1 / 16

Fatigue Performance of High Strength Riser Materials RPSEA Project No. DW 1403

Fatigue Performance of High Strength Riser Materials RPSEA Project No. DW 1403 TAC Quarterly Meeting June 2, 2009 Houston, Texas Presented by Stephen J. Hudak, Jr. Materials Engineering Department Southwest Research Institute. Research Partnership to Secure Energy for America.

early
Download Presentation

Fatigue Performance of High Strength Riser Materials RPSEA Project No. DW 1403

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fatigue Performance of High Strength Riser Materials RPSEA Project No. DW 1403 TAC Quarterly Meeting June 2, 2009 Houston, Texas Presented by Stephen J. Hudak, Jr. Materials Engineering Department Southwest Research Institute Research Partnership to Secure Energy for America

  2. Project Objective • Assess the fatigue resistance of new high strength HPHT riser materials in representative environments • Fatigue Crack Growth Rates (FCGR) • Classical S-N fatigue life • Environments • Air (baseline) • Sour brine • Seawater

  3. Materials MaterialYS, ksiSourStatus 1 114 ksi yes Specimens machined; frequency-scan tests complete 2 131 ksi yes Specimens machined; frequency-scan tests complete 3 ~125 ksi yes Awaiting material 4 132 ksi no Specimens machined; frequency-scan tests complete 5 156 ksi no Specimens being machined 6 ~120 ksi yes Awaiting material

  4. Environments • Lab air (baseline): 70-75°F, 40-60% RH • Seawater: ASTM D1141 substitute ocean water open to the air with cathodic protection: - 1050mv vs. Saturated Calomel Electrode • Sour Brine: Production brine with oxygen below 10 ppb and 35% H2S + 65% CO2

  5. Task 1: FCGR Testing • Frequency scan (FS) tests at Constant-DK to determine optimum cyclic loading frequency for subsequent testing • FCGR testing as a function of DK to determine cracking kinetics that can be used in fracture mechanics design and/or fitness-for-service assessments

  6. FCGR Specimen

  7. Task 1: FCGR Test Matrix • Total FCGR tests 10 15 9+3 Grand Total: 34+3 • Orange = tests completed • Red = tests not in current SOW * Materials in-hand

  8. Frequency Scan Testing Seawater • Corrosion fatigue performance sensitive to loading frequency • Fatigue crack growth rates at constant-DK used to characterize frequency effect in frequency scan (FS) tests 13x

  9. Seawater vs. Sour Brine Seawater YS = 114 ksi Sour Brine 6X 24X

  10. Seawater vs. Sour Brine Seawater YS = 131 ksi SourBrine 15X 250X

  11. Material-Environment Interactions Corrosion-Fatigue Acceleration* vs. Air Baseline Yield Strength, ksi 114 131 132 Environment: Sour Brine Seawater 24X 250X --- 6X 15X 15X * At DK= 20 ksi√in. R=0.5 and Frequency = 0.01 Hz

  12. Frequency Response vs. YS Sour Brine Seawater Air Baseline Air Baseline

  13. Last-Quarter Progress • Procured four of six test materials – at no cost to project • Completed specimen machining on three of six materials • Specimen machining on fourth material is in-progress • Completed frequency scan tests on 62% of material-environment combinations • Analyzed frequency-scan data and identified the importance of material strength level on corrosion-fatigue resistance • Determined that saturation frequency likely depends on material-environment combination • Machined grips for baseline air tests to be performed at NETL-Albany, Oregon • Initiated air S-N testing at SwRI to assess inter-laboratory reproducibility with NETL • Took receipt of ConocoPhillips Ti-alloy data base

  14. Schedule

  15. Costs RPSEA Contract Amt $800K BP Cost Share $200K Total Contracted Amt $1,000K Costs to Date $218K Balance $782K

  16. Next-Quarter Plan • Procure remaining two test materials • Machine remaining specimens • Complete frequency-scan tests • Meet with PWC to select optimum test frequencies • Complete air S-N tests at SwRI • Initiate air S-N tests at NETL • Initiate seawater S-N tests • Initiate sour brine S-N tests • Initiate air FCGR tests • Initiate seawater FCGR tests • Initiate sour brine FCGR tests

More Related