Sulphate Removal and Water Injection Brochure

Water is injected into the reservoir to enhance oil recovery (EOR) by maintaining the reservoir pressure and to sweep displaced oil towards the production wells.

Where oilfield reservoir formation water contains significant amounts of barium and/or strontium, injection of seawater can cause barium and strontium sulphate scale to be formed. These scales have the effect of reducing reservoir permeability and can also become deposited in production pipe internals.

Barium and strontium sulphate scales are notoriously difficult to remove since they cannot be easily dissolved. Squeeze inhibition treatments are often utilized to improve the well permeability but these are extremely difficult to control and cannot be applied to complex sub-sea networks or from floating production storage and off-loading vessels (FPSOs). Where pipeline scaling is experienced, this has to be removed by mechanical means.