In 2011, the Russian engineering company PeterGaz LLC has been performing integrated offshore engineering survey along the route of the South Stream Gas Pipeline in the deep-sea areas of the Black Sea. The survey operations include exploration of the bottom sections and of the subsea strata using the HUGIN 1000 for 3000 Autonomous Underwater Vehicle. Operations are performed from on-board the GSP Prince research ship. By now, about a half of the 900-kilometer long route has been explored, with most of the route lying at depths of over 2 kilometers.
The survey has been performed using a fast and economical method of recording underwater sound velocity with the aid of the compact high-speed UnderwaySV winch developed by Oceanscience (USA) and the RapidSV underwater sound velocity recording profiler made by Valeport of the UK.
An innovation, to the bottom profiling method employed, has been the use, in combination with the RapidSV sound velocity rate sensor, of the cantilever-type spool that makes it possible for the probe to plummet practically in the free-descent mode as the cable unwinds. The sensor descends in the water at the speed of up to 5 m/sec and reaches the depth of 1,000 meters in a mere three to four minutes time. At the same time, the winch has a high wind-up speed, which makes it possible to raise the sensor quickly. As a result, a record-breaking reduction in time has been achieved in bottom profiling while maintaining a persistent high quality of the data collected.
It only took PeterGaz personnel 35 minutes to record an underwater sound velocity profile of a 1,730-meter deep section of the Black Sea. This result surpasses the previous record high for sound velocity profiling of the water column, which measured 1,563 meters and was set by the National Data Buoy Center with the U.S. National Oceanic and Atmospheric Administration. The GSP Prince research ship’s personnel were delighted with the speed of data collection and with the high quality of the data obtained.
PeterGaz LLC is an engineering company whose main fields of activity include engineering design of hydrocarbons production/transportation facilities, performance of offshore and onshore surveys, engineering design approvals with the respective RF government authorities, processing of appropriate authorizations for construction projects, and construction management as project manager/developer or EPC contractor.
External link: http://www.oilandgaseurasia.com/articles/p/152/article/1704#