Fugro Chance Inc. recently provided surveying services in the Gulf of Mexico for the installation and tie-in of a wye sled subsea structure. The scope of the services included surface navigation, ultra-short baseline (USBL) and long baseline (LBL) positioning, dimensional control survey, acoustic spool piece metrology and real-time 3D visualization navigation for subsea installations.
The project was separated into three phases: In Phase I, pipeline dredging and concrete coating removal was completed. These activities (along with the shallow depth) disturbed the sediments from the ocean floor to the point of causing low visibility for the pile and sled installation of the second phase. Due to the low visibility environment and the need to precisely set the wye sled, real-time 3D visualization techniques (Coda© Echoscope Dual Frequency 3D Sonar) was employed for the assistance of sled installation on the sea-floor.
Coda© Echoscope Dual Frequency 3D Sonar is a unique sonar device using phased array technology. The Echoscope generates over 16,000 beams simultaneously, producing instantaneous three-dimensional sonar images of both moving and stationary objects and enabling extremely rapid reconnaissance and inspection.
The utilization of the Echoscope®enhanced the safety and efficiency of the project. Fugro Chance’s Echoscope® services were able to give the operator an immediate 3D view of the subsea scene in order to mitigate the risk of installation inaccuracy.
Fugro Chance Inc., a member of the Fugro group of companies, provides comprehensive offshore survey solutions specialising in deepwater acoustic positioning, subsea imagery and a wide range of vessel navigation services to the oil and gas industry.
Subsea World News Staff , July 19, 2012; Image: Fugro