One of Houston based Mirage Subsea's Diamond Wire Saws (MDWS) was the product chosen to enable a major Saudi Arabian operator to successfully decommission a subsea pipeline.
The client needed to remove a 512 metre length of pipeline from the sea bed at a depth of 50 metres. What made the task particularly challenging was that the specification of the pipe material was ‘Super Duplex’, with a one inch wall thickness and a diameter of 12 inches. Mirage Subsea’s Diamond Wire Saw was selected to carry out the operation due to its lightweight, robust aluminium construction and impressive cutting record.
The MDWS620, with a feed stroke of 26” and the capability of cutting pipe diameters of up to 20”, was the perfect product for the task. After being lowered to the sea bed, using a three circuit hydraulic controller the saw was clamped to the pipe at each cutting location. With the diamond wire traveling at 1200 metres per minute at a feed rate set at 8mm per minute, each cut was completed in approximately 40 minutes.
A total of 22 cuts were made, with each diamond wire carrying out an average of four cuts before needing replacement.
The image above shows the first two cut sections raised from the sea bed.
- All 22 cuts were made along the pipeline within 72 hours, enabling the sections to be brought on deck in manageable sizes of around 23 metres in length.
- Upon project completion, with the disused pipe out of the way the customer was able to construct a new pipeline.
- The saw performed to the customer’s satisfaction and the project was also supported by an experienced Mirage engineer, who supervised the cutting operations and provided hands-on support during the project.
Innovative Product Development
The MDWS range was introduced to the market in 2014 following an extensive product development project carried out by Mirage’s in house mechanical design team and Houston based Mirage Subsea’s ROV tooling and mechanical design and development team.
The outcome was a range of four machines, each capable of delivering high performance solutions for cutting pipelines, multi-string casings, piles, platform legs, wellheads or topsides equipment. Products in the DWS range are ideal for quickly cutting through a range materials and resisting compressive forces.
Related accessories available to carry out operations such as this include;
- Power Packs
- Topside Hoses
- Spooled Umbilicals
- Deployment Baskets
Get in touch to find out more about our range of Diamond Wire Saws.