Results are presented from an experimental study which demonstrates the feasibility of using an existing galling tester and test method as a screening device for evaluating thread compound additives for galling protection. The galling tester employs tubular pin and box specimen pairs fabricated from steel tubing used in the oil field. For the test thread compounds, four different additive packages were used, all with the same grease base of lithium stearate. For reference purposes, the lithium stearate grease base without any additives was tested as one of the thread compounds. The data obtained on contact stress at galling failure show that of the five thread compounds tested, the best galling protection is afforded by the API Modified thread compound, the industry standard for casing and tubing used by the oil industry. The other four compounds show lower galling failure contact stresses of varying degrees. Friction coefficient data obtained during the tests are also presented and discussed.

Issue Section:
Research Papers
Topics:
Galling, Thread, Tubing, Failure, Lithium, Stress, American Petroleum Institute, Engineering standards, Friction, Oil fields, Steel
1.
American Petroleum Institute, 1972, “API Bulletin on Thread Compounds for Casing, Tubing, and Line Pipe,” Bull 5A2.
2.
American Society for Testing Materials, 1989, “Standard Test Method for Galling Resistance of Materials,” Designation G98–89, Annual Book of ASTM Standards, Vol. 03.02, pp. 381–383.
3.
Carper
H. J.
,
Ku
P. M.
, and
Anderson
E. L.
,
1973
, “
Effect of Some Material and Operating Variables on Scuffing
,”
Mechanism and Machine Theory
, Vol.
8
, No.
2
, pp.
209
–
232
.
4.
Carper
H. J.
, and
Ku
P. M.
,
1975
, “
Thermal and Scuffing Behavior of Disks in Sliding-Rolling Contact
,”
ASLE Trans.
, Vol.
18
, No.
1
, pp.
39
–
47
.
5.
Carper
H. J.
,
Ertas
A.
,
Issa
J.
, and
Cuvalci
O.
,
1992
, “
Effect of Some Material, Manufacturing, and Operating Variables on the Friction Coefficient in OCTG Connections
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
114
, No.
4
, pp.
698
–
705
.
6.
Dixon, W. J., and Massey, F. J., 1957, Introduction to Statistical Analysis, 2nd ed., McGraw-Hill, pp. 318–327.
7.
Ertas
A.
,
Carper
H. J.
,
Cuvalci
O.
,
Ekwaro-Osire
S.
, and
Blackstone
W. R.
,
1992
, “
Experimental Investigation of Galling Resistance in OCTG Connections
,”
ASME Journal of Engineering for Industry
, Vol.
114
, No.
1
, pp.
100
–
104
.
8.
Ertas
A.
,
Carper
H. J.
, and
Blackstone
W. R.
,
1992
, “
Development of a Test Machine and Method for Galling Studies
,”
Journal of Experimental Mechanics
, Vol.
32
, No.
4
, pp.
340
–
347
.
9.
Ertas, A., and Jones, C., 1994, The Engineering Design Process, Wiley, Inc., New York.
10.
Hawke, M. C., 1984, “Predicting Makeup Torque of Threaded Tapered Connections and Evaluation of Coefficients of Friction,” SPE Paper No. 13068.
11.
McDonald, H. B., 1994, Private Communication, Bestolife Corporation, Dallas, TX.
12.
Peterson, M. B., Ives, L. K., and Bhansali, K. J., 1987, “A Literature Review of the Galling Process,” Metal Transfer and Galling in Metallic Systems, H. D. Merchant and K. J. Bhansali, eds., The Metallurgical Society, Inc., pp. 1–25.
13.
Prengaman, R. D., 1981, “Thread Compounds—How Do They Work?,” Pet. Eng. Intl., Oct. 1981.
14.
Prengaman, R. D., 1985, “Making the Right Connection... A Comparison of Zinc and Lead Thread Compounds,” Drilling, June 1985.
15.
Shoukry, M. M., Fakhry, M. A., Farag, M. M., Sun, T. C., and Merchant, H. D., 1987, “Sheet to Tool Metal Transfer in Two-Phase Aluminum Alloys,” Metal Transfer and Galling in Metallic Systems, H. D. Merchant and K. J. Bhansali, eds., The Metallurgical Society, Inc., pp. 131–153.
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