Consortium Overview
The Penn State GeoFluidsIII Consortium will study the state and evolution of pressure, stress, and fluid migration in 1) the sub-salt environment, 2) shallow water flow regimes, and 3) thrust belts. We will couple characterization of pressure, stress, rock properties, and geology with theoretical modeling to describe the state and evolution of rock and fluid properties. Practical results will include: 1) development of workflows and techniques for pressure/stress prediction in the sub-salt, thrust belts, and the shallow water flow regime; 2) algorithyms to couple deformation, stress, pressure and flow to be used in basin flow models; 3) on-line software to demonstrate consortium results.
Why Complex Stress Regimes? Pressure prediction techniques and basin modeling generally assume that all deformation is uniaxial, which allows stress and pressure to be predicted from a vertical effective stress-porosity relationship. In new provinces that are of central interest to the petroleum industry, deformation is not uniaxial and stress and pressure are coupled in more complex ways than previously assumed. In thrust belts, the lateral stress is greater than the vertical stress and sediment that was originally buried in a basin under uniaxial strain conditions is later deformed in plane strain. In the sub-salt regime, the interaction of isostatically stressed salt with sediment that can bear differential stresses results in complex stress response near the salt-sediment interface—a zone of critical interest to industry. In shallow water flow systems, the coupling of pressure and stress near the sea floor drives both slope instability and shallow water flow. To understand and ultimately predict pressures, stresses, and rock properties in these regimes, a new level of understanding, modeling, and analysis must be applied.
Field Studies: Our work will be founded upon detailed field studies. We will study the shallow water flow system in the Mars-Ursa minibasin. Shell and its partners released an extraordinary data set across the shallow section. In the Sub-Salt, discussions are underway to study the Mahogany Field (Anadarko) and the Conger Field (Amerada Hess). We will study the Nankai Accretionary Prism as our primary fold-thrust belt location. Consortium partners may offer an additional fold-thrust belt location for study.
What’s Fundamental? Our work will lay the groundwork for a new generation of basin modeling algorithyms and pressure/stress prediction techniques. This new generation will go beyond the restrictive assumption that deformation is uniaxial. Instead, we will couple reasonable assumptions about far field stress state with rheological models to predict stress and pressure. For example, in thrust belts we will couple long-standing stress models with a soil model (that describes porosity change to both changes in mean stress and differential stress) to predict pressure within and below thrust belts. In a similar fashion, in the sub-salt setting we will study how the interaction between salt (which can bear little differential stress) with bounding sediments (which can bear significant differential stress) results in variation of pressure and stress at the salt sediment interface. Finally, in shallow water flow systems, we have a unique opportunity to constrain basic rock and fluid properties (permeability, compressibility), which will provide critical information on how overpressures are generated in the very shallow sedimentary section.
What’s Practical? We will extract and transfer practical applications
and technology from this research. We will develop techniques and workflows
to:
1) Predict pressure and stress in thrust belts
2) Estimate the vertical
and least principal stresses beneath the salt
3) Estimate locations of
shallow water flow from limited seismic and well control.
Ongoing Consortium Research: The above primary goals will complement ongoing efforts in the following. A) Piezoprobe Tool Development and Analysis wherein we will design, build and analyze results from a pore pressure penetrometer. B) Deformation Experiments on whole core with focus on low permeability mud-rocks to understand in-situ observations of stress, pressure, permeability, and porosity; C) Field Programs-Advocating for an experimental drilling program into the shallow sedimentary section at Mars-Ursa and Brazos-Trinity basins in the Integrated Ocean Drilling Program; D) Hydrate Systems Analysis-characterization and modeling of hydrate systems.
Deliverables: Consortium deliverables include: 1) Annual Meetings; 2) Annual Reports; 3) an On-Line Rock Properties Database; 4) License to Inventions, Patents and Software developed; 5) Company Visits; 6) Final Workbook; 7) Notice of Papers Submitted for Publication; and 8) On-Line Software to demonstrate pressure prediction and modeling approaches.
How Much?
Start Date: September 1, 2004
Duration: 5 years
Cost: $23,000/year