocarbons in the Western Canada Basin[2][3]
Pressure transients
Fluid pressure gradients may fluctuate dramatically during faulting and basin evolution.[4] Estimates of trapping capacity based upon the capillary model assume a static pressure gradient or a uniform regional hydrodynamic gradient.
Measurements of fluid inclusions, however, suggest pressure transients along faults of as much as 126 MPa pressure::(1,825 psi).[5] Similar episodic fluid flow events are inferred from sandstone cements in the North Sea.[6]
Leakage through seals and seal capacity may be as episodic as hydrocarbon generation, migration, and pressure transients.
See also
- Seal capacity: pitfalls and limitations of estimation
- Displacement pressure: does the theory predict reality?
- Saturations required for hydrocarbon flow
- Seal capacity of breached and hydrocarbon-wet seals
References
- ↑ Schowalter, T. T., 1979, Mechanics of secondary hydrocarbon migration and entrapment: AAPG Bulletin, vol. 63, no. 5, p. 723–760.
- ↑ 2.0 2.1 Dahlberg, E. C., 1982, Applied Hydrodynamics in Petroleum Exploration: New York, Springer-Verlag, 161 p.
- ↑ 3.0 3.1 Lerche, I. Thomsen, R. O., 1994, Hydrodynamics of Oil and Gas: New York, Plenum Press, 308 p.
- ↑ Sibson, R. H., J. Moore, and A. H. Rankin, 1975, Seismic pumping—a hydrothermal fluid transport mechanism: Journal of the Geological Society of London, vol. 131, p. 653–659., 10., 1144/gsjgs., 131., 6., 0653
- ↑ Parry, W. T., and R. L. Bruhn, 1990, Fluid pressure transients on seismogenic normal faults: Tectonophysics, vol. 179, no. 3–4, p. 335–344., 10., 1016/0040-1951(90)90299-N
- ↑ Robinson, A., J. Gluyas, 1992, Duration of quartz cementation in sandstones, North Sea and Haltenbanken basins: Marine and Petroleum Geology, vol. 9, no. 3, p. 324–327., 10., 1016/0264-8172(92)90081-O