Page 124 - Petroleum and Gas Field Processing

K is a function of T, P, and the composition of a given system. The K
values most widely used are those developed by the National Gas
Processors Association (NGPA) and are presented in Appendix A.
Because the K values are designated for a specific convergence pressure
(defined as the pressure at a given T, where the values of K for all
component in a system become or tend to become equal to unity), it
is important that the value of the operating pressure of the system
should be below the convergence pressure used in predicting the K values.

3.9.4 Some Important Applications for the Flash Equation

In addition to the above, other applications for the flash equation are as
follows:
1. To find the number of stages needed for a given separation: This
simply utilizes the stage-to-stage concept in which another stage
is added to each trial. Convergence is established when the liquid
composition leaving the last stage equals the specified crude oil.
2. To determine the optimum pressure for the second stage: This
involves a trial and error procedure [3].

REFERENCES

1. Bradley, H. B., Petroleum Engineering Handbook, Society of Petroleum
Engineers, Richardson, TX, 1987.
2. Maddox, R. N., Erbar, J. H., and A. Shariat, PDS Ducumentation, CPC, Inc.,
Stillwater, OK, 1976.
3. Abdel-Aal, H. K., Surface Petroleum Operations, Saudi Publishing &
Distributing House, Jeddah, 1998.
4. Arnold, K. and Stewart, M., Design of Oil Handling Systems and Facilities,
Gulf Publishing Company, Houston, TX, Vol. I, 1989.
5. Vonday, D., Spherical process vessels, Oil Gas J., 121–122, April 8, 1957.
6. Chilingarian, G. V., Robertson, J. O. Jr., and Kumar, S., Surface Operations in
Petroleum Production, I, Elsevier Science, Amsterdam, 1987.
7. Whinery, K. F. and Campbell, J. M. A method for determining optimum
second stage pressure in 3-stage separation, J. of Petrol. Technol. 4, 53–54,
1958.
8. Szilas, A. P., Production and Transportation of Oil and Gas, Elsevier Science,
Amsterdam, 1975.
9. Holland, C. D., Fundamentals of Multi component Distillation, McGraw–Hill,
New York, 1981.

Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved.