OHM Express Sets Sail in North Sea
The OHM Express, Offshore Hydrocarbon Mapping plc's new flagship for its CSEM operations, is currently sailing to its first location, offshore Norway, to begin work for a number of major oil companies. The OHM Express has been extensively upgraded and modified in yards in Poland and Sweden to adapt it specifically for deployment on Controlled Source Electromagnetic Imaging (CSEM) data acquisition surveys.
The 3,200 dwt vessel is 110 meters long and has hold capacity to store large amounts of equipment as well as provide comfortable indoor workshop facilities. The large size and stability of the vessel together with its carefully designed handling systems will significantly widen the Company's safe operating envelope with respect to sea conditions, allowing the vessel to work safely for longer periods of time.
The vessel's propulsion systems have also been upgraded to provide the dynamic positioning and low speed maneuverability necessary for survey operations whilst also allowing for high speed and economical transits between survey areas.
OHM Express has been chartered for five years and is the result of a year of planning and design by OHM's technical staff together with valuable input from the vessel's owners Seatrans of Norway. The modifications and improvements include:
--Tailored handling systems for safe and rapid deployment and recovery of CSEM sources and receiver. --Rapid loading systems to minimize time spent loading stores and consumables during port calls. --A new azimuthing thrusters system to give full maneuverability for receiver recovery and deployment. --New modern accommodation facilities complete with wi-fi, exercise, and conference suites for crew and clients. --Broadband satellite communication providing 24 hour access to the Company's shore based data processing facilities and to the Aberdeen based operations management team.
Dave Pratt, OHM's Chief Executive Officer, said:
"Our priority has always been to conduct surveys in a safe and efficient manner. The five year charter of the OHM Express has allowed us to make modifications that not only gives us considerable operational flexibility but also increases the comfort of working conditions for our operational staff."
Controlled Source Electro-Magnetic imaging (CSEM) is potentially the most important new technology in the field of offshore oil & gas exploration since the advent of 3D seismic some twenty years ago. CSEM is an innovative offshore geophysical technique, employing electromagnetic remote-sensing technology to detect the presence and extent of hydrocarbon accumulations below the seabed.
The CSEM survey uses a dipole source that is towed just above the seafloor to transmit an electromagnetic field into the earth. This field is modified by the presence of subsurface resistive layers and these changes are detected and logged by an array of receivers placed on the seabed. Because hydrocarbon-bearing formations are highly resistive compared with surrounding formations, a CSEM survey can indicate the presence of oil and gas in offshore situations. CSEM imaging can significantly reduce the risk of drilling dry exploration wells creating considerable value for oil & gas explorers.
The technique was first used offshore Angola in 2000 and has since become a key deepwater exploration tool for the major oil companies. Very high success rates have been quoted by these companies, particularly when the results of a CSEM survey have been integrated with seismic interpretation.
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