TECHNICAL CONCEPT OF THE INTEGRATED SHTOKMAN FIELD DEVELOPMENT

Alexander Piotrovskiy JSC Giprospetsgaz St.Petersburg,

The Shtokman field, liquefied (LNG), trunkline, LNG sea transportation.

The interest towards the development of the Shtokman gas and condensate field has been growing lately which is quite explainable and understandable in connection with its coming development. The integrated development of the Shtokman field is planned to be implemented in three phases. The target market of the (LNG) from the Shtokman field are consumers in the USA and Europe. The supplies of the natural gas will also be provided to the common gas transmission system as well as to consumers in the North-Western region of Russia. Together with the implementation of the Shtokman field development project the favourable conditions will be developed for development of the entire complex of industrial and social (technological and social) infrastructure, which has strategic and geopolitical significance. In northern and north-western regions of the Russia Federation it will allow developing the economics more effectively with high social potential and responsibility. The raw materials base of the integrated development of the Shtokman gas and condensate field is located in the central part of the , 650 km north-eastwards off Murmansk, 920 km north- eastwards off Archangelsk and 290 km westwards off Novaja Zemlya island. The gas reserves of the Shtokman gas and condensate field are estimated to more than 3.7 billion m 3. The implementation of the first phase of the Shtokman field development provides for transportation to shore of approximately 23 milliard m3/year of gas for the production of LNG and supplies to Murmansk- Volkhov trunkline to St. Petersburg area. The overall production provided for the three phases is more than 71 milliard m 3 gas per year. The period of continuous gas production is approximately 24 years and the designed field operation period is 50 years. Remoteness of the field from the shore, arctic ice and metocean conditions cause a row of technical and economic challenges, which are impossible to be solved without novel technical solutions. For the justification of the choice of the option for the Shtokman field development a wide scope of technical solutions has been considered:  on field development options;  transportation of gas from field to onshore facilities including options of single-phase, two-phase and multi-phase transportation;  various options of gas liquefaction and means of sea transportation of LNG The technical concept of the integrated development of the Shtokman gas and condensate field provides for the development of an integrated complex comprising of (Image 1): • subsea production systems; • offshore ice-resistant process platforms; • system of offshore pipelines; • port transportation technological complex (PTTC), including the LNG plant, the gas treatment unit and a specialized sea port; • offshore operations support base; • Murmansk-Volkhov gas trunkline; • LNG vessel transportation. One of the key elements for the field development is the application of subsea technologies with the systems of subsea completion of wells located on the sea bed. The newest technologies of field production of the natural gas suggested in the technical concept provide for systems of subsea wells development, 2 equipped with assembly, automatically regulated butterfly valves, hydrate inhibitor injection systems. The equipment is laid out on templates. The wells are jointed by subsea pipelines and manifolds. The project provides for construction of subsea production system consisting of 17 integrated complexes (templates and manifolds) for 4 wells each and 3 platforms (one for each phase), which will be used for compression and preliminary treatment of gas for pipeline transportation.

Subsea Production Unit Turret with swivel Production FPU-type System

LNG Transportation

Offshore

Pipeline 2х36 ” two-phase transportation

Well

Gas Treatment Trunkline Unit LNG Plant

Image 1. Technical Concept of the SGCF Integrated Development

At the pre-design stage several options of production units have been considered – types TLP, SPAR, BUY, FPU, FPSO. And if at the initial state the preference was given to SPAR-type platform, after more detailed studies of metocean and ice environment as well as basin tests, the vessel-type platform (FPU) was selected (Image 2).

Image 2. Offshore Ice-Resistant Production Platform of Vessel-type (FPU) 3

For the transportation of formation fluid, consisting of natural gas and condensate from the field to shore a subsea pipeline more than 540 km long has to be constructed. The profile of gas pipeline route has significant elevation differences and maximum depth of about 350 m. There have been no projects implemented for subsea transportation of two-phase flow for such long distances. However, contemporary research methods and newest technologies of gas subsea transportation management show principal technical possibility to implement the concept of two-phase gas transportation. It is planned to build three subsea trunklines from the Shtokman field to Opasova Bay () in order to implement the two-phase transportation of gas to shore. The integrated development of the Shtokman field includes also the Murmansk-Volkhov gas pipeline supplying the gas from the Shtokman field to Russian the common gas transmission system. The overall route length is over 1300 km. It crosses three constituent territories of the Russian Federation, 15 districts; more than 450 water bodies, 12 of them are more than 200 m wide; over 200 km of rocky areas; 235 km of marshes; 16 passes over railways and 76 passes over motorways. The route lies in badlands. On the first and the second stages of field development the concept provides for construction of facilities for the production of liquefied natural gas. The project provides for construction of Port Transportation Technological Complex (PTTC) as part of the LNG Plant, LNG Storage, Specialized Sea Port and Gas Treatment Unit for surface transport. The site will accommodate production, loading, administrative, port and auxiliary complexes. Construction of a complex for production of liquefied natural gas is planned in the area of Teriberka settlement of the Murmansk Region. The Liquefied Natural Gas Plant (hereinafter referred to as the LNG Plant) is the main structural element of the Port Transportation Technological Complex (PTTC) which is planned to be constructed in three stages: Plant Start-Up Complex (Phase 1) and its further expansion on Phases 2 and 3 (Image 3).

The LNG Plant

Main Units of LNG Plant LNG Storage to GTU Acid Gas Dehydration Mercury Removal Removal Liquefaction Unit LNG for sea shipping Process to fuel gas preparation Cooling LNG LNG system System Storage Delivery Unit

Receiver and Natural gas Slug Catcher Gas Metering from offshore Unit trunkline Atm. Fractionation and Separation of Natural Gas Liquids for start-up I N2 Removal Mixed Cooling Medium System Condensate for Condensate sea shipping Stabilization Condensate Condensate Unit Storage Delivery Unit

Atm. Auxiliary Units of the LNG Plant Management and Maintenance

Water Heating Medium Power Generation Acid Gas Incineration Unit Cooling Medium Preparation Preparation Fuel Gas Unit Storage Central Maintenance Treatment System System Control Room Buildings

Air Unit Flare System Emergency Power Instrumentation and Chemical Storage Sewage Treatment Station Fittings Facilities

Inactive Gas Unit Diesel Storage Fire Water Supply (Nitrogen)

Image 3. Structural Scheme of the LNG Plant On the first phase of the Shtokman GCF development it is planned to construct one processing train for natural gas liquefaction based on technology of Propane Pre-cooled Mixed Refrigerant Cycle (C3/MR) of American company Air Products and Chemicals with tank farm for liquefied natural gas storage and offloading system. The efficiency of the processing train for natural gas liquefaction is 7.5 million tons per year. 4 The storage of LNG is planned to be provided in insulated storage tanks. The storage system includes six tanks with capacity of 160 thousand m 3 each, which operate at pressure of 30-45 mbarg and temperature 162 °C below zero. At that LNG storage during the first phase is going to be provided in 2 tanks with overall capacity of 320 thousand m 3. The following sequence of processing operations at processing units is carried out for liquefaction of natural gas: • primary treatment of two-phase flow in feed gas receiver, the main unit of which is the slug catcher; • removal of acid gas out of feed gas; • dehydration of feed gas; • removal of mercury out of feed gas; • separation of natural gas liquids and aromatic hydrocarbons; • liquefaction of natural gas; • removal of nitrogen out of liquefied gas; • fractionation of С2+ hydrocarbons mixture with separation of components of mixed cooling medium and natural gas liquids; • stabilization of hydrocarbon condensate, storage of stabilized condensate and its delivery to jetties for further loading on tankers; • LNG storage and its delivery to jetties for its further loading to gas carriers. • removal of stripping gas. It is planned to use atmospheric air at ambient temperature as the main cooling medium. The driving unit of main cooling compressors for liquefaction is the electric drive with regulated speed of rotation. In order to assure operating parameters of the process of the LNG Plant units it is planned to use special heating medium as a high-temperature heating medium which will be heated by the exhaust of gas- driven turbines of the heat power station. The power generation unit is planned to be of gas-stream cycle with duty over 600 megawatt. The processing units of the LNG plant will be operated not less than 333 days a year. The operation period of the LNG plant is 50 years. In order to deliver gas to surface trunkline Murmansk – Volkhov the Gas Treatment Unit (GTU) is planned to be installed. The GTU serves to transform the properties of gas and lower the temperatures of water and hydrocarbon dew points to meet the requirements of the Russian standards and includes: • gas dehydration; • extraction of condensable hydrocarbons out of part of gas. The Sea Port is used for loading the liquefied natural gas to gas carriers. Besides, the port jetty is used for loading the stable condensate and receipt of materials to be used in the process (diesel fuel, cooling media, chemicals et cetera).

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Image 4. LNG Plant Location

In order to deliver the LNG to the sale market several route options for LNG supplies to terminals in the USA and Europe have been studied. Taking into consideration the distance to receiving terminals, volume of supplies, speed of vessels and other parameters, the number and sizing of gas carriers was optimized. All in all over 20 vessels with capacity up to 165-195 thousand m 3 will be needed. The accepted technological solutions and environmental activities assure the technical and environmental safety in full and minimize the environmental impact. Extraction of natural resources for the gas transmission system facilities excludes significant loss of natural resources potential of the considered areas. Development of the hydrocarbons reserves of the Shtokman gas and condensate field onshore, and mainly on the continental shelf will provide an opportunity to establish a new resource base for Russian gas industry and regional base for gas supplies to domestic and international consumers. The north-western economy will get new strategic objectives – investments into economy and industry, construction, utilities, tax returns, establishment of working places, sustainable energy resources supply. The extracted natural gas resources will be used to gasify the regions of Russia which will certainly improve their welfare and improve the quality of life of their population.