Proposed regulatory alternatives

1
Proposed regulatory alternatives

• Class location change
• Other risk control projects

2
Pipeline map of class chg area
3
Class location change30 main line -L154
4
Class location change30 loop line L-254
5
Corrosion technology evaluation

• Will closely parallel PRCI initiative but will be
  independent of PRCI study
• Objective is to carry out a comparative study on
  the various techniques available in
• identifying coating anomalies
• quantifying corrosivity
• identifying and quantifying metal loss

6
Corrosion technology evaluation

• Techniques that will be considered
• close interval survey (on only)
• interrupted close interval survey (fast cycle)
• interrupted close interval study (slow cycle)
• close interval survey with side drain meas.
• direct current voltage gradient (DCVG) survey
• pipeline current mapping
• waveform analysis
• pearson survey
• C-scan and electromagnetic soil resistivity

7
Corrosion technology evaluation

• Industry experts in a joint approach will conduct
  this evaluation
• CSIR North America
• TEPSCO
• If logistics can be worked out, this evaluation
  will be conducted in coordination with planned
  smartpig runs on lines L-154 and L-254

8
Corrosion technology evaluation

• If smartpig results indicates bellhole
  inspections are needed to further evaluate
  indications, 1-2 of these locations would be used
  as a test site to compare information from
  techniques being evaluated prior to escavation

9
Corrosion technology evaluation

• Project details
• all techniques will be applied according to
  standard industry practices and/or manufacturer
  specifications
• A distinction will be made between close
  interval techniques and wide interval
  techniques (waveform, PCM, C-scan)
• In order to avoid any discrepancies in terms of
  positional correlations, all anomalies will be
  identified using differential GPS

10
Corrosion technology evaluation

• Project details - continued
• DCVG will also be used to provide additional
  information on possible shielding effects
• The use of elctromagnetic soil resistivity
  measurements will be included as a technique
  aimed at obtaining information on the possible
  corrosivity of the soil environment. These
  results will be correlated with the results
  obtained from the other techniques listed

11
Corrosion technology evaluation

• These tests will be performed on approximately a
  3 mile section of pipeline in the proximity of
  the proposed class location alternative area near
  Church Rock, NM
• TW is especially interested in determining if any
  of the techniques can provide additional
  corrosion control information regarding the
  bottom half of large diameter pipe

12
Corrosion technology evaluation

• TW will plan to conduct additional surveys on
  lines L-154, L-187, and L-176 having known
  disbondment with technique(s) identified that
  will provide measurable additional information
  regarding coating condition

13
Evaluation of coating survey techniques
Resistance bond to a foreign pipeline
Holidays at varying locations around the pipe
3 to 5 miles
000
100
200
300
400
600
700
Varying size and shape holidays
High resistance short to ground
Pearson Survey Close Interval Survey (On) Close
Interval Survey (On-Off- Fast Cycle) Close
Interval Survey (On-Off - Slow Cycle) Close
Interval Survey with Side Drains DC Voltage
Gradient Survey (Pipe Camp) Pipeline Current
Mapping Waveform Analysis (TransWave)
14
Risk control activities planned for class loc chg
area

• Conduct geometry tool and in-line inspection
  (smartpig)
• Increase pipeline surveillance from monthly to
  twice monthly
• Install additional ROW markers with spacing not
  to exceed 500 feet where possible and practical
• Install new style ROW markers

15
Risk control activities planned for class loc chg
area

• Conduct depth of cover survey
• Increased emphasis on meeting with certain
  excavation contractors, local and county planning
  groups, and utilities operating in the area
• Install transwave equipment
• Conduct corrosion technology evaluation
• Conduct CP survey with instrument using results
  of corrosion technology evaluation

16
Risk control activities planned for line L-154

• Conduct geometry tool and in-line inspection
  (smartpig)
• Conduct CP survey with instrument using results
  of corrosion technology evaluation

17
Risk control activities planned for line L-154

• Where any class 2 or 3 areas exist, besides
  specific class change area, the following will be
  done
• Install new style ROW markers with spacing not to
  exceed 500 feet where possible and practical
• Increased emphasis on meeting with certain
  excavation contractors, local and county planning
  groups, and utilities operating in the area

18
Risk control activities planned for line L-254

• Conduct geometry tool and in-line inspection
  (smartpig)
• Where any class 2 or 3 areas exist, besides
  specific class change area, the following will be
  done
• Install new style ROW markers with spacing not
  to exceed 500 feet where possible and practical
• Increased emphasis on meeting with certain
  excavation contractors, local and county planning
  groups, and utilities in area

19
Risk control activities planned for line L-187

• Conduct geometry tool and in-line inspection
  (smartpig)
• Where any class 2 or 3 areas exist, besides
  specific class change area, the following will be
  done
• Install new style ROW markers with spacing not
  to exceed 500 feet where possible and practical
• Increased emphasis on meeting with certain
  excavation contractors, local and county planning
  groups, and utilities in area

20
Risk control activities planned for line L-187

• Conduct CP survey with instrument using results
  of corrosion technology evaluation
• Install subsidence monitoring equipment at
  mainline valve assemblies where currently not
  present
• Increase pipeline surveillance from monthly to
  twice monthly

21
Risk control activities planned for line L-176

• Conduct geometry tool and in-line inspection
  (smartpig)
• Where any class 2 or 3 areas exist, besides
  specific class change area, the following will be
  done
• Install new style ROW markers with spacing not
  to exceed 500 feet where possible and practical
• Increased emphasis on meeting with certain
  excavation contractors, local and county planning
  groups, and utilities in area

22
Risk control activities planned for line L-176

• Conduct CP survey with instrument using results
  of corrosion technology evaluation
• Install subsidence monitoring equipment at
  mainline valve assemblies where currently not
  present
• Increase pipeline surveillance from monthly to
  twice monthly