ANSI API RP 17M pdf download.Petroleum and natural gas industries — Design and operation of subsea production systems
This part of ISO 1 3628 provides functional requirements and recommendations for ROT intervention systems and interfacing equipment on subsea production systems for the petroleum and natural gas industries. This part of ISO 1 3628 does not cover manned intervention and ROV-based intervention systems (e.g. for tie-in of sealines and module replacement). Vertical wellbore intervention, internal flowline inspection, tree running and tree running equipment are also excluded from this part of ISO 1 3628.
2 Terms, definitions and abbreviated terms
For the purposes of this part of ISO 1 3628, the following terms, definitions and abbreviated terms apply. 2.1 Terms and definitions 2.1.1 subsea intervention all work carried out subsea 2.1.2 primary intervention all work carried out during the scheduled intervention task 2.1.3 ROT system dedicated, unmanned, subsea tools used for remote installation or module replacement tasks that require lift capacity beyond that of free-swimming ROV systems NOTE The ROT system comprises wire-suspended tools with control system and support-handling system for performing dedicated subsea intervention tasks. They are usually deployed on liftwires or a combined liftwire/umbilical. Lateral guidance may be via guidewires, dedicated thrusters or ROV assistance. 2.1.4 deployment system all equipment involved in the launch and recovery of the ROT system 2.1.5 heave-compensated system system that limits the effect of vertical vessel motion on the deployed ROT system2.1.6 skid system storage, transportation, lifting and testing frames to facilitate movement of the ROT systems and the modules and components to be replaced or installed NOTE Skids are used in combination with a skidding system. 2.1.7 sealines all pipelines, flowlines, umbilicals and cables installed on the seabed 2.1.8 termination head part of the PICS interfacing with the end of the sealine 2.1.9 pull-in head part of the pull-in system acting as attachment point for the end of the pull-in wire
3 System selection
3.1 General The design, configuration and operation of the ROT intervention system impacts directly on the LCC for the entire SPS. In order to obtain an SPS design providing safe and cost-effective intervention operations, it is important to obtain a closed loop between SPS design and intervention system design. See Figure 1 . An ROT intervention system typically comprises the following: a) ROTs for dedicated intervention tasks, b) deck handling equipment, c) ICS, d) deployment/landing equipment, e) ROV spread interfaced with ROT systems. An illustration of the main features of an ROT intervention system and associated equipment is shown in Figure 2. The breakdown of the ROT intervention system into sub-elements and components as presented in this part of ISO 1 3628 should not pose limitations on the selection of new intervention concepts whose functionality and reliability can be documented. Configurational options for the ROT intervention system and interfacing equipment, such as intervention vessel and ROV systems when used, are shown in Figure 3.
3.2 Deck handling equipment Deck handling equipment and launching techniques shall be selected to ensure that a wide range of vessels can be used. Flexibility shall be provided without compromising safety and reliability of the work, both on surface and subsea. Main issues are: ? means of moving intervention equipment on deck (skid systems vs. use of vessel cranes); ? means of deploying and landing ROT systems (winches and simple mobile A-frames vs. use of complex, purpose-made heave-compensated systems); ? means of installing on and removing from the intervention vessel. The selection of equipment shall be dictated by the nature of the intervention task (e.g. tie-in operation, module replacement), environmental considerations affecting the operation and time available to carry out the required operation. 3.3 Intervention control system (ICS) The ICS shall be designed for control and monitoring of a) ROT function testing on deck, b) ROT status during running, if required,c) ROT functions during the intervention task.