Russian experience - Caspian Pipeline Nears Completion -

By Atbir, Daniel
Publication: Underground Construction
Date: Monday, January 1 2001

Over the 460-mile route, the pipeline crosses rivers, canals, roads and railways. Twenty-three conventional open cut main river crossings and 11 horizontal directionally drilled (HDD) crossings were executed by contractors working directly for the client.
Work is winding down on the long awaited Caspian Pipeline that will connect western Kazakhstan to the Russian Black Sea Port of Novorossiysk. The pipeline will allow maximum development of the Tenzig field, which potentially holds six to nine million barrels of recoverable oil reserves.
The CPC that will ultimately own and operate the 460-mile pipeline is comprised of the following private and government entities: Government of Russian Federation, Republic of Kazakhstan, Sultanate of Oman and Chevron Caspian Pipeline Consortium Company (USA); Lukarco B.V., Rosneft-Shell Caspian Ventures Ltd., Mobil Caspian Pipeline Company (USA), Agip International, BG Overseas Holdings Ltd., Kazakhstan Pipeline Ventures L.L.C., and Oryx Caspian Pipeline L.L.C.

In addition to the new pipeline, the CPC currently has a 518-mile pipeline that originates in Tengiz, Kazakhstan, and is routed around the northern end of the Caspian Sea, terminating at Komsomolsk, Russia. The new 460-mile pipeline will extend from Komsomolsk to the new terminal shore facility being built northwest of the Port of Novorossiysk, on the Black Sea. Once completed, the pipeline will traverse approximately 981 miles of Kazakhstan and Russian terrain, and will be the primary export facility for Kazakhstan oil to the west.
SSP-Starstroi, a French-Russian consortium sponsored by Bouygues Offshore, Bouygues Group and Spie-Capag, was awarded a contract valued at $271 million to construct the 460-mile Caspian Pipeline and upgrade and refurbish 180-miles of CPC's existing 40-inch diameter pipeline between the Russian-Kazakhstan border and Komsomolskaya.
Russian pipeline contractors played a significant role in constructing the new pipeline. VolgogradNeftegazStroi (VNGS) performed rehabilitation works and constructed the eastern portion of the pipeline located in the Republic of Kalmykia; StavropolTruboProvodStroi (STPS) and SvarochnoMontajniTrust (SMT) shared responsibility for the work in the region of Stavropol; KubanNeftegazStroi (KNGS) constructed the pipeline in Kuban territory of Krasnodar Krai, while VostokNefteProvodStroi (VNPS) completed the section leading to the export facilities in Novorossiysk. Work on the project began in October 1999 and was on target for mechanical completion late last year.

Landscape
Over the course of the route, the pipeline crosses four regions of different landscapes, from East to West, i.e., Astrakhan Oblast, Republic of Kalmykia, Stavropol Krai and Krasnodar Krai. The two eastern regions are located in the Caspian Coastal Depression with flat plain, gently sloped undulating plain and Saiga antelope calving areas. Ground cover is described as sparse to denuded grass areas with few to no trees. The surface characteristics for Stavropol Upland are described as valley-ravine dissections and deep depressions with a ground cover of cultivated fields. Krasnodar Krai consists of irrigated land, rice fields and mountainous areas.

Contract Scheme
To meet a tight construction schedule and maximize local content, new construction was divided into four spreads and constructed simultaneously. On Spread No. 1, VNGS installed 150 miles of 40-inch Russian manufactured API 5L-X65 line pipe. On Spread No. 2, SNT was charged with constructing 152 miles of mainline construction. Spread No. 3, that involved the construction of 17 miles of 40-inch and 90 miles of 42-inch diameter pipe, was handled by KNGS, while VNPS completed work on Spread No. 4 that required 71.4 miles of 42-inch diameter mainline construction in both rice fields and in the mountains.
Each contractor handled all construction related activities on their respective spreads including ROW clearing and grading, trenching, double jointing, stringing, welding, coating, non-destructive examination, lowering in, ballasting, backfilling, road, railway and water crossings, hydrotesting, cathodic protection and mainline block valves and scraper/launcher installation.

ROW and Trenching
Initially, the client obtained Final Land Allocation of the ROW that ranged anywhere from 46 to 98.4 feet wide. Even though ROW acquisition was a vital component, emphasis was also placed on ensuring that topsoil could be returned to its original location. In total, more than 2,500,000 m3 (88,286,188 cubic yards) of topsoil was carefully and meticulously separated to preserve the quality of upper layers of fertile ground.

A trench 6.5 feet wide and 6.5 feet deep was excavated throughout the first three spreads using trenching machines for the linear part and backhoes at crossing locations. It seems worth noting that backhoe trenching was not possible on Spread No. 4, where crews encountered hard rock in the mountain area that forced the contractor to rely on drilling and blasting measures to excavate the rock and achieve the required trench size.
Trees were also plentiful over the course of the route. More than 22 miles of trees situated in the ROW were removed. Once felled, trunks and logs were given to farmers for domestic use while stubs were buried in designated quarries authorized by the regional Krai.

Pipe Transportation
The project has overcome many difficulties with regard to pipe transportation, including limited road networks, mobilization during inclement weather, and construction activities starting simultaneously on many fronts. On average, 55 miles of pipe per month was moved during 8,200 truck trips and 6,000 trips by rail.

Double Jointing
To keep field welding activities reduced as much as possible, a total of 12 pipe yards were installed and fully equipped by the contractor to make it possible to weld up pipe joints with an average length of 72 feet that could be transported distances of up to 37.2 miles from the ROW.

As to welding, two processes were used to perform the 30,200 welds; complete SAW (Submerged Automatic Welding) with two to three passes and a combination of SAW and SMAW (Submerged Manual Arc Welding) with back weld up to three passes.
Welding

Pipe wall thickness ranged from 10.6 to 15.3 for 40-inch API 5L - X65 and 10.7 to 14.7 for 42-inch API 5L - X70, with the heavier wall pipe used at special crossing locations. A great deal of flexibility was given by the various welding procedures developed and approved by the Russian control organizations (Gosgortechnadzor and VNIIST). Three major welding processes were used; SMAW, a combination of SMAW and FCAW (Flux Core Arc Welding) also called inner shield, and GMAW. With the latter being a particular source of pride, since three complete CRC-Evans automatic welding spreads were brought in from the U.S. for the purpose of training crews. Later, a high output was achieved, together with good standard of quality in a very short time. More than 65 percent of all girth welds were performed using GMAW. X-ray radiographic examination was used on all welds, and a repair rate approaching five percent was achieved and continuously improved.
Coating

Shrink sleeves of 430 mm wide and 4 mm thick were used to bond welds after being inspected. These were used on both FBE (Fusion Bonded Epoxy) and PE (Polyethylene) coated pipe. In addition, at intervals along the pipeline, sacrificial anodes were installed to protect the pipe against corrosion during the construction phase and anode beds installed to support the voltage in the cathodic protection system.
Crossings

Over the 460-mile route, the pipeline crosses rivers, canals, roads and railways. Twenty-three conventional open cut main river crossings and 11 horizontal directionally drilled (HDD) crossings were executed by contractors working directly for the client. In addition to the main river crossings, the route crossed 250 canals, the majority of which are located in the territory of Krasnodar. Set-on weights, concrete slabs and bolt-on weights were installed at waterway crossings as anti-buoyancy measures. Road crossings on the project were made through open cut or bored methods of construction. The bored crossings were installed inside corrosion-coated casing pipes. Similarly, all railway crossings on the project were accomplished through boring.
Construction Challenges

From a construction point of view, the main challenges for contractors occurred as crews moved west. In Kalmykia, where terrain is relatively flat, the main challenges were the extreme weather conditions. In addition, several major river crossings were required, and the introduction of microtunnelling was needed for the Chernozemelsky Canal crossing at KM 101, as conventional open cut and boring methods were not suitable. In the Stavropol region, the contractor relied on microtunnelling for the Pravo-Egorlyksky Canal crossing at KM 339. Also, two commercial fish farms in Stavropol Krai had to be drained. The challenges on Spreads 2 and 3 proved similar and primarily involved elevation changes. One of the more significant construction challenges came on Spread 4, which although only 71.4 miles in length, required the crossing of rice paddies, mountainous terrain and approximately 170 crossings of various types. The construction techniques used on Spread 4 differed considerably from the other spreads, due to the nature of the obstacles and difficulty of the terrain.
Environmental and Safety

An environmental management program has been developed with the client to prevent, mitigate, respond to and remedy the impact of construction operations on key environmental components (air, water, soil, vegetation, wildlife) as well as health and livelihood of all the people involved on the project.
Social Economics

The execution of this project has been welcomed in the various regions and has provided hundreds of jobs for locals. The project has also provided work to many local suppliers and will obviously benefit the economies of the regions in which the pipeline was constructed.