5.7 Export Pipelines 5.7.1 Overview Phase 3 offshore facilities will use the existing Azeri Project marine export pipeline infrastructure to export its oil and gas to the onshore terminal at Sangachal. This existing pipeline infrastructure includes: A 30 diameter oil pipeline running from the Central Azeri field to shore installed as part of the Phase 1 project; A 28 diameter gas pipeline running from the Central Azeri field to shore installed as part of the Phase 1 project; and A 30 diameter oil pipeline running from the Central Azeri field to shore to be installed as part of the Phase 2 project. There is also a 24 oil line from the EOP Chirag-1 platform to shore but this facility will not be used as part of the Phase 3 development. To enable Phase 3 oil and gas to be exported, three (3) infield export pipelines will be installed between the Phase 3 PCWU platform and the above Azeri Project pipelines. These pipelines will be connected to the existing pipelines at connections (wye pieces) pre-installed on the Azeri Project pipelines. Details of the Phase 3 export pipelines are presented in Table 5.17. Table 5.17 Phase 3 Infield Export Pipelines From To Service Outside Diameter (inches) Length (km) PCWU Subsea Wye at circa KP 22 on the Phase 2 30 pipeline Oil 30 2.4 PCWU Subsea Wye at circa KP 22on the Phase 1 30 pipeline Oil 30 2.2 PCWU Subsea Wye at circa KP 22 on the Phase 1 28 pipeline Gas 28 2.0 5.7.2 Design The Phase 3 export pipeline materials and design will be consistent with that used for the Azeri Project. The pipelines will be constructed of carbon steel (SAW Pipe Grade X65) and will be designed to ensure that they are suitable for the environmental conditions in the development area including seawater properties and geo-hazards. All the pipelines will be fitted with non-return check valves near base of the PCWU platform. The pipelines shall have external corrosion protection that will consist of a three-layer polypropylene/polyethylene coating. Additional external corrosion protection will be provided through cathodic protection by means of conventional aluminium-zinc-indium sacrificial anodes attached to the pipelines at regular intervals. The pipelines will also be externally coated with concrete or steel to provide the weight required to ensure stability on the seabed as well as mechanical protection against impact. 5.7.2.1 Proposed Route and Crossings The Phase 3 export pipelines will run from the PCWU platform in a northerly direction towards the existing Azeri Project pipeline corridor where they will connect into pre-installed subsea pipeline wyes as illustrated in Figure 5.26. 31648-046 ACG Phase 3 ESIA Chapter 5 5/59
Figure 5.26 Phase 3 Export Pipeline Connections to Azeri Project Pipelines TO SANGACHAL 28 GAS (Phase 2) (Phase 1) 28 GAS 24 OIL 28 GAS 2 * 16 GAS TO OIL ROCKS 24 OIL 18 GAS 22 GAS 18 WATER INJ 14 PROD WATER North Flank WI Manifold PCWU DUQ CHIRAG 1 WA-PDQ 6 GAS LIFT CA-CWP CA-PDQ EA-PDQ 2 * 14 Water Inj Lines P3 - DEEP WATER GUNASHLI South Flank WI Manifold 6 GAS 14 PROD WATER 16 WATER INJ 16 WATER INJ 22 GAS NOTES : = 2 ball valves, I.e. double block & bleed. Subsea Pipeline Check Valves not shown on this schematic, for clarity. Fibre Optic Cables, Power Cables and Umbilicals not shown on this schematic, for clarity. The pipeline routes have been selected to optimise line spacing and to minimise lay-barge anchor pattern interference and risk of damage to existing lines due to dropped objects. The pipelines will need to cross existing pipelines on route to the connection wyes of the main export pipelines. Crossing structures (e.g. concrete on steel support) will be placed along the flanks of the existing pipelines and underneath the Phase 3 pipelines so that sufficient spacing between the individual lines is provided. The separation will ensure no mechanical or cathodic protection interaction occurs between the lines. Further information can be found in the Phase 1 ESIA, Section 5.6.4. 5.7.3 Fabrication Carbon steel pipeline sections will be manufactured outside Azerbaijan: most likely in Japan or possible Europe. The pipe sections will be transported to the Caspian via the canal system or by road or rail. It is planned that the pipes receive the application of corrosion protection and concrete coating in Azerbaijan. 5.7.4 Installation The pipe-lay barge Israfil Guseinov will be used for the Phase 3 project. It was upgraded for the Azeri Project pipeline installation programme so that it could handle that project s 30" and 28 pipelines. The upgrade included works on the pipe roller, tensioners and accommodation facilities as well as a general equipment overhaul and upgrade. No further upgrade work is required for the Phase 3 Project export pipeline installation programme. Criteria for clearances of existing pipelines and safe methods of pipeline construction will be evaluated and defined prior to commencement of the Phase 3 pipeline installation programme. The installation methodology will be consistent with that applied for the Azeri Project. It is anticipated that the installation programme for the three export pipelines will be completed within a 50-day period. On the lay-barge, each pipe section will be welded to the preceding one and the weld joints will be visually inspected and integrity tested using NDT techniques. The weld area will then be field-coated for protection with anti-corrosion material. The pipeline will be progressively 31648-046 ACG Phase 3 ESIA Chapter 5 5/60
deployed from the stern of the lay-barge via the stinger, a support boom that extends out the stern of the barge. Deployment will be from the platform out towards the pre-installed wye pieces on the Azeri project pipelines, and will be aided by a tensioning system that maintains a constant deployment rate and thus reduces the risk of bending stresses being incurred. The pipe-laying operation is continuous with the barge moving progressively forward as sections of the pipe are welded, inspected, coated on board, and then deployed to the seabed. The barge is held in position by anchors.as pipe-laying proceeds, the anchors are periodically moved by two anchor handling tugs to pull the barge forward (with one more on standby). The distance of this varies but is typically every 500 m to 600 m of pipeline length. The lateral anchor spread of the pipe-lay barge is typically between 600 m to 700 m either side of the pipeline. Once in place, the line will be flooded with inhibited seawater in preparation for commissioning (Section 5.7.5) and then tied-in to the wyes and spools at the platform. 5.7.4.1 Support Vessels A number of vessels will support the pipeline installation activities. Pipe-haul vessels will transport pipe sections from the pipe storage yard to the installation site. Some of these vessels will also collect wastes including sewage sludge generated onboard the pipe-lay barge and will transport these to shore for treatment and disposal. The number of attendant vessels and anticipated persons on board (POB) these vessels during the installation programme are presented in Table 5.18. Table 5.18 Pipe-Lay Support Vessels Vessel and Description Number POB Lay-barge: 1 210 Anchor handling vessels: 2-3 15 Pipe-haul barges and tugs: 3 14 Power generation onboard the pipeline lay-barge will be provided by five diesel generators rated at 1,150 kw each. The other support vessels will also have diesel generator for power supply. As for the Azeri project, vessels proposed for use in the installation programme will be equipped with a USCG certified (or equivalent as per PSA) sewage system. Water from showers, sinks and laundry (grey water) will be discharged directly overboard without treatment although it may be possible to divert it to the sewage treatment plant if required. The final sewage effluent will be treated to a BOD of 40 mg/l, suspended solids 40 mg/l and coliform 200 MPN per 100 ml prior to discharge. Sewage sludge from operational vessels will be transported to shore on board the pipe haul barges to a designated reception facility. There are three main vessel drainage routes, accompanied by manual/mechanical clean up where appropriate: Discharge to sea (clean water only); To the oily bilge water tank for treatment and discharge of the treated effluent to the sea and transport of the sludge onshore; and To the waste oil tank. Galley food waste will be treated in a macerator prior to discharge to meet specifications of the MARPOL 73/78 Annex IV Regulations for the Prevention of Pollution by Garbage from Ships which requires that the waste be broken down into particles of less than 25 mm diameter. 31648-046 ACG Phase 3 ESIA Chapter 5 5/61
5.7.5 Commissioning Once installed on the seabed, the export pipelines will be gauged and hydrotested (integrity leak tests). The pipelines will be flooded with seawater dosed with biocide and oxygen scavenger, and pressure will be supplied to the pipeline from the platforms. On completion of hydrotesting the pipelines will be tied into the connector wyes and platform and subsequently dewatered. The dewatering process will be different for the oil and gas lines as follows: Oil pipelines: A pig will be launched from the platform with the oil. The pig will be driven into the Phase 1 and 2 pipelines where it will continue on to the terminal. At the terminal, the hydrotest water will be removed in the onshore oil separation and stabilisation process trains, and the recovered hydrotest water will be disposed of through the produced water disposal system. Gas pipeline: A pig will be launched from the platform. A glycol slug will be injected behind the pig and in front of the flowed export gas. The hydrotest water will be discharged to sea at the connector wye on the Azeri gas pipeline via a 4 valve. The gas will then be allowed to flow into the Phase 1 and 2 gas pipelines and onto the onshore terminal. 5.7.6 Operation and Maintenance Each of the Phase 3 oil pipelines will be pigged on a regular basis, predicted to be every 3 days. The pipelines will be designed to be capable of being pigged by the following types of pigs: Foam Pigs (installation phase); Batching pig; Scrapers; and Intelligent pigs. Pigging will be from offshore to onshore. Based on data from the EOP Chirag-1 24 oil pipeline that generates ~200 kg of wax and sand per pigging run, it is estimated that the 30 Phase 3 pipeline lines, including the section from the connector wye to the shore, will generate 1 tonne of wax and sand per pigging run. This equates to approximately 250 tonnes per year from both pipelines. Any wax and sand removed will be disposed in accordance with the AzBU Waste Management Strategy and ACG Project Waste Management Plan. Leak detection in the pipelines will be achieved by monitoring pipeline pressure and export volumes. The pipeline will also be intermittently surveyed using a ROV to check for unacceptable freespans under the pipeline and that no damage to the external coating has been sustained. Supply vessels and helicopters will travel the pipeline route on routine journeys as an additional leak detection measure. 5.7.7 Other Subsea Cables A new fibre optic cable will be installed from the Phase 3 DUQ to the Central Azeri PDQ Platform for connection to the WAN system installed by the Azeri Project. The Azeri Project will have pre-installed a cable end on the Central Azeri PDQ platform for this Phase 3 connection. Installation of the subsea communication cables on the seabed will likely be completed by the DSV Tofiq Ismailov supported by a ROV. However, other suitable vessels such as an anchor handling tug may be used; the choice of vessel will depend on the vessel schedules closer to installation time. 31648-046 ACG Phase 3 ESIA Chapter 5 5/62
5.7.8 Subsea Pipeline Wastes, Emissions and Discharges In-country emissions, discharges and wastes generated during pipeline coating, installation, commissioning and operation will primarily result from power generation at the pipe coating yard and operation of the pipe-lay and support vessels, in addition to the discharge of hydrotest water. 31648-046 ACG Phase 3 ESIA Chapter 5 5/63
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