As the numbers of non-explored areas are decreasing, understanding the processes affecting hydrocarbon migration is of increasing importance for successful exploration and production. The effect of glaciations and ice ages has recently gained great interest from the petroleum industry due to its effect on the migration and remigration.
In northern Europe, there has been at least 30 glacial/interglacial periods over the last 3.5 million years. The impact on the migration of oil and gas is therefore very recent.
Redistribution of sediments (by glacial erosion and deposition) and repeated ice covers have affected the crust by periods of loading and unloading, which causes isostatic adjustments of the affected areas. The result is that some areas are subsiding, while others are uplifted. This resulting bending of the crust will lead to tilting of possible reservoirs. In the North Sea, large discoveries are claimed to be related to remigration of oil during the glaciations.
The glacial isostasy modelling is done by using our in-house and non-commercial software Glacimod.
Glacimod is based on 30 years of experience and research on the ice ages in the Fennoscandia (Finland, Norway, Sweden, Denmark) area, and partly Great Britain, Russia and Greenland. Incorporated in the modeling are (among other) the latest models on ice thickness and extent, glacial erosion and sediment deposition (mass balance). Glacimod is a high resolution and state-of-the-art software.
The Glacimod results are calibrated to observations of tilted shorelines, observed present rate of uplift, and the former dry land area of Doggerland (now drowned in the North Sea).