Operator seeks better method of sand control

A major operator offshore Nigeria planned to complete 16 openhole wells in an unconsolidated low-pressure sandstone formation. The formation contained compartmentalized heavy and viscous oil with variable fluid contact. Extended-reach wells were being used to access and drain the reserves. Lateral variations in permeability tended to create unbalanced inflow along the lateral, resulting in premature breakthrough of unwanted fluids. The operator needed to eliminate the problems that had interfered with production in wells completed in a previous drilling campaign in the same field. Those wells had used only stand-alone wire-wrapped sand screens, which had been unable to regulate flow, resulting in total water production.

ResFlow ICDs succeeded where stand-alone screens could not

To mitigate these problems, the operator chose the ResFlow inflow control device (ICD). ICDs are self-regulating nozzles that help balance flow across the reservoir. The nozzle configuration, including size and quantity, is designed prejob and can be adjusted at the rig site before a completion is run.

ICDs regulated flow and prevented wells from watering out

The initial well was completed with 93 ICDs distributed evenly along the horizontal section. When the well began producing, production logging test results showed that inflow was distributed uniformly from heel to toe, a length of almost 4,000 ft [1,219 m], and water breakthrough was greatly reduced compared with wells from the previous campaign.

This meant that the ICDs were performing as designed—improving sweep along the lateral, deferring the onset of water and gas breakthrough, and preventing the well from watering out at any single point. The oil was able to flow freely over the entire length of the lateral. As a result of this success, the operator elected to install ResFlow ICDs in the remaining 15 wells.