The Model Reference Card
Learning objectives
- Hold the whole course as one deck of flip cards, a model on each
- Read the front for what a model is and when to reach for it
- Flip to the equation, the Ogbon-1 canon anchor, and the section that built it
- Take the course home as a reference you can consult on the job
The Course, Condensed
The Lab wired the models together; this section lays them out. Every model the course built becomes a flip card. The front names it and tells you when to reach for it, the one-line judgment that took a whole section to earn. Flip the card and you get the equation, the Ogbon-1 canon anchor that makes it concrete, and the section that built it, so a half-remembered relation is one tap and one click away from the widget that taught it.
Read the deck as the course remembering itself. Effective stress and the vertical stress from the density integral; the Biot coefficient and the two-thirds stress path of poroelasticity; the Coulomb and Byerlee criteria for failure; Eaton for pore pressure; the frictional limit and the stress polygon; the Kirsch hoop stress and the breakout-width inversion; fracture closure and breakdown; slip tendency and the McGarr bound for faults; Geertsma subsidence and the 4D time-shift for the producing field. Seventeen cards, one per load-bearing idea, each anchored to the same self-consistent Ogbon-1 state, Sv 67.7, Pp 35.3, Shmin 46, SHmax 62, that has threaded every part.
How to Use It
On the job, the deck is a decision aid. Facing a rock or a well, ask which card the situation calls for: a fault whose stability you doubt is a slip-tendency card; a depleting field is a stress-path card; a breakout on an image log is a breakout-width card. The front tells you whether the model fits; the back gives you the equation to run and a number to sanity-check it against. That habit, matching a situation to a model and carrying an anchor to catch a blunder, is the whole discipline of the course in one motion. The next section makes the anchors executable: five Python programs that reproduce every one of these numbers exactly, ready to run and to extend.
References
- Zoback, M. D. (2007). Reservoir Geomechanics. Cambridge University Press.
- Fjaer, E., Holt, R. M., Horsrud, P., Raaen, A. M., & Risnes, R. (2008). Petroleum Related Rock Mechanics (2nd ed.). Elsevier.