The Leman Field is the largest discovered gas field in the southern North Sea. Production is from Rotliegend Sandstones which predominantly have an aeolian origin. In the Shell/Esso acreage the flanks of the Leman Reservoir are sparsely drilled, and potentially large amounts of gas remain in place. In these areas only the relatively poor quality uppermost part of the Rotliegend Reservoir is above the gas/water-contact. Analysing reservoir properties in the uppermost Rotliegend indicates that the variation in reservoir properties within a lithofacies is significantly larger than the variation in average reservoir properties between lithofacies. Sedimentary structures are the most likely cause for this internal heterogeneity. Consequently, drilling a well parallel to the main foreset dip, the direction of maximum heterogeneity, should maximise productivity. In the Leman Field this means that wells should be drilled parallel to the main paleowind direction, which is from southeast to northwest.

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