Riserless Pump System
The Riserless Pump System was developed to allow the casing itself to be used as the riser for an electric submersible pump by sealing and supporting the pump in the casing with an inflatable packer.
This system eliminates the need for a separate riser column ensuring much lower frictional pumping losses and providing a broad range of contingent advantages.
The riserless system is ideally suited to large, deep bores and offers even more advantages in new wells where the original casing and drilled hole diameter can often be reduced without any reduction in bore production rates.
For ease of installation all components are lowered into the well using either a stainless steel wire rope or IPI hanging pipe. The packer inflation tubes, motor cables and vent lines are secured to the deployment pipe at regular intervals.
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 at the head works, the well is ready for pumping.
Benefits of Riserless Systems
•The riserless pump system presents an attractive alternative to traditional submersible pump completions and offers several advantages over these methods:
•Since the well casing acts as the riser, no separate riser 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 holes may be used since the hole size no longer depends on riser clearances.
•The down hole equipment can be very quickly and simply moved to another depth or be removed entirely for servicing, re-location etc.
•Since the casing above the pump is sealed, it remains water filled regardless of pump drawdown thus 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.
•The larger diameter riser leads to lower frictional head loss in pumping the well and thus lower power consumption.