Focus on

Trond Gjedrem and André Trostel¹

1. Introduction

Rising energy costs, shortage of resources as well as increasing demand and relocation of consumers have resulted in consistent growth of oil and gas pipeline construction during the last years. The BTC crude oil pipeline, which connects the oil fields in the Caspian Sea with the Mediterranean Sea and its international tanker routes, is one of the most ambitious projects in the previous years.

Figure 1: Overview Map – Course of Baku – Tbilisi – Ceyhan (BTC) Crude Oil Pipeline

The more than 1,700 km long track starts in Baku (Azerbaijan) and runs south of the Caucasus main crest over Tbilisi (Georgia) in a wide arc through the north eastern part of Turkey to end at the Turkish Mediterranean port of Ceyhan.
Thereby approximately 1,000 km, which means the main part of the pipeline, take course at the territory of Turkey. The project was awarded to international bidder consortia by Turkish contractor BOTAS (Petroleum Pipeline Corporation) in 3 lots with different length and complexity.

Figure 2: political overview map – Course of BTC Pipeline at Turkish territory – Lot A

The Turkish-Dutch bidder consortium TEPE / NACAP awarded SGS Gottfeld NDT Services and its projects department the contract for non-destructive testing (NDT) of girth welds at the 278 km long lot A running from the Georgian border to pumping station 2 near Erzurum.

Project construction began in August 2003 and was successfully finished for SGS Gottfeld with the last weld after 25 month mid of October 2005. First crude is supposed to reach the port of Ceyhan end of 2005.

2. Project Details

All procedures for pipe fabrication, handling and pipeline installation were geared to American standards and regulations like common within pipeline project business. For Occupational Health and Safety and Radiation Protection local regulations have been adopted. Work was executed by an international project team. Site languages were Turkish and English.

2-1. Pipeline Key Data

Length:	Total 1,760 km, 1,000 km at Turkish territory, Lot A 278 km
Dimensions:	46“ and 42“ with wall thickness from 10,8 to 23,8 mm, single pipe length 12 m
Material:	X60
Welding Method:	Manual and automated weld method Saturn ax, 180 to 200 welds maximum daily production in all 3 lot parts within Lot A

2-2. Technical task for NDT

Due to project size, economic and strategic impact and the challenging environmental conditions quality and adherence to delivery and installation dates as well as safety on site have been most significant. For the performance of non-destructive testing (NDT) and therewith also for Radiation Protection contractor BOTAS and its consultant ILF set up technical and organizational detailed guidelines. These had to be converted to site and company specific instructions during the project preparation.

Pipeline girth welds have been tested for failures with X-Ray 100% and 10% randomly spread with manual Ultrasonic equipment. For the control of the welding process and a smooth work flow of the subsequent assemblies – insulation and excavation – it was necessary to make the test results available to the contractor not later than 24 hours after production of the weld.

2-2-1. Radiographic Testing

Due to better image quality radiographic testing of girth welds has been only executed with X-Ray equipment. Based on weld type – front end weld at above ground prefabricated line or connecting welds and re-pairs – X-Ray crawlers have been used for single wall exposure and external tubes for double wall exposure.
Required was compliance to standards API 1104 – Welding of Pipelines and Related Facilities, Edition 19, 1999 and ASME Section V, Article 2.

Figure 3: Set up of X-Ray tube and Film according to ASME Section V, Article 2

Figure 4: Schematic Diagram of an X-Ray Crawler

Crawlers for front end welds as well as external tubes for connection and repair welds have been operated in teams of two with dedicated Pick-Up all-terrain vehicles. During high daily performance film runners have been used to transport the exposed films to the next darkroom container to assure efficiency of developing equipment also during the day and facilitate the adherence of timing for films and appropriate test reports.

Figure 5: Crawler running into a pipe at a strong downhill grade (Cableway pipe lay)

Film appraisal was executed by the most experienced members of the project team. Failure rate of welds was as commonly as known for this kind of pipeline projects. More than 25,000 films have been archived and treated to be stored at least 30 years to get access to the contained information at every time.

Figure 6: Set up of lead measuring tape and film at a front end weld

2-2-2. Ultrasonic Testing

In addition to radiographic testing manual ultrasonic testing has been executed. This test method is used to certainly discover non voluminous girth weld failures like cracks and/or bond failures. At repair areas the additional use of ultrasonic tests assures that previously objected failures have been completely eliminated and replaced by a high quality new weld.

Brand equipment Krautkraemer USK 7 and USK 8 have been utilized, which proved their value in this kind of extreme application by their traditional and very robust design as well as the quite temperature non-sensitive and contrast strong screen. The appropriate 60° and 70° angle probes as well originate from.

Krautkraemer. Paste with additive corrosion protection and if necessary antifreeze has been used as coupling.

Testing and evaluation standards API 1104 – Welding of Pipelines and Related Facilities, Edition 19, 1999 and ASME SE 164 – Standard Practice for Ultrasonic Contact Examination of Weldments have been required.

2-2-3. Additional Inspections

Based on inspections that have been performed during fabrication of preliminary products and pipes in the factory some additional inspections become necessary after pipe treatments like cuts or weld edge working.

UT lamination test

These inspections have been executed at hundreds of pipe ends according to API 5 L (Specification for Line Pipe, Forty-Second Edition, January, 2000) and ASME SA 338 (Standard Specification for Straight-Beam Ultrasonic Examination of Steel Plates) and no relevant laminations in that might affect the operational safety of the pipeline have been found in the pipe raw material.

Magnetic Particle Examination

If required, Magnetic Particle Examination black/white according to API 1104 (Welding of Pipelines and Related Facilities, Edition 19, 1999) and ASME SE 709 (Standard Guide for Magnetic Particle Examination) has been performed to assure that the surface of plate cutting edges and also welds are free of cracks.

3. The project figures

All following information only refer to operation of SGS Gottfeld NDT Services GmbH within Lot A at BTC Pipeline.

3-1. Project operation

Project budget:	US $ 4.25 Mio
Utilized personnel:	25 trained and certified inspectors from 6 nations concurrently working at 3 locations along the trace
Working time:	Total construction time 25 months, daily working time 10 to 14 hours, 6.5 days a week, 10 to 12 weeks journey home frequency, app. 75,000 performed working hours
Scope of work:	App. 25,000 radiographies, film consumption app. 75,000 m (5,250 sq m) AGFA D7 Rollback plus 2.5 tones of chemicals
Utilized Equipment:	6 X-Ray crawlers, 6 external tubes, 12 Ultrasonic devices, 4 darkroom containers with automated film development, 4 workshop and office containers . . .

3-2. Geography – Climate

Altitude:	Main camp Kars 1,740 m above sea level, highest point of pipeline 2,718 m above sea level, maximum altitude difference 1,115 m
Climate Zone:	Continental Climate Zone, average temperature 5,2°C, lowest and highest temperature during the project -37°C and +38°C, on average 580 mm rainfall per
Landscape:	Low to high mountains range with mainly agricultural areas, virtually treeless

3-3. Logistic

Accommodation:	3 central site camps with containers and sheds respectively, central lodging
Transport On-Site:	12 Pick-Up all-terrain vehicles with more than 800,000 km total mileage, while 60% of that Off-Road, fuel consumption app. 160,000 Liter
Material transport:	App. 70 tones of equipment and consumables in 8 containers transported from Germany by lorry
Travel connection:	Distance app. 3,000 km, flight connection Germany – Istanbul – Ankara – Kars, app. 5 flight hours with overnight stays

4. Conclusion

"Pipelines – for a changing society“ that means for pipeline construction in general and in particular for companies that perform non-destructive testing in this business, that projects have to be realized in a field and difficult to access areas, that adapting to local conditions and regulations as well as internationalization of project teams will stay daily business and that this will involve growing competition and constantly increasing demands on price, quality, equipment and personnel.

As traditional major German non-destructive testing company with experience of more than 15,000 km tested pipelines and the networking opportunities of SGS’s more than 42,000 employees in 1,000 offices SGS Gottfeld NDT Services GmbH will contribute to the safety of pipelines where ever and under whatever conditions they will be built to assure supply of Oil, Gas and other products in future.

¹Trond Gjedrem SGS Germany GmbH, Hamburg, Regional Director Industrial Services Central Europe, André Trostel, SGS Gottfeld NDT Services GmbH, Herne, Project Manager Pipeline NDT