Sonardyne Aids EMAS Chiyoda Subsea Execute Julimar Project
Sonardyne said it has supplied a specialist survey software to help complete a metrology campaign off the coast of Western Australia in just 26 hours.
The project was led by EMAS Chiyoda Subsea (ECS), who was contracted by Apache Energy to install infrastructure at the Julimar natural gas field. The scope of work included installation of two manifolds, connected by five 30 metre vertical spools and five 80 metre horizontal spools.
Surveyors estimated that to gather the 10 metrologies at Julimar could take anywhere between 60 and 80 hours. By opting to use Sonardyne’s Connect software package to streamline the process, the entire operation was subsequently completed in just 26 hours, the company explained.
The work at Julimar was conducted from ECS’ heavy lift, deep water, multi-lay vessel Lewek Constellation, operating with Sonardyne’s 6G (Sixth Generation) acoustic positioning transponder hardware. These were deployed on the seabed and placed in survey receptacles attached to the various structures.
During the operation, the survey team collected depth and profile data using an ROV held digiquartz depth sensor, then heading and inclination data at each survey receptacle whilst also collecting Long BaseLine (LBL) acoustic range measurements. The collected data was analysed as one data set. The site’s shallow water depth meant paying particular attention to sound velocity.
Once the data QC was completed, each spool metrology was processed and a final report generated which contained a summary of the results including hub-to-hub horizontal distances, slant range, depth differences, attitudes, plus details of the calculations to support the results.
Gerry Quinn, survey manager (Operations) with EMAS CHIYODA Subsea said: “Our team were blown away with the speed in which these metrologies were undertaken – in particular the unprecedented time of 26 hours total to measure five 30 metre vertical jumpers (Manifold to Wells) and five 80 metre horizontal jumpers (Manifold to Manifold to PLEMs) in 80 metres water depth. The 4-man survey team conducted not just the metrology, but the overall operations as smoothly and as efficiently as one.”