The potential for increased oil recovery by low salinity water in jectionin the Norne field

Abstract

A study has been conducted to estimate the potential for increased oil recovery from the Norne field by injection of low salinity water. Based on reports in literature, it is assumed that low salinity water increases the water wettability of the formation rocks, resulting in more favorable oil relative permeability curves. The history matched Norne field simulation model, in conjunction with the Eclipse software, is used for the calculations. The potential for increased oil production is estimated in two main ways:

(1) Evaluation of oil volumes left inthe reservoir if low salinity water injection is not applied, and

(2) Simulations performedusing low salinity water injection function in Eclipse.

The following sensitivities for the simulations are considered:

(1) The number of injectionwells used for injection of low salinity water,

(2) the injection periods,

(3) the saltconcentration of injected water, and

(4) the threshold salinity at which low salinity waterbecomes effective.

The results from this study indicate that by injection of low salinity water into the Norne reservoir, the ultimate oil recovery may be increased by 0.5-1 %.