Gas Transmission NPRM. David Johnson November 10, 2016

Transcription

1 Gas Transmission NPRM David Johnson November 10, 2016

2 Friday the 13 th came 5 days early! 2

3 A few statistical facts As published in the FR: 136 pages like this 103 pages of intro & preamble 33 pages of proposed rules 52 enumerated changes or additions to Parts 191, 192 and Appendices many are multi-part 3

4 Definitions When I use a word, Humpty Dumpty said, in rather a scornful tone, it means just what I choose it to mean neither more nor less. The question is, said Alice, whether you can make words mean so many different things. The question is, said Humpty Dumpty, which is to be master that's all. ---Lewis Carroll, Through the Looking Glass RTVC used extensively but not defined Farm tap erroneously associated with gathering lines only Moderate Consequence Area like HCA with 5 houses, Occupied Site or (tbd) highway Occupied Site like Identified Site with fewer people (5/50) Legacy Pipe and Construction Significant SCC 4

5 Records: Materials Acquire and retain original pipe manufacturing records Life of pipeline retention Specs in effect at time of manufacture May require time travel capability 5

6 Records: Pipeline Components Manufacturing standard and pressure rating for Valves Flanges, fittings branch connections, extruded outlets, anchor forgings and other components with YS 42,000 psi 6

7 Installation of pipe in a ditch & Protective Coating For new pipeline or replacements > 1,000 ft. DCVG or ACVG survey within 3 months Repair coating damage within 6 months of survey > 35% for DCVG > 50 dbμv for ACVG Life of pipeline records 7

8 Other Corrosion Control Determine extent of LPA by CIS and confirm remediation by another CIS Extensive gas quality measurement and coupon monitoring for IC if gas may be potentially corrosive take remedial actions per B31G or RSTRENG if < 80% wall loss, based on PFP including class location factors. If pipe properties are not RTVC, go to

9 Spike Hydrostatic Testing Required if integrity threats cannot be addressed by ILI or DA Must use water Spike must be at least the lesser of o 1.50 x MAOP or o 105% of SMYS Must be in first two hours of 8-hour test Determine retest interval if time dependent 9

10 Verification of Pipeline Material Must have documented material properties for pipe, valves, fittings and components in o HCA, Class 3 and 4 OD, WT, YS, UTS, chem, seam, coating, mfgr spec One set of properties per mile Tests in 4 quadrants at each location Charpy testing also if needed for failure P, cracking Lots of details and specifics 10

11 Continuing Surveillance Adds inspection requirements following extreme weather events Inspection must start within 72 hrs of event cessation Extreme weather events not defined Type of inspection not specified 11

12 (e) MAOP For PL meeting (coming next!), establish and document MAOP by: 1. Pressure test (possible spike requirement also) 2. Pressure reduction 3. ECA 4. Pipe replacement 5. Pressure reduction small PIR and OD 6. Alternative technology 12

13 (a) & (b) MAOP Must use one or more of Methods 1-6 for PL Experienced reportable incident after most recent Subpart J test due to M&C defect, cracking, SSWC o In an HCA, Class 3 or 4 location, or piggable MCA Subpart J records are not RTVC in o HCA, Class 3 or 4 location, or MAOP by (c) in HCA, Class 3 or 4 or piggable MCA Any of these criteria are triggers Plan complete within 1 year 50% of mileage complete in 8 years, all in 15 years 13

14 (c) MAOP Determination 1. Pressure test to class location factor, at least 1.25 o Spike test likely required 2. Pressure reduction highest operating pressure/1.25 o Other factors for class locations and changes 3. ECA fracture mechanics principles 4. Replacement 5. Pressure reduction small PIR and OD o Patrols and instrumented leakage surveys o Monthly in Class 1 & 2, weekly in Class 3 + Odorize 6. Alternate technology o may be required 14

15 (d) Fracture Mechanics Analysis If any reason to believe susceptible to cracks or crack-like defects Must perform fracture mechanics modeling for failure pressure and crack growth remaining life If estimating size of defects that could survive hydro, must assume high CVN (larger surviving defects) If using ILI, must assume minimal properties smaller surviving defects Must reevaluate before 50% of remaining life reached If < 5 years, must perform hydrostatic test or reduce MAOP 15

16 Assessments Applies to non-hca Class 3 & 4 and piggable MCA Can use for MAOP verification if (c) is met Initial assessment identify anomalies and defects for each susceptible threat ILI corrosion, deformation and mechanical damage, cracking and any other threats Subpart J pressure test maybe spike test Guided wave UT EC, IC & SCC DA as last resort Other technology EC and IC requirements for < 30% SMYS 16

17 Assessments Analysis by demonstrably qualified person to identify condition that could adversely affect pipeline Consider all uncertainties Remediate per 713 if could adversely affect Must consider ALL available information 17

18 Repair Procedures Non Integrity Management repairs Correct conditions as prescribed in If an immediate hazard Reduce operating pressure to safe level o < 80% of pressure at time of discovery Additional measures to protect persons & property 18

19 Permanent Repair Applies to all transmission additive to Subpart O (?) Immediate o Predicted Pf < 1.1 x MAOP o Dent with metal loss, cracking or stress riser o Metal loss > 80% of wall o Metal loss on ERW or EFW seam o Significant SCC or SSWC o Reduce pressure until repairs complete 19

20 Permanent Repair 2 Year Conditions o Smooth dent >6% of OD on upper 2/3 o Dent >2% of OD affecting girth or seam weld o Predicted Pf 1.25 in Class 1, 1.39 in Class 2, 1.67 in Class 3 and 2.00 in Class 4 with uncertainties o Corrosion > 50% of wall o Gouge or groove > 12.5% of wall Monitored o Bottom 1/3 dent < 6% of OD o Upper 2/3 dent > 6% of OD but < critical strain level 20

21 Pig Trap Safety Device for safely relieving pressure in barrel before opening And Use suitable device to indicate pressure relief or Provide means to prevent opening if pressure not relieved 21

22 Identify & Use Threats Must identify and evaluate ALL potential threats To do this, must gather, verify, validate and integrate data on entire pipeline that could be relevant on covered segment Data must include list of 36 enumerated items some multi-part Must correct for SME bias Identify and analyze spatial relationships Analyze data for interrelationships among threats 22

23 (c) Risk Assessment If you re using one model, you re probably going down the wrong path Steve Nanney, Analyze identified threats and potential consequences, including interactions Ensure validity in light of operator & industry history Sensitivity analysis probability & consequences Determine additional P&M measures and their relative impacts and values 23

24 (c) Risk Assessment Help decisions to reduce risk, not just find highest risk Data, threat evaluation, interactions, predictive Lots of heartburn over this because: Belief that enough good data and good models will prevent failures is wrong. Very poor at predicting the large consequence, low frequency (not probability) events This subject needs creative thinking, but not getting it 24

25 (c) Risk Assessment The risk assessment must: 1. Analyze how failure could affect HCA, including worst case analysis 2. Analyze impact of each threat or risk factor and each combination that interact or contribute 3. Better understanding of threats, failure mechanisms, mitigation effectiveness and how to reduce 4. Account and compensate for uncertainties 5. Evaluate risk reduction associated with activities such as P&M measures and reduced intervals 25

26 (e) Risk Assessment Must include cyclic fatigue analyses Must include M&C defects may require MAOP reconfirmation If low-f ERW, lap weld, or any pipe with seam factor < 1.0 AND has experienced a seam failure or a pressure increase Must assess with technology for seam integrity and seam corrosion anomalies Prioritize as a high risk segment for baseline and subsequent assessments 26

27 Address Integrity Issues Immediate o Predicted Pf < 1.1 x MAOP o Dent with metal loss, cracking or stress riser o Metal loss > 80% of wall o Metal loss on ERW or EFW seam o Significant SCC or SSWC o Reduce pressure until repairs complete 27

28 Address Integrity Issues 1 Year Conditions o Smooth dent >6% of OD on upper 2/3 o Dent >2% of OD affecting girth or seam weld o Predicted Pf 1.25 in Class 1, 1.39 in Class 2, 1.67 in Class 3 and 2.00 in Class 4 with uncertainties o Corrosion > 50% of wall o Gouge or groove > 12.5% of wall o Non-immediate crack-like defect 28

29 Additional P&M Measures Must take measures beyond those already in 192 Must be based on the risk analysis in & include Correction of past deficiencies, ASV/RCV, LD systems, patrols, hydrotests, properties, coating, depth, etc. Address outside force IC monitoring, inhibiting and removal EC interference, CP & test stations, coatings 29

30 Web Locations Advisory Bulletins Rulemakings Notices Final Rules Regulatory Agenda 30

31 I saved this for last again because at this point, we re pretty much done. 31

32 Questions 32