Cairn Energy PLC, the Edinburgh-based oil and gas exploration and production company, has successfully deployed Centek’s Itsfu Auto Fill Sub in drilling operations in its 2011 Greenland Drilling campaign. The Itsfu provides controlled drill string filling in one third of the time of alternative methods and prevents uncontrolled, hazardous spillage of well drilling fluids onto the rig floor.
“After learning how the Itsfu works, we are now able to fill 10 stands of 5 7/8″ TT585 connection string in around three minutes,” said John Boyle, Drilling Manager, with Cairn Energy. “This saves both time and ensures the immediate area of the rotary table remains clean compared with conventional filling practices.”
Around every 1,000 feet of running in, the drill string must be filled with fluid to equalize the pressure inside and outside the pipe to avoid it collapsing and to balance the well. The filling process interrupts running in, so speed is very important.
Every 10 stands the Itsfu is made up to the drillpipe by means of the integral swivel and the charge pump is started. The gooseneck outlet is automatically closed by a plastic disc to prevent air entering, and the closed-system drillpipe can now be filled in around one third the time of conventional methods. Once the drill pipe is full, the plastic disc comes free, discharging fluid from the gooseneck as a tell-tale. The mud pump is switched off, and with no pressure or air present, the Itsful fill-up tool can be readily removed by hand from the drillstring, without fluid spurting, and hoisted back to its storage area.
“The Itsfu offers real savings of time as it minimises spillages and cleaning up,” said Cliff Berry, Sales and Marketing Manager at Centek Limited. “Also because it screws into the drill pipe at the rotary table rather than by disconnecting the top-drive, the next pipe stand can be made ready while drill string filling is in progress.”
The Itsfu is drill-team friendly and as simple to install as a circulating sub. In addition, as the top drive is not involved in filling, there is no danger of damaging the top drive saver sub threads and the top drive is also available if needed in the open hole.
The Itsfu is available to drilling teams now and can be rented on a daily basis.
- Cairn draws a blank at second Arctic well (guardian.co.uk)
- Cairn Energy setback in Greenland (bbc.co.uk)
- Cairn Energy stays optimistic with Arctic drilling (cbc.ca)