# Presentation: 342515

## OPS ECDA Workshop

- David Berger & Alan Eastman
- KeySpan Corporation
- Pacific Gas & Electric
- Houston, TX
- November 4, 2003

**Notes:**
Thanks for giving us the opportunity to present our respective company’s DA programs. We are first going to view a brief, something for people who know Alan and I are not, and then we will review how each of companies approach this challenging task. 

SHOW THE MOVIE	

I do not think that this would get an Academy Award, but we think it gets the point across. 

Our presentation is going to give you an idea on how two companies are doing DA. One is on the East Coast and the other on the West Coast. One is primarily an urban and suburban gas utility, the other is all that plus has many miles of rural pipelines and an electric T&D component.

On to the presentation

## KeySpan Gas TransmissionSystem Summary

_**	**_
- Less than 20%
- 20 to 30%
- Greater than
- Totals

_**SMYS**_

**Distance (miles)**

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**Notes:**
Here is the breakdown of the transmission system for KSE. As you can see, only 6.2% is greater than 30% SMYS and a third is under 20%. These are based on the NY State definition of a transmission pipeline which anything above 124#s.

Not only are pipelines in NY cover by CFR 192, but a more stringent code, NYCRR 255 is also in force. This code predates 192 and has other stipulations.

## PG&E Gas TransmissionSystem Summary

- Class 1
- Class 2
- Class 3
- Class 4

**Distance (miles)**

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**Notes:**
ADD Slide with PGE System and Alan to provide write up.

## IMP Tools

- Pressure Test
- In Line Inspection (a.k.a. Pigging)
- Direct Assessment (a.k.a. DA)
- Other

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**Notes:**
Gas pipeline operators have 4 methods they can use to determine the integrity of their pipelines. 

For KSE, everyone of our pipelines, including the ones installed in the early 1950’s had some kind of pressure test. It may not have been to 150% of the MAOP, but it was at least the MAOP. NYS also has a use it or lose it clause in its codes. 

Most LDC pipelines built before the 1990’s were not designed to be pigged. Many have valves that are not full bore, they have back to back elbows, tight diameter bends and no gates on tees. For an LDC, the choice is pressure test, DA or re-configure the pipeline

## ECDA Process

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**Notes:**
We are going to talk about the ECDA process today. The other options to determine pipeline integrity have been discussed in other forums or are very well understood.

This graph shows the 4 step process that was developed into the NACE RP.

## ECDA Steps

- Step 1 - Pre Assessment - Dave Berger
- Step 2 - Indirect Examination - D. Berger
- Step3 - Direct Examination - Alan Eastman
- Step 4 - Post Assessment - A. Eastman

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**Notes:**
The steps are very logical and most of the techniques and science behind them is well known and documented. What is new is putting them all together in a procedure that documents each step, adds the results together and is self correcting.

## ECDA Step 1 - Pre Assessment 

- Determine what you know about the main in Question
- Determine what threats are being encountered

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**Notes:**
The pre-assessment step is one of the most critical. It can make the entire ECDA very effective or can reduce the effectiveness. If not done properly, it can cause large additional costs for minor benefits. It is critical for making this process both effective and cost efficient.

At KSE we did a complete records search for each of our pipelines. We found and reviewed the construction records and read the project engineers daily notes. We reviewed not only the current drawings, but all of the historic drawings to make sure no details were omitted with out reason.

Check with operating people for any recorded or known problems, such as over pressure, leaks, etc. Check with corrosion personnel to see if line always had CP and was it adequate. Are there areas that seem to be have a problem with maintaining good CP. Review test data.

On threats, for this particular segment or area, is there a threat that is special. For most urban LDC’s damage (from first, second or third parties) may be the most significant threat to the segment. Do not discount Internal corrosion just because you have good quality gas now. What about when the pipeline was installed. Was it all pipeline quality gas or was there some manufactured gas. Not only look at current threats, but look at past ones to understand the stress that the pipeline has encountered.

## ECDA Step 1 - Pre Assessment 

- Determine the Relative Risk of this Segment
- Run Risk Model if Available

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**Notes:**
Under B31.8 S, you have several options to determine the relative risk of a pipeline. 
You can use subject matter experts, such as which pipeline would you not like to live next to, or you can use several available models. We are using a model developed by John Keifner for NGA and with the concurrence of the NYS PSC. We are also using a model from Moulbauer. Lastly, we will review the data out of these models with the subject matter experts. 

Although the pre-assessment step looks easy, it can be the make or break step that turns an ECDA project from good to great or from acceptable to unacceptable. It is the pay me now or pay me latter. Once the data is obtained in Step 2, it needs to be organized and reviewed with an eye on what has transpired and what the threats have been and are now. 

## Step 1   Pre-Assessment

**Step 1   Pre-Assessment**

**Is the ECDA process technically, practically and economically feasible ?**

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## IIT Selection Tool Form 

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## Region Assignment Form

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## ECDA Step 2 - Indirect Examination

- Tool Selection based on Pipe and Threats
- Integrate Pre-Assessment information into Indirect Exam Process
- Pipe Region
- Tool Types
- Expected Results
- Data Collection

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**Notes:**
Before I get into tool selection, let me go over the spacing of the testing. Each tool has certain requirements for testing spacing. For CIS, the definition of close is very important. People use this from 25’ to 2’. We at KSE use to look at 50’ so as to minimize the drilling of holes in paved area. We have found that could miss significant areas of concern, We moved it to 25’ and  showed that everything that showed up at 5’ would show up at 25’. Based on this, we are going to do 10% of each segment at 5’ and check if we used 25’ would we see everything. If so, then the rest of the pipe can be done at 25’, if not all CIS on that pipe is at 5’ spacing. Doing work in an urban environment has one advantage, we can paint dots on the road or sidewalk every 5’ and have a perfect match on our different techniques.

The next slides shows the same area at 5’ and 25’ intervals.

## Step 2 – Indirect Examinations

- Step 2 – Indirect Examinations

_**Other Logistical Issues:**_
** ****Home owner notification**
** ****CIS through asphalt**
** ****City permits**

- Dear Landowner,
- Recently we sent you a letter notifying you that we would be performing some testing of the natural gas pipeline on your property.  As a reminder, the testing will not cause an interruption of your gas service.
- We are planning to be testing the pipeline in your area next week.  If we need to gain access to your backyard, we will contact you in person at the time of the testing.  In the event that nobody is home, we will plan to come back and test your property at some future date, most probably on a Saturday.  However, please contact our testing Contractor, Mears, at 925-820-7630 if it is acceptable for us to enter your backyard and perform the testing in your absence.  The testing will only take approximately 5 minutes per residence.
- Thanks for your cooperation.
- PG&E

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## 25’ Interval

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**Notes:**
Here is the 25’ case. This is 33’ year old 8” coat tar coated API 5L pipe that is currently undergoing an uprating from 124# to 350#. 17 miles of pipe are being assess and it was installed from 1966 to November 2003.

## 5’ Interval

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**Notes:**
Here is 5’ case. In this graph you can see all of the testing that has been completed and each of the dips and highs of the CIS are very evident. The coating is the main driver on the distance for a CIS. Another driver is soil conditions. The NACE RP suggests that the distance be the same as the depth. In some cases this may apply, but in many it may be an over kill.

In KSE because the digs are so expensive, we tend to do several re-tests over an area before doing the dig. We also are now using the ‘A’ Frame, an ACVG device to pinpoint the size and location of the coating defect.

## ECDA Step 2

- Tool Selection based on Pipe and Threats
- Major Threats to LDC’s are Corrosion and Third Party Damage
- External Corrosion
- Internal Corrosion (Dependent on gas quality)
- SCC Not a Problem
- First and Second party Damage also an issue

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**Notes:**
Now to the easy part. What tools do I use and what do I expect to find.
Tool selection can be  as easy as what works for the pipe in question (why pick a tool that does not work?). For areas with a lot of paving, tools that look through paving are a great choice, especially if they find damage that is characteristic of the threats encountered. For us, we use at least two and many times three to zero in the damage. 
We use CIS at a certain spacing and a complementary method. The preferred one is Electro-mechanical attenuation (PCM) with a low frequency AC signal. This will ‘see’ through paving and will show coat breaks on a macro level. When coupled with ACVG, we have been very successful with reducing the size of our openings and finding the holiday. With external corrosion and third party damage the two big threats, each would probably have a coating holiday.

## ECDA Step 2

- Integrate Pre-Assessment information into Indirect Examination Process
- Check for CP History
- Coating Type and Recent Examinations
- Tool Environment
- Special Situations

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**Notes:**
If you have good pre-assessment data, then the indirect exam can be a fast and yield good conclusions. If you do not have a good idea of the what is in the ground and how well it has been protected, additional testing may be necessary. This would be the case if digs are expensive. If digs are not expensive, then additional digs may be needed to provide historic data on the CP and coating condition.

Casings, major road crossing and creek crossings need to evaluated on a case by case basis. Some data may be inferred by readings at both ends. In other situations, test holes and additional readings  or techniques may be necessary. There is NO ONE SIZE FITS ALL.

## ECDA Step 2

- Pipe Region
- Tool Changes Requires Region Change
- Soil Type and Corrosion History May Change Region
- Coating Type May Change Region
- Pipe Type May Change Region
- Pipe Diameter May Not Change Region
- Threat Change Requires Region Change

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**Notes:**
This is directly from the RP. As Mr. Drake has said many time, does it pass the red face test? Changing tools changes the calibration of the DA. Coating behave differently and can give different results with different tools. Tape and FBE do not give the same results to DCVG.

You are measuring for coating defects, the underlining steel and diameter (except for the change in magnetic flux) are not important. How the coating acts in the soil is.

## ECDA Step 2

- Tool Types
- CIS: DC Electrical
- PCM: Near DC but AC
- DCVG: DC Gradient
- ACVG: Near DC but AC
- Soil Resistivity: Corrosion Rates
- Bacterial: MIC Presence
- C scan: AC Electrical

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## ECDA Step 2

- Expected Results
- Based On Threats, What do You Expect to Find
- For Corrosion
- Coating Damage, Disbondment, Shielding
- In Areas with Poor CP, External Corrosion
- With Wet Gas, Internal Corrosion
- Near Dumps, MIC
- Third Party Damage
- Coating Damage (Maybe Pipe Damage)

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## ECDA Step 2

- Data Collection
- Manual or Automatic
- Data Storage
- Data Retrieval
- Data Displays

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## GM 33

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## GM 33

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**Notes:**
Here is 5’ case. In this graph you can see all of the testing that has been completed and each of the dips and highs of the CIS are very evident. The coating is the main driver on the distance for a CIS. Another driver is soil conditions. The NACE RP suggests that the distance be the same as the depth. In some cases this may apply, but in many it may be an over kill.

In KSE because the digs are so expensive, we tend to do several re-tests over an area before doing the dig. We also are now using the ‘A’ Frame, an ACVG device to pinpoint the size and location of the coating defect.

## GM 33

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## GM 33

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## GM 33

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## Part 2

- Now Alan will take you through the next two steps

## Indirect Inspection Classification(example)

- CIS Severe......All of the following must exist:
******  ****Less than 600 mv off**
******  ****200 mv depression over baseline**
******  ****Convergence of on/off potential**
******  ****Other condition that the PE wants to document**
******  ****<500 off (any case)**
** **
- CIS Moderate......All of the following must exist:
******  ****Less than 600 mv off**
******  ****200 mv  depression over baseline**
******  ****Other condition that the PE wants to document**
** **
- CIS Minor......Any of the following can exist:
******  ****Between 600 to 850 mv off**
******  ****Other conditions that the PE wants to document**
** **
** **
** **
** **

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## Prioritization Criteria

**I = Immediate**
**S = Scheduled**
**M = Monitored**
**NI = No Indication**

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## CGT Scope

**2192 miles to assess 1673 miles of “covered” transmission lines**
**  ****1,273** miles of ECDA
- 	 ($35,177,000)
-      **394** miles assessed during 913 miles of ILI
- 	 ($98,500,000)
-       **6.5** miles of Pipeline Replacement
- 	($6,500,000)

***2004 Scope***

** ****ECDA – 117 miles ($5.8 million)**
** ****ILI – 79 miles ($12 million)**
** ****CIS – ($400,000)**
** ****Pipe Replacement – ($2,000,000)**

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- All pipeline companies will allocate the appropriate resources to ensure the integrity pipelines with the highest consequences of failure

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## Step 3 – Direct Examination 

- Number of excavations per RP0502
- All immediate indications must be excavated (may be re-prioritized after a portion is excavated)
- At least 1 scheduled dig per region
- Effectiveness digs
- First ECDA digs

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## Direct Examination

- Inspections
- Remaining Strength Assessment
- Root Cause Analysis
- Reprioritization

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## Recategorization

**Work In Progress**

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## Post Assessment

- Remaining Life Calculations
- Re-Assessment Intervals
- ECDA Effectiveness Validation
- Documentation

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## Lessons Learned

- Establishment of ECDA procedure has been a corner stone of program
- Permit Applications time consuming and challenging
- Landowner Notifications time consuming
- Establishing GIS procedure is critical
- IIT methods work
- IIT  results has aligned well and is rational
- ECDA process appears to be working well
- We are sure there are more lessons to be learned!!

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## Example of an ECDA Line 132 Through Silicon Valley

- _Selection Criteria_
- Identified by Risk Management Program
- Primary Threat – EC
- Not piggable
- 8 OD changes
- 10 plug valves

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## L-132 Near Major Theme Park

- 20 mile section in study area
- 24-34 inch, 400# MAOP, 20 to 40% SMYS, 1944 HAA, 1974 Tape
- 13 Integrity Management Areas (IMAs)
- 6300’ under streets,
- 6000’ under concrete,
- 4950’ under soil,
- 2300’ in paved parking,
- 2150’ in backyards

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## Results of Classification

** ****Good alignment between techniques**
** ****CP was protecting poorly coated section of pipe**
** ****Results appear rational**

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## Results of Prioritization

**Total of 10 Excavations **

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## Example of Line 132 Excavation Data

- Data Element			Dig 1			Dig 2
- ECDA Region			132-1			132-2
- Coating Type			Wrap			HAA
- Pipe-to-Soil (-mV)		1051			971
- Soil Resistivity			   684			684
- Coating Condition	    Partially Disbonded		 Partially Disbonded
- Liquid underneath coating	Yes			Yes
- Soil pH				5.5			6.0
- Pipe pH				7.4			8.0
- Corrosion			No			Yes
- Pit Depth (inches)				0.015 to 0.031

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## Final Outcome

- 500 feet of recoating
- 1650 feet of pipe replacement
- Remaining indications reprioritized
- Re-assessment interval being determined

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## Site Three

- Poor Condition

- Excavated, removed coating, sandblasted

**Excavate 10 ft.**

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## Slide 44

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## ECDA

- The
- End
- (I Thought They would Never Finish)

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