Page 316 - Air and Gas Drilling Manual

Chapter 7: Reverse Circulation Models 7-25
roughness of commercial pipe. For conventional drill strings, the openhole surfaces
of boreholes can be approximated with an absolute roughness, e oh = 0.01 ft (i.e., this
example value is the same as concrete pipe which approximates borehole surfaces in
limestone and dolomite sedimentary rocks, or in similar competent igneous and
metamorphic rocks, see Table 8-1).
Equation 7-76 together with Equations 7-77 through 7-80 can be used in
sequential trial and error integration steps starting at the bottom of the annulus (with
the known pressure at the bottom of the annulus) and continuing for each subsequent
change in annulus cross-sectional area until the injection pressure is determined.
References
1. Daugherty, R. L., Franzini, J. B., and Finnemore, E. J., Fluid Mechanics with
Engineering Applications, Eighth Edition, McGraw-Hill, 1985.
2. Brown, K. E., and Beggs, H. D., The Technology of Artificial Lift Methods,
Vol. 1, PennWell Books, 1977.
3. Brown, K. E., et al, The Technology of Artificial Lift Methods, Vol. 2a,
PennWell Books, 1980.
4. Personal communications with Stefan Miska, Department of Petroleum
Engineering, University of Tulsa, January 1999.
5. Lapedes, D. H., McGraw-Hill Encyclopedia of the Geological Sciences, McGraw-
Hill, 1978.

6. Gatlin, C., Petroleum Engineering: Drilling and Well Completions, Prentice-
Hall, 1960.
7. Bourgoyne, A. T., Millheim, K. K., Chenevert, M. E., and Young, F. S.,
Applied Drilling Engineering, SPE, First Printing, 1986.
8. Guo, B., Hareland, G., and Rajtar, J., “Computer Simulation Predicts
Unfavorable Mud Rate and Optimum Air Injection Rate for Aerated Mud
Drilling,” SPE Paper 26892, Presented at the SPE Eastern Regional Conference
and Exhibition, Pittsburgh, Pennsylvania, November 2-4, 1993.