Our experienced team of specialist have completed over 500 rig-related positioning projects from shallow to deep water rig operations, all around the world over the last 10 years. iSURVEY has developed advanced and robust survey and positioning solutions to support the complete range of offshore rig and mooring operations
Jack-up rig moves
iSURVEY has a long track record of positioning jack-up rigs alongside existing structures and in open locations. We have well proven standardised solutions based on Global Navigation Satellite System (GNSS) positioning in combination with relative positioning systems. These include robotic total stations and/or real-time kinetic which are used to navigate the rig in a safe and controlled operation. Prior to rig moves, iSURVEY can offer a full dimensional control survey, prism installation and datum point establishment on existing structures/platforms.Standardised mobilisation reports and rig move survey reports are provided, containing calibrations, verifications and as-built data to guide the client with easy access to necessary data and positions.
Semi-sub rig moves
iSURVEY has well proven, extensive experience in positioning semi-submersible rigs safely on to location. As with jack-up rigs, we offer effective solutions based on GNSS to navigate the rig in a safe and controlled operation.The increasingly common technique of pre-installing anchors using an AHV complete with ROV, prior to the actual rig move, is also supported. A standardised mobilisation report and rig move survey report are provided, containing required calibrations, verifications, as-built data and anchor catenary calculations.
FPSO and mooring operations
Where an FPSO is being moored either during initial hook-up, reinstatement or just other mooring modifications, or rigs are skidding their position on existing moorings, the following services are provided:
- Survey and positioning support during FPSO installations
- Unmanned rig position monitoring systems (iMON)
- Rig gyro calibrations
Where the subsea position, heading, inclination and/ or height of a wellhead/ guidebase is required, iSURVEY is able to provide the following services:
High accuracy positioning using Long Baseline systems (LBL) for positioning of wells/wellhead guidebase in deeper water
- LBL arrays of typically 4-5 transponders
- Topside system on rig/drilling vessel
- Position reference is obtained from range-range geometry from the transponder locations