Join Blade Energy Partners at the 35th Annual PPIM Conference and Exhibition. We will be at BOOTH #143.

Since 1989, attendance at the annual PPIM Conference and Exhibition in Houston has grown from a few hundred to more than 3,500, including a commercial exhibition that began with a handful of specialized solution-providers and which now involves more than 190 companies and industry organizations from more than 25 countries.

In parallel with the demands for greater pipeline safety, reliability, and efficiency – and the explosive growth in the market for technologies to help meet those demands – PPIM has evolved to become the industry’s primary forum for reporting new developments and field experience, and for showcasing the relevant tools and systems. It is the place where the needs of pipeline operators and the capabilities of service and equipment suppliers intersect.

Information exchange at PPIM is supported by a range of educational technical courses that take place in advance of the conference and exhibition. Led by a distinguished faculty including the world’s top experts, the courses provide a foundation for well-informed inquiry and dialogue among industry colleagues, clients and contractors.

Wednesday, February 8

1.0 Plenary – Opening Session

9:30 AM:

3. Your API 5L Vintage Line Pipe Fracture Toughness Data Would Likely Fall Within This Range

Sergio Limon1, Carlos Madera2, Kevin Coulter3, Ken George4, Ravi Krishnamurthy4

1Blade Energy Partners, Salt Lake City, UT, USA. 2Dow Chemical, Angleton, TX, USA. 3Dow Chemical, Freeport, TX, USA. 4Blade Energy Partners, Houston, TX, USA


When assessing structural integrity of energy pipelines with cracks and seam weld defects, we are interested in the tolerance of the line pipe material to resist fracture in the presence of a planar defect. This material characteristic is known as fracturetoughness. There are two sources of fracture toughness data commonly used in the pipeline industry: toughness measured from a starting blunt notch loaded dynamically and fracture toughness obtained from a starting sharp crack subjected to quasi-static loading. Often, neither of these two types of toughness are available for a pipeline for which an engineering planar defect assessment is to be performed. Therefore, conservative assumptions would need to be made.

A fracture toughness database comprised of nearly one hundred J-integral toughness data measured from API 5L pre-1980s ERW/EFW line pipe samples was analyzed. The fracture toughness tests were conducted in accordance with ASTM E1820 at room temperature. The analysis of these J-integral data point to ranges of seam weld bondline and pipe body toughness values that can be used in engineering assessments of pipelines with planar defects. The fracture toughness ranges are expressed in terms of Mean and Mean ± StandardDeviations. These values will support using lower bound toughness assumptions while avoiding the reliance of overly conservative toughness data. Recent J-integral toughness data from pre-1980s ERW/EFW pipe fall within these ranges. All J-integral toughness tests were conducted using a standardized sub-size test specimen and the transferability of fracture toughness results from sub-scale testing samples to full-scale pipe conditions are explored in the paper.

Thursday, February 9

8.2 Stress Corrosion Cracking

11:00 AM – Session chair: Dr. Fan Zhang, Phillips 66

66. Fatigue Testing (Small and Full Scale) Validation of SCC Recoating

Ryan Milligan¹, Ming Gao¹, Ravi Krishnamurthy¹, Richard Kania², Elvis Sanjuan²

¹Blade Energy Partners, Houston, USA, ²TC Energy, Calgary, Canada


For gas pipelines it is important to identify SCC colonies that can be recoated without grinding and operate for another 50+ years. One of the key elements of this study was the small scale and full-scale fatigue testing of SCC colonies for validation. Thefocus of this paper is on the testing methodology and results.

The fatigue testing was conducted in the base metal, weld and HAZ. Small scale testing was first utilized to establish the baseline behavior along with J-R data. The full-scale testing was conducted in pre-existing SCC colonies in the base metal and utilizedapplication of hydraulically pressurized water.

For the weld region, SCC cracks were not adjacent to the weld, consequently a crack was generated using an EDM notch. The crack growth in the full-scale ring-samples was generated using a servo-hydraulic machine. This required development of a specializedK solution using FEA.

The nature of the fatigue cracking was matched between small- and full-scale testing using SEM analysis of the fracture surface. Integrated analysis of the small scale, full scale and fractographic results validated more than 50 years of remaining fatiguelife for recoated SCC cracks in gas pipelines.

8.4 Crack Assessment & Management 3 

4:00 PM – Session chair:

72. Failure Analyses and Consequent Mitigation: Case Studies

Ming Gao¹, Ravi Krishnamurthy¹

¹Blade Energy Partners, Houston, USA


It is well established that pipelines have the fewest fatalities of any of the various modes of transportation. Failures do occur, however, for a variety of reasons. In this paper, cases of failure due to SCC, weld defects and hydrogen-assisted cracking areanalyzed with interdisciplinary approach that combines metallography/fractography, environmental chemistry, fracture mechanics and hydrostatic/ILI based assessment to identify root cause of the failures. Lessons learned from each of the cases analyzed serveas a basis for development of improved integrity management plan for prevention and will be presented in the paper.

For illustration, analysis of an onshore natural gas pipeline that failed recently in South America is shown here. Fractographic analysis with high-resolution matting fracture surface technique identified hydrogen assisted cracking is the mechanism for thefailure while the source of hydrogen was driven by cathodic protection operated at near − 1200 mV CSE. Microstructural analysis showed no hard spots associated with the failure. API 579 FAD Level-3 tearing instability analysis confirmed that critical cracksize was 90% deep x73 mm long that is consistent with macro-fractographic analysis based on chevron marks and the failure pressure. From the lesson learned, improvement of the distribution and control of the cathodic protection current is critical to avoidhigh generation of hydrogen at sites where the coating is broken or has faults