Logan Industries, a hydraulic repair, manufacturing and rental company, has successfully completed a reduced bore direct acting tensioner (RB-DAT) project to enable the use of the DAT in shallow water.
The project required making an existing deepwater DAT suitable for shallow waters using the existing rod and barrel, external footprint and interface points, while maintaining the same pressure rating and tuning the operating characteristics from deepwater to shallow water.
Logan used a sub-arc welding machine and precision barrel positioners to manufacture the equivalent of reduced bore direct acting tensioner barrels and inserted these barrels (which become reduced bore sleeves at this point) into the existing DAT to effectively reduce tensioning forces between the marine riser and subsea wellhead. This improved the operational performance of the DAT in shallow waters with lighter loads.
Dean Carey, technical director, Logan, says, “We provided the operator with a DAT that looks the same, but provides better operational performance in shallow water. We were able to save the client full replacement costs, while accommodating their existing interface points and control lines. We provided an option to the operator that wasn’t readily available and gave them a drop-in solution. Also, it gives them the ability to convert and un-convert when their water depths change for different well locations. We see this as a huge cost saving for DAT owners, giving the drilling contractors more flexibility in where they can operate – in both shallow and deep waters.”
The DAT conversions are set to ship to the customer in April 2019.