OSJ article – New drilling initiative completes subsea wellhead foundation
13 August 2018
A new joint project has recently completed a ground-breaking subsea wellhead foundation contract in the Carnarvon Basin, writes Mark Pointon
A new Australian/Norwegian partnership - involving Woodside Energy, ICON Engineering, Neodrill AS and Siem Offshore Australia - has successfully installed and recovered a Conductor Anchor Node, the CAN-ductor, at Woodside Energy’s Ferrand-1 exploration well, which is located in Block WA-404-P, approximately 260 km north-west of Dampier, Western Australia.
Perth-based ICON Engineering Pty Ltd teamed up with Neodrill AS to fabricate and install the device using the Siem Offshore vessel Siem Amethyst. A spokesman said it was a logical tie up for Neodrill to partner with ICON, which has a 21-year history of offshore installations and engineering solutions.
In doing so, the project set a number of firsts for the CAN-ductor Anchor Node, an innovative cost-saving drilling initiative for exploration wells and production wells.
The Ferrand-1 well, at 1500 m, is the deepest that the CAN-ductor has been used to date; it is the first in the Southern hemisphere and the first to be deployed and recovered from an anchor-handling vessel (AHTS).
Woodside’s ‘Punch and Go’ concept
At the OTCAsia conference in 2016, Woodside Energy chief science and technology manager Neil Kavanagh spoke of a new technology Woodside was developing that would help lower costs, called the “Punch and Go” concept. It was devised from a study the company undertook to examine the drilling of subsea exploration wells from a light intervention vessel.
“All we want to know is, is there a reservoir, how thick is it, and are there hydrocarbons inside?” said Mr Kavanagh. He continued, “Taking some of the work that has been going on around the world, we asked the question, could a lightweight intervention vessel using a pre-installed conductor and surface casing drill into a reservoir and drill a very slim hole? What we learned is the answer to that question is yes.”
“We asked, could a lightweight intervention vessel using a pre-installed conductor and surface casing drill into a reservoir and drill a very slim hole? We learned is the answer to that question is yes”
Neodrill/ICON Conductor Anchor Node
The first project to use the “Punch and Go” concept was completed in late July 2018, using the Norwegian Neodrill AS patented suction-based Conductor Anchor Node. The technology was developed to provide the option of pre-installing drilling conductors from anchor-handling or light construction vessels, instead of the costlier drilling rigs, thereby significantly reducing drilling costs.
This type of anchor node is in principle a combination of a specially designed suction anchor and a centrally placed single length of conductor. The advantages of the system are that it reduces operational and technical risk by providing a strong well foundation with verified load capacity.
ICON managing director David Field said pre-installing a Neodrill CAN-ductor with a light vessel (like the Siem Amethyst), instead of a drilling rig cut days from the rig time required to safely drill offshore wells. “This is in addition to the higher operational and accidental well load capacities, fatigue risk mitigation and reduced environmental footprint [that the unit provides]”, he said.
At the time the project was awarded in 2017, Neodrill chief executive officer Jostein Aleksandersen said “The CAN-ductor has proven to save three to four rig days, including plugging and abandonment (P&A) operations.”
He further explained that “its ability to be deployed by a less expensive vessel, such as an AHTS or construction support vessel means the operator’s drilling budget can be reduced, whether they are exploration or production wells.
Manufactured in Batam Indonesia, the 16 m CAN was loaded onto the Siem Amethyst for installation in February 2018.
Siem Amethyst is a 91 m dynamically positioned (DP) AHTS that has powerful 28,000 bhp engines and a bollard pull of 297 tonnes.
During installation, the Amethyst’s fully redundant DP system was used to accurately keep the vessel in the required position and provide a platform for the remotely operated vehicle used in the deployment process.
The suction anchor is deployed once lowered to the seabed using the vessel’s anchor-handling winches. When in position, with its 16 m body embedded on the sea floor, the centre conduit is used to accommodate the conductor and provide its necessary top support.
This operation was carried out ahead of the drilling Rig MS-1’s arrival and removed the 36” and 42” hole drilling, conductor running, and cementing operations from its drilling schedule.
Speaking after the unit was successfully recovered and returned to Dampier Western Australia, in July 2018, marine manager for Siem Offshore Australia Charlie Baker said: “Siem is delighted to be involved in the first CAN-ductor project in the Southern hemisphere. We quickly identified this as a real opportunity to demonstrate that our high-spec large anchor handlers, with integrated Itech7 –WROV (Work Class Remotely Operated Vehicles) are extremely versatile vessels.
“This particular project required a real collaboration from all parties, a true team effort. It was stimulating during the planning phase and exciting for it be executed with such a great success. Woodside, ICON, Neodrill and Siem have established that this form of subsea infrastructure is successful.”
To view the article in the OSJ click here
The CAN being fabricated
The CAN is deployed using the vessel’s anchor-handling winch