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| Subsidence Related to Fluid Energy Production Home |
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Introduction
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Figure 1. Possible effects of petroleum production. Prolonged or rapid production of oil, gas, and formation water (2) causes subsurface formation pressures to decline (3). The lowered pressures (3) increase the effective stress of the overburden (4), which causes compaction of the reservoir rocks and may cause formerly active faults (1) to be reactivated (5). Either compaction of the strata or downward displacement along faults can cause land-surface subsidence (6). Where subsidence and fault reactivation occur in wetland areas, the wetlands typically are submerged and changed to open water (7). Figure is not to scale. D, down; U, up.
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The Gulf Coast Basin is a region where subsidence and fault activation are common around large, mature oil and gas fields even though moderately deep hydrocarbon production has generally been disregarded as the primary cause.
This project will test the hypothesis that long-term, large-volume oil and gas production in the Gulf Coast Basin has resulted in land-surface subsidence and activation of deep-seated faults around some fields. The project will:
- Investigate the magnitudes of environmental impacts;
- Estimate rates of deformation;
- Identify reservoir parameters that are indicators of subsidence potential; and
- Evaluate geophysical methods for regional subsidence detection and monitoring.
Other tasks will be to:
- Investigate the mechanisms and timing of subsidence;
- Determine if the processes are still active;
- Examine the environmental changes such as reductions in land elevations and elimination or replacement of plant communities;
- Develop conceptual and empirical models to predict subsidence impacts on the basis of production histories and regional geologic framework.
The results of these investigations will provide a basis for designing marsh and barrier-island restoration projects, planning hurricane levees, and managing oil and gas production.
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Presentations:
Trends and Causes of Historical Wetland Loss, Sabine National Wildlife Refuge, Southwest Louisiana (4 MB PDF)
Subsidence, Wetland Loss, and Hydrocarbon Production in the Mississippi Delta Plain
Recent Reductions of Subsidence Rates in the Mississippi River Delta Plain
Poster:
Recent Reduction of Subsidence Rates in the Mississippi River Delta Plain
Printable Poster (17.8 MB PDF)
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Printable Fact Sheet: |
Wetland Subsidence, Fault Reactivation, and Hydrocarbon Production in the U.S. Gulf Coast Region
Printable Fact Sheet
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U.S. Department of the Interior |
U.S. Geological Survey
