ANSI API RP 17A:2006 pdf download
ANSI API RP 17A:2006 pdf download.Design and Operation of Subsea Production Systems-General
Requirements and Recommendations.
— commissioning requirements.
In addition, a strategy on flow assurance for the development should be established. Various subjects on flow
assurance to consider are discussed in Annex I.
5.3.2 Simultaneous operations
The potential for simultaneous operations during installation and/or intervention should be assessed. Simultaneous operations may be achieved typically in the following combinations:
simultaneous rig intervention on a template/manifold-cluster well and hydrocarbon production from neighbouring wells;
— simultaneous production through flowline transport systems during rig activity in the affected area.
5.3.3 Environment
System design shall comply with applicable regulations and, in order to protect the marine environment, due consideration should be taken of the following:
seabed congestion from subsea structures and pipelines;
restrictions on fishing activities and marine traffic;
discharge of hydraulic fluid;
— discharge of produced water;
disposal of purge/pigging/test fluids;
— disposal of drilling fluids and cuttings.
5.4 Design loads
5.4.1 General
All applicable loads that can affect the subsea production system during all relevant phases, such as fabrication, storing, testing, transportation, installation, drilling/completion, operation and removal, should be defined and form the basis for the design.
Accidental loads are project-specific, and should be verified by a special risk analysis for the actual application. Accidental loads can include dropped objects, snag loads (fishing gear, anchors), abnormal environmental loads (earthquake), etc.
The datasheets in Annex F may be used to record applicable loads.
5.4.2 Unpressurized primary structural components and lifting devices
Specific design requirements for unpressurized primary structural components, such as guidebases, and for
pad eyes and other lifting devices, such as running tools, are given in Annex K.
5.5 System design
5.5.1 System engineering
Subsea system engineering is an interdisciplinary approach which covers the complete system, from the reservoir to the processing facilities on the host (inclusive), with consideration of the requirements of all phases of the development, including engineering, procurement, construction, testing, installation, commissioning, operation, workover/maintenance and abandonment.
The system engineering process consists of a management part and a technical part. An evaluation of the need for application of the various system engineering processes should be performed for each specific field development, based upon the characteristics of the development.
System engineering methodology is further described in Annex H.
5.5.2 Overall design
5.5.2.1 The subsea production system should be designed to optimize life-cycle benefit while meeting functional and safety requirements.
5.5.2.2 The system shall be designed such that any operation can be suspended, leaving the well(s) in a safe state if predefined operational limits are about to be exceeded.
5.5.2.3 The system should be designed for easy fault diagnosis without system retrieval.
5.5.2.4 A high system availability should be obtained through use of simple designs and reliable products (supplier’s standard equipment preferably with a satisfactory field performance record). The system availability requirement should be established in the design basis information for the development.
5.5.2.5 Operational reliability should be documented for the subsea systems. For noncritical and temporary equipment, relaxed requirements may be accepted.
5.5.2.6 Connectors should have an inherent feature preventing unintentional release.
5.5.2.7 Means of obtaining/maintaining cleanliness in hydraulic systems to the standard required for fabrication, testing, installation, commissioning and operational periods should be included in the design.
5.5.2.8 Drag/wave-induced forces during launching/retrieval through the splash zone should be considered for design and arrangement of structural elements, including those which are not rigid members of the overall structure, e.g. hatches.
5.5.2.9 Heavy modules designed for guidelineless marine operation, such as subsea trees and BOPs, should be capable of sustaining all relevant loads and be equipped for guidance during landing of tools and modules. The load-absorbing structure should have sufficient strength to withstand loads determined by the operational parameters of the defined intervention strategy.
5.5.2.10 The subsea system should allow flushing of hydraulic circuits subsequent to connection of interfaces.
5.5.2.11 In order to improve overall availability, the possibility to replace components while other parts of the system are in operation should be evaluated during the subsea system design phase.
5.5.2.12 The subsea system should include, where justified or where required by local regulations, protection of sensitive equipment from potential damage caused by fishing gear and dropped objects. The protection should be evaluated on a probability/consequence basis. For protection related to intervention, overall design requirements should be evaluated based on operating philosophy and procedures.
5.5.2.13 Subsea production equipment installed inside the applicable safety/restricted zone of a production unit should be protected against dropped objects. Such protection should be evaluated on the basis of probability of drop/hit during operations.
