The AGE Riserless Pump System has been widely adopted throughout Australia as an alternative to the traditional riser column method of water transfer to surface for electric submersible pumps. The system works by sealing and supporting the pump in the casing with an inflatable packer. Utilising the bore casing itself as the riser, the frictional head losses incurred during transfer are greatly minimised due to the decreased velocity. Over time, this increase in operational efficiency leads to substantial power savings – in the order of tens, to hundreds of thousands of dollars per year.
The Riserless system is ideally suited to large, deep bores and offers even more advantages in new bores where the production casing and drilled hole diameter can often be reduced without affecting bore production rates. For ease of installation, all components are lowered into the bore using small diameter dual sealed AGE hanging pipe. The packer inflation tubes, motor cables and vent lines are secured to the hanging pipe at regular intervals to ensure they do not slump and cause issues. With the assembly at the required depth, the packer is inflated to support the pump and seal the casing. When the inflation tube and motor cables have been sealed, the bore is ready for pumping.
In addition to the reduced operational costs, the system also offers a number of other benefits over traditional electric submersible pump completion:
• As the water bore casing acts as the water conduit, no separate riser column is required.
• All installation/retrieval operations can be performed using a simple winch or crane arrangement, rather than mobilising a drill rig.
• For new installations, smaller diameter bore holes may be used since the hole size no longer depends on pump riser column clearances.
• The down hole equipment can be very quickly and simply moved to another depth, removed entirely for servicing or re-location.
• Since the water bore casing above the pump is sealed, it remains water-filled regardless of pump drawdown, eliminating corrosion which may result from changing water levels.
• The inflatable packer can be made to accommodate a through tube which allows static head levels to be monitored at the pump inlet, avoiding potential negative head problems due to excessive drawdown.
All water bore equipment is manufactured from stainless steel materials and potable water grade rubber compounds compliant to AS/NZS:4020.