The Magnus Field: extending field life through good reservoir management and enhanced oil recovery

Abstract

The Magnus Field has been on production since 1983. Production of oil is from intra-Kimmeridge Clay Formation age turbidite sandstones. The individual lobes of the turbidites are generally fining-up, or have fine tops. Waterflood production tends to sweep the lower part of the units very effectively, thus leaving an unswept oil target at the top of many flow units. An enhanced oil recovery (EOR) scheme has been implemented on the Magnus Field by bringing gas, which had no access to a market, from the Foinaven and Schiehallion fields West of Shetland. Because the gas is mainly methane it is taken via the Sullom Voe Terminal (SVT) on the Shetland Islands where it is enriched by injecting higher molecular weight gases. This enrichment improves the effectiveness of the EOR process at Magnus. The scheme adds value not only at the Magnus Field but also to the West of Shetland fields and at SVT. The gas can also be used as fuel to replace diesel at SVT, bringing environmental benefits.