AGRICULTURE
Precision at Sea
Without proper positioning, there’s a lot that can go wrong during marine-based oil and gas operations, whether you’re positioning offshore drilling units over a wellhead, laying cable and pipes or surveying the seabed. Accurately positioning vessels on the surface is vital, and being off even slightly can lead to problems and down time that can cost companies millions.
This is a challenge that UTEC Survey, an Acteon company, knows all too well. UTEC specializes in offshore construction for the oil and gas industry, providing services such as pipe-lay installation, inspection, subsea structure installation and monitoring, precision acoustic metrology, 3D seismic node deployment, subsea mapping and Remotely Operated Vehicle (ROV) support. Vessel positioning must be precise, and UTEC trusts Hexagon | Veripos to provide the products that deliver the accuracy, reliability and redundancy their customers depend on.
“Without services like Veripos we could do nothing offshore,” said Dave Ross, UTEC’s Americas Business Unit Director. “The advances in GNSS means we can position things with 5 cm accuracy at sea. The reliability is incredible. It all starts with the position of the vessel on the surface. Subsea position will be in error if there’s not an accurate position on the surface. That means you could drill wells in the wrong place or put subsea equipment in the wrong spot. That’s all very expensive, particularly in deep water.”
Veripos provides high-performance positioning receivers that are built using NovAtel technology and provides redundant correction services that companies like UTEC and their clients need. VERIPOS leverages Global Navigation Satellite System (GNSS) and its own proprietary corrections network, which includes more than 80 GNSS reference stations, providing that all-important reliability in their solutions.
“The alternatives are lower frequency based systems,” Ross said. “Before the technology Veripos provides was available, offshore positioning was relatively inaccurate. Veripos enables precise navigation. There’s not a single construction vessel that can go to sea without a system like the one Veripos provides.”
Ross and the team at UTEC have used VERIPOS products since they opened the U.S. office in Houston back in 2006. Ross had worked with the VERIPOS management team during the company’s early days and already had a lot of confidence in their products and services. He also liked the fact that VERIPOS is an independent provider that isn’t associated with any of UTEC’s competitors.
UTEC has used VERIPOS receivers exclusively for the past four or five years in all their projects, Ross said, which have spanned 35 countries and territories worldwide.
“I’m not aware of any instances of VERIPOS systems not working,” Ross said. “The up time is fantastic, their equipment is high quality and their support is extensive and readily available. They bend over backwards to please us. When we need equipment for testing, they accommodate us. It’s like a partnership in a way. There really is a lot of trust in both directions. I find they’re a really good company to work with. Of all the things that make me lose sleep at night, VERIPOS is not one of them.”
How UTEC Uses VERIPOS
UTEC offers services that cover the complete lifecycle of offshore oil and gas development, from pre-drilling surveys to decommissioning site clearance surveys. This means UTEC has a variety of uses for precise GPS. UTEC typically turns to VERIPOS LD2, LD5 and LD7 receivers to provide that precision, Ross said. The signal type they use varies by project, but they tend to rely on Single Beam or Dual Beam options. They also use VERIPOS’ Verify QC software for some projects.
“VERIPOS offers a good range of services that can cover pretty much all of our offshore positioning needs,” Ross said. “We use VERIPOS for satellite positioning of vessels at sea, mainly associated with offshore construction. They have the hardware that gives us heading derived from GPS. They have a solution for pretty much everything we want to do with GPS.”
UTEC is one of the company's biggest clients, said Rami Tadros of VERIPOS, and is one they really take pride in serving. They have worldwide operations that are supported by the regional VERIPOS offices. The scope of their projects is very broad and is well covered by the various products and services that VERIPOS offers.
A Range of Projects
There’s no doubt UTEC has global reach, with the company successfully completing projects all over the world. UTEC has done extensive work in the Middle East, including 30,000 line kilometres of IHO specification seafloor mapping for Dubai Municipality, multi-year construction support onboard Technip’s DP lay vessel G1201 off Abu Dhabi, high-specification trenching support surveys in Qatar and pre-lay geophysical surveys in Saudi Arabia. They’ve offered pipe lay support in the U.S. Gulf of Mexico, heavy lift installations in the North Sea, and completed spool piece metrologies in West Africa—all with the help of VERIPOS receivers.Rig moving and positioning is among the various marine oil and gas projects UTEC takes on. In 2015, for example, UTEC NCS
Survey, part of UTEC, was awarded a threeyear rig move and positioning framework contract from Total E&P UK Limited. Through the contract, UTEC provides positioning services on their fleet of rigs and support vessels in the UKCS region. For rig moves, no matter the client, UTEC often must determine, via sea vessels, where a pipe is on the seabed so they know where the rig must be placed. Often, they need to survey the area for accurate placement before they can positon a rig for the first time over a well.
Logistical preparation is essential for any rig move initiative, and UTEC relies on its real-time navigation systems to execute those moves. The survey team generates coordinates and positioning updates using GPS and rig headings with gyro equipment. These technologies interface with UTEC’s navigation software for real-time viewing. The telemetry systems allow for instantaneous communication and tracking of support vessels as well as precise anchor positioning on the seabed. VERIPOS receivers and correction services play a key part in ensuring these moves are successful.
When providing solutions for survey companies like UTEC, the position has to be precise, reliable and repeatable. To fulfill that need, VERIPOS offers positioning services with centimetre, decimetre or metre level accuracy. Project requirements vary, depending on the client, the environment and the risk. UTEC team members often have to work in harsh marine conditions as they help clients properly plan, install and maintain subsea assets.
VERIPOS has developed a redundant system to ensure reliability through its Apex, Ultra and Standard services. Apex is only offered from VERIPOS and comes in three levels: Apex, Apex2 and Apex5. VERIPOS operates its own Orbit and Clock Determination System (OCDS) that derives real-time corrections for all available satellite constellations using proprietary algorithms. The OCDS uses data from the VERIPOS reference station network, which is independent from the reference stations used by JPL for Ultra services. When Apex and Ultra are used together, they provide correction services from independent networks that mitigate failures.
“Running expensive vessels precisely at sea is our main challenge, and we use VERIPOS for that,” Ross said. “In the good ole days, it cost half a million dollars a day if there was any down time or inaccuracy in position. VERIPOS helps save money through the reliability of what it does. The service that’s available and the availability of technical assistance when required means the up time is high and therefore the downtime is low, and the impact to the client is minimized.”
A True Partner
The solutions VERIPOS provides are vital to companies like UTEC and their clients. UTEC relies on accurate positioning for just about every service they provide to the offshore oil and gas industry, and any down time caused by an interruption costs their clients big, as do positioning errors. Accurate, redundant position is a must, and that’s what they get with VERIPOS solutions.
“The partnership type relationship we have with these guys is a big attraction,” Ross said. “Some other providers are controlled by competitors, so the fact VERIPOS is independent is an attractive quality. So is the reliability. They work with us on ways to save costs and the flexibility they offer helps us help our customers.”