PNG 520
Phase Relations in Reservoir Engineering

Action Item


Answer the following problems, and submit your answers to the drop box in Canvas that has been created for this module.

Please note:

  • Your answers must be submitted in the form of a Microsoft Word document.
  • Include your Penn State Access Account user ID in the name of your file (for example, "module2_abc123.doc").
  • The due date for this assignment will be sent to the class by e-mail in Canvas.
  • Your grade for the assignment will appear in the drop box approximately one week after the due date.
  • You can access the drop box for this module in Canvas by clicking on the Lessons tab, and then locating the drop box on the list that appears.

Problem Set

  1. If a gas is ideal, would its compressibility factor (Z) be always equal to one?

  2. For a gas with Z=1, would its behavior be ideal?

  3. Take a look at the Standing-Katz Compressibility Factor Plot for Natural Gases. What is the information you need to obtain a value of “Z” for a gas? What happens to “Z” at low pressures? What is the behavior of “Z” at high pressures? What is the compressibility factor of Methane (Pc = 666 psia, Tc = – 117 F) at P = 1000 psia and T = 0 F?
  4. As pressure approaches to zero, what should vdW EOS collapse to? Why? Can you show it?
  5. Speculate on how you could calculate the “Z” factor for a gas using vdW EOS.