LinkQuest

Shell Successfully Deployed LinkQuest’s
9600 Baud Acoustic Modems with ADCP

Shell Oil Company has successfully completed deployment of LinkQuest's high speed underwater acoustic modems in the Gulf of Mexico in high-noise offshore drilling environment. Shell used LinkQuest’s acoustic modems instead of cable to upload current profiles from sub-sea ADCP in real-time. The reliability and efficiency of the modems were validated in the test.

From November 3, 1999 to December 19, 1999, LinkQuest's UWM2000 acoustic modem was deployed with a 300 kHz RDI Workhorse ADCP at 900 meters below sea surface from an actively drilling platform, Ocean Worker, in the Gulf of Mexico. The surface modem, connected to a PC on the platform, was hung about 30 meters below sea surface from the platform. Due to the robustness of the modem, system installation was easily accomplished with the help of an ROV.

The ADCP was configured to send current profile every 15 minutes. Overall, more than 4000 current ensembles (2.5 mbytes) of data were sent from the Workhorse ADCP. While data were sent through the acoustic link in real-time, the ADCP recorder also kept a record of all the current ensembles. By comparing the logged current ensembles at the surface PC obtained through the acoustic link and the current ensembles in the ADCP recorder, it is concluded that there was no loss of any current ensemble and no error in the data.

Over the past few years, Shell has tested acoustic modems from several manufacturers for current monitoring. This deployment is the first time Shell has succeeded in using acoustic modems reliably with ADCP for long term current monitoring. Shell is pleased with the results and placed an order soon after the completion of the deployment. Shell plans to use LinkQuest's deep water modems for further deployment with ADCP in the Year 2000.

LinkQuest has integrated its modems with RDI 300 kHz Workhorse Sentinel, 1200 kHz Workhorse Monitor and 75 kHz Workhorse Long Ranger. The integration of the modems with Workhorse ADCP is transparent and easy. The users will still be able to use RDI software such as WATCH, TRANSECT and BBTALK in the way they used to. The modems can also upload mega bytes of data from Workhorse recorder using the Y-modem protocol.