INNOVATIVE SOLUTIONS APPLIED TO CONSTRUCTION OF THE BLUE STREAM GAS PIPELINE A.S. Fyodorov, Gazprom A.G. Ananenkov, V.E. Bryanskih, B.V. Budzulyak, V.I. Rezunenko, Gazprom A.V. Sergienko, Giprospetsgaz Under the conditions of market relations and total informatization of our life a speed of companyreacting to changes in pricing or political situation largely depends on the implementation of the achievements of scientific and technical progress and wider use of modern high technologies both in the projects designed and for improvement of the design process itself. 3D-model of the sea bed relief The Blue Stream transcontinental system of gas transportation is characterized by complex logistics, difficulties in construction and operation of the deep-water trunk gas pipelines, higher ecological requirements as well as greater influence on the system of effects of non-technical character. Innovative character of the project stipulated system approaches to decision taking at early stages of the project and that allowed to carry out optimization of Blue Stream from the gas field to the consumer and coordinate the terms of its implementation, operation modes and parameters of its various components and provide for the necessary level of redundancy and thus to increase reliability and safety. The construction of the high technology gas pipeline required the consolidation of efforts of engineering companies of Russia, Italy, the Netherlands, USA, France, Norway, Japan and other countries. Blue Stream gave a powerful impetus to the development of the world gas industry and thus justified the leading positions of Russia as a major gas supplier. Among the vast number of new ideas implemented in the project there are some ones attracting special attention. These are: Innovatory standard and code basis. Equipment for engineer survey at the offshore section. Pipe-laying complex at the offshore section. Cascade gas compression with super-high pressure on the Russian side. Technologies of gas high dehydration. Beregovaya CS with record design parameters. Wide use of directional drilling while constructing underwater crossings on the Russian side. Microtunnelling. Application of modern information technologies. System of industrial and ecological monitoring.
From DNV-96 rules to DNV OS-F101 standard To obtain an international certificate Blue Stream from the very beginning has been designed on the basis of DNV-96 rules for submarine pipeline systems. At the stage of the basic design the experts of Det Norske Veritas performed the expert follow-up of the project and certification work from geotechnical analysis to verification of hydraulic analysis, selection of coating and risk analysis. The realization of the gas pipeline, record by its parameters, even at a stage of engineer survey enabled to exceed the international achievements in this field. Five research ships from three countries were involved in survey of the offshore section. The results of this work allowed for DNV to develop new codes and methodology approaches to the design, verification and certification of the offshore pipelines. They differ from the Russian code basis in the target to provide for the quality of the whole work cycle of pipeline construction versus strict regulation of parameters and directive prescription of technologies to be applied restricting the creative approach of designers to the solutions adopted. The code specifies the requirements for different levels of design risks with a possibility to define in detail both a required scope of work and degree of its influence on the project for every level. New methodology is implemented in the DNV OS-F101 standard for offshore pipelines issued in 2000 and covering all aspects of pipeline engineering, including insurance of procurement. The standard gives unified criteria and represents guiding material for all stages of a life cycle of the project including survey, design, construction and operation, up to liquidation of the worked out system. Implementation of standard in Russia enables to have unified requirements to provide for the safety of submarine pipeline systems and creates a basis for civilized contract relations for all participants of project implementation. Vessel Akademik Golitsyn
Research Gazflot ship Akademik Golitsyn, built especially for the Blue Stream project, was used for control of pipeline laying with ability to carry out the whole cycle of research work for deepsea offshore pipelines, including: survey of submarine cable routes, sites for platform installation and construction of hydraulic facilities, in the arctic areas included, control of pipe-laying process, inspection of pipe status during operation, some types of repairs (coating repair, anode replacement, etc). The characteristic features of the vessel are extremely high installed power, high-performance system of dynamic positioning, precision systems of underwater and satellite navigation, powerful computing complex aboard, high stability. The portfolio of contracts testifies to the fact that a unique vessel has been built which is demanded by the world market. This enables Gazprom to occupy active positions in the matter of gas pipeline maintenance and serves as an important element of technical policy of Gazprom in realization of new offshore projects. A few words about a unique offshore pipe-laying complex. SAIPEM 7000 in Rotterdam harbor The following companies are the world leaders in the sphere of pipe-laying at sea: Mc Dermott, USA; ETPM, France; Saipem, Italy; Rockwater, Great Britain; Heerema Group, the Netherlands; Allseas, the Netherlands. Unlike onshore pipelines, a submarine pipeline is subjected in the process of laying to linear and angular displacement caused by wind, waving and current. Therefore, a pipeline is in a stressed and strained status characterized with tension, bend and vibration loads. As it is accepted in the world practice, the laying of pipelines with D u 910 mm by S-method is generally carried out at a depth of 300-350 m, with D u 1220 mm and more at a depth up to 200 m. At greater depths (600-800 m and more) a J-method is used or its modification a vertical laying. The J- method is considered to be more reliable and the S-method provides for greater speed of laying.
SAIPEM 7000 en route At an early stage of Blue Stream tender preparations and bid analysis the optimization of all parameters was carried out based on criteria of resistance to the loads applied in order to determine the limits of the sea status parameters leading to idle time of the pipe-laying complex. The analysis testified to the fact that the best results had been reached while using combination of different methods and that had been done for the Blue Stream project. Pipeline laying was carried out by the S-method in shelf zone and partly in upper sections of the Russian and Turkish slopes by The Castoro Otto pipe-laying vessel and in deep-sea section by J-method with the S7000 pipe-layer. The connection zone was at a depth of about 300 m. One of the most significant innovatory solutions of the designers is a process layout of the gas pipeline with a cascade compression scheme and increase of operation pressure from 7.5 MPa to 10 MPa at section Krasnodarskaya CS Beregovaya CS and to 25.1 MPa at the offshore section while simultaneously decreasing pipeline D u and increasing number of lines. Gas pipeline transportation scheme
The results of the latest studies conducted by the design institutes in the sphere of distant gas transportation by experience of such gas pipelines as Yamal-Europe, Blue Stream and Teriberka- Volkhov demonstrated economic advantages of use of high operation pressure and increased degree of compression with increased CS spacing. Use of operation pressure of 8.3 MPa, 10 MPa, 12 MPa and more of that 25.1 MPa (Beregovaya CS) allows for new possibilities in the optimization analysis. Unfortunately, the state standard basis is still lagging behind. A number of new codes is required including construction code (SniP Trunk gas pipelines ) with operation pressure up to 30 MPa. Exchange of experience with TransCanada and Snamprogetti companies indicated that they were also actively engaged in the studies in the field of higher operation pressure. There are advanced methods of analysis and valuable experience of implementation of high-strength steel and welding and assembly procedures which are planned to implement in new Gazprom projects after detail discussion and adapting to the Russian codes. Such solutions are of special importance for the Yamal project and for gas transportation system to the countries of Asian and Pacific regions. Gas treatment plant at Krasnodarskaya CS The key task, which provides for reliable and uninterrupted gas delivery at the submarine section of the gas pipeline, is to achieve one-phase gas transportation i.e. without liquid phase water, hydrocarbons and hydrates. Complex of research work and marketing measures became a basis for an optimal selection of method to prepare gas for transportation which allowed to choose the most modern, economical and reliable technology. The scientific analysis of thermodynamic gas parameters in the submarine section of the gas pipeline with regard for various options of gas composition and of contract requirements to gas parameters on the Turkish side demonstrated that the temperature mode was greatly influenced by the spatial configuration of gas pipeline and heat exchange with the environment depending on the pipeline deepening into the bottom ground. The singularity of design shall be noted on combination of hydraulic analysis program with geo-information system enabling to carry out optimization of hydraulic and temperature modes of the pipeline with respect to spatial parameters and ground conditions.
Adsorber assembly for gas treatment plant Technical and economic analysis of options demonstrated an advantage of the adsorber technology combining high degree of gas dewatering and extraction of heavy hydrocarbon. Beregovaya CS is one more unique object. Composition, location and layout of CS process plants present an example of the whole range of non-traditional design solutions stipulated by the site location in mountain area and resort zone. There are some of them: 3D-model of Beregovaya CS
Beregovaya CS is located on the pipe. The 20 th valve is mounted within the site fence. gas compression system comprising six gas compression units with capacity of 27 MW each with separate gas air coolers and additional outlet filter-separators to provide for greater degree of flexibility while changing operation modes. safety units are designed and included in the piping to prevent from pressure excess. More stricter requirements of the international codes are accepted in the calculations. They start operation while reaching 95% of the operation pressure when national codes allow for 105%. Tunnel crossing through the Kobyla ridge Complex of new high technology processes was also used during design and construction of the onshore section of the pipeline. We think we shall listen to detail reports about the directional drilling method having a number of advantages over traditional trench method, about microtunnelling, reinforcing slopes with geoweb mesh and other innovations. When effective national plants for directional drilling are not available, at present most of the crossings are constructed with the machines imported. Analysis of the international experience of construction and operation of the gas pipelines and particularly offshore ones demonstrates that implementation of modern information technologies for management of the technical information at all stages of design, construction and operation of gas pipelines provides for succession of the decisions taken at various stages of realization of the investment project, allows to reduce technical risks and avoid great operation costs.
Standard window of the information system The unified information medium for effective integration of all data relating to the pipeline and for decision taking is provided by the use of geo-information technologies (GIS-technologies). The world practice of construction contemplates an issue of documentation as built after construction and assembly work. The documentation is stored with the legal owner of the object during the whole life cycle and is actualized during repairs, equipment replacement, expansion and modernization. By present the collection of production executive information in electronic format directly in the lines of construction is realized as well as high accuracy geodetic positioning of weld joints and SDVvalves of the pipeline, input of the initial data into the Open standard data model of the pipeline system. DEAR COLLEAGUES! One can find new technologies and equipment practically in every section of the Blue Stream project but in the long run, we are sure, the present innovations will be common practice in the world gas industry and in the shortest time will be implemented in our great initiatives such as YAMAL and EAST SIBERIA.