1. 7A1 Friction & Galling Test
API SC5/WG Item 1033a
(or New Line Number)
7A1 Friction & Galling Test
STATUS: January 2010

2. Project Goals WG 1033a Budget Year 2001 Deliverables- Goal
The Goal of the project is to complete development & testing bench-top test for galling & friction for the API C1/SC5 test program.
GrantPrideco & Stress will generate data base comparing the new specimen assembly to full scale connections.
New recommendations for API will be documented & reported.

3. WG 1033a Project Goals Budget Year 2002 Status of Deliverables
The Goal of the project to complete development & testing bench-top test for galling & friction for the API C1/SC5 test program. STATUS: The equipment shows good correlation but many problems are encountered with the Honeywell load cells and with bolts breaking.
GrantPrideco & Stress will generate data base comparing the new specimen assembly to full scale connections. STATUS: Data was generated with full scale connections but problems were encountered with tong slippage and the placement of the strain gauges on the full size connections.
New recommendations for API will be documented & reported. STATUS: Due to the issues with bolt and load cell reliability no formal recommendations were able to be drafted. The group will work to isolate the causes and make recommendations to resolve.

4. GOAL OF DRAFTING A PROCEDURE
The goal of drafting a procedure was not met due to failures in several of the assembly components. The work group felt drafting a procedure in which flaws were known was not to the benefit of the API Community. Although correlations are superior to the current 7A1 specimen set, the procedure was not ready to draft.

5. WG 1033a Project Goals Budget Year 2002 Deliverables
The Goal of the project is to establish standardized performance tests for evaluating the suitability of Environmentally acceptable thread compounds.
Full Scale product performance experiments designed for comprehensive evaluation of any thread compound would be made.
Identification of small scale test methods for friction and galling will be more fully evaluated and compared to available full scale data.

6. Project Goals WG 1033a Budget Year 2002 Status of Deliverables
The Goal of the project is to establish standardized performance tests for evaluating the suitability of Environmentally acceptable thread compounds. STATUS: The equipment continues to show good correlation but problems are still being encountered with the Honeywell load cells and with bolts breaking. Omegadyne load cells were purchased.
Full Scale product performance experiments designed for comprehensive evaluation of any thread compound would be made. STATUS: Full data reports were distributed to JIP participants and the API and can be available for other interested parties .
Identification of Small scale test methods for friction and galling will be more fully evaluated and compared to available full scale data.
STATUS: Evaluations of the bench scale test equipment continue with the goal of the group to isolate the causes and make recommendations to resolve.

7. Current Project Goals WG 1033a
The Goal of the project is to provide a RELIABLE bench-top test which correlates to full scale drill string connections.
Evaluate whether the apparatus or procedure can be modified to provide a correlation to API noninterference and proprietary mechanical seal tubing & casing thread designs
Utilize the bench top test apparatus to measure relative galling resistance of thread compounds.

8. WG 1033a - CURRENT STATUS –
The current goal is to fabricate the new Jet-Lube/Stress Engineering Services specimen set design which utilizes a 1 ¼ inch bolt to eliminate issues with the 1 inch.
Move the API Committee torque turn equipment from Stress Engineering Services to Texas A&M University.
Generate a formal proposal from Texas A&M University to do the project work in The formal proposal would include itemized list of raw materials to purchase or fabricate, what compounds or types to test, list the required tests and time for preparing the reports.
Compare the data to full scale connection data run on the same products as shown on next slide deliverables.

9. Deliverables with API Funding
Friction & Galling resistance test assembly or assemblies;
- For Rotary shouldered connections, more substantial assembly for measuring contact pressures up to 150K
- For noninterference connection designs such as 8-round or buttress the current assembly in test for contact pressures up to 55K using spring disk washers and load cell for greater sensitivity in this contact pressure limit.
- For proprietary mechanical seal connection designs a new assembly to test for contact pressures up to 150K using spring disk washers and load cell.
- For galling resistance testing the current assembly has shown to correlate to full scale connections and coating wear.
To test the on the above a wide range of coefficients of friction on several thread compounds used in the past which showed the API RP 1 inch bolt did not work. These include a 15% PTFE nonmetallic compound, 60% lead reference compound, API RP 5A3 reference compound, a commercial nonmetallic (Yellow) compound for proprietary mechanical seal connection designs, 50% zinc and a high performance commercial Copper compound with 1.15 friction factor.

10. ACTION ITEMS
Complete design & fabrication of a test assembly which provides a correlation to field data on full scale thread designs. Current API RP 7A1 has very little correlation.
Test the suitability and reliability of the compressive load cell designed by Mr. Jack Smith of Stress Engineering Services for repeated loads of up to 150KSI. Alloys used: One of 4140, the other with 17-4PH
Replace the 60 percent lead reference compound which plates onto the specimens and has an effect on the subsequent compound test data.
See current API RP 7A1

11. Example of Obsolete API Bulletin 7A1 Test Apparatus

12. TORQUE CALIBRATION SUBS

13. API RP 7A1 SPECIMEN SET DESIGNS

14. 1992 RP 7a1 vs. Full Scale NC-46

15. Late 1990’s Small Rotary Shouldered Tool Joint Torque Turn Specimens

16. CURRENT FRICTION & GALLING TEST SPECIMEN SET DESIGNS

17. PROPOSED SPECIMEN SET DESIGN

18. PROPOSED ASSEMBLY DESIGN

19. 1st Attempt at 150K Load Cell

20. Next 150K Load Cell

21. ISSUES WITH CURRENT API RP 7A1 METHOD
PROPERTY
RESULTS
API RP 7A1 - 1 inch Bolt Specimen
Limited relative surface travel.
No correlation with nonmetal compounds
Current 60% Lead Reference Compound
Plates interfering with subsequent results, Toxicity
Current RP 7A1 Protocol
Cannot measure contact pressure
Comparison by slope at a set torque limit
Correct method should be to determine torque to achieve a desired load
Current Apparatus and method
Absolutely no correlation with Tubing and casing thread designs

22. ISSUES WHICH STILL NEED TO BE RESOLVED
Determine the composition & properties for a bolt lube with consistent COF
Determine whether the proposed enhanced specimen design eliminates current load cell, bolt & nut failures
Determine whether the new specimen design & bolt lube can test up to 150 KSI
Compare the results to full scale connection data

23. Coefficient of friction graphs for same product where only particle size varies. Experimental Batches 4343 (medium), 4344 (Std/Micro) & 4345 (larger size)

24. Torque Turn Graph for Typical Galling Test

25. Proposed Galling Specimen Showing Only Wear

26. Proposed Galling Specimen Showing Galling

27. Schedule
Review of expected schedule milestones with additional funding
Machine new load cell and get
it strain gauged & calibrated
Fabricate new assembly & purchase
Specimen sets &
Run Broad range testing
Complete data review
& draft test procedure
August
Oct
Dec
Feb
Apr
June
The timeline is based upon the expectation the proposed test assembly will not have long lead times to machine or purchase, will correlate well and allow many tests without components yielding.