PEH Volume I Chapter 8: Phase Diagrams

Phase Diagrams:
     Critical Temperature: max T two phases exist (higher T only vapor).
     Critical Pressure: max P two phases exist (higher P only liquid).

Surfactant/Polymer Flood: oil/water soluble mix reduces interfacial tension oil/H2O interface.
Gas-Injection: miscible displacement eliminates oil/displacing phase interface capillary forces.

Phase Rule: component number determines max number of phases coexisting at fixed T, psi.

Phase Diagrams: Plait Point: where bi nodal curve liquid & vapor portions meet and compositions are identical.. 
          Binary: Vapor/liquid; fixed T; pressure-composition (p-x-y) 2 components (I-373-375). 
          Ternary: 3 components; each component equilateral triangle. (I-376-381). 
               …composition expressed in volume, mass, or mole fraction; 100% on each corner. 
               …line parallel to a side is a constant fraction of the opposite corner component.
               …perpendicular lines from any composition point to each side (LT) sums to any side.
               …two phase regions fall on the triangle sides. 
          Quaternary: 4 components; tetrahedral diagram, faces are ternary phase diagrams.

Reservoir Fluid Systems: See Guidebook 13 RES 10

Much of this material is being added to the Guidebook; in the meantime, feel free to pencil it in.

Note that ternary diagrams are a rich target for questions; read section 8.5 carefully. Understand how the ternary diagram is used, and underline the key passages relating my notes above. Often, what makes sense physically isn't so clear when put into words, and vice-versa.

Be warned: I've observed each person will have their own weak areas on this subject; your needed focus may be different than mine or others. So skim all the material and underline key passages (in pencil: in a year the subject may seem bloody obvious so leave the option to erase half of it later to keep your focus on weak areas).