This paper presents an integrated seismic, petrophysical and core facies study of the Mey Sandstone Member of the Central North Sea Lista Formation. Seismic mapping and attribute analysis reveal that the Mey Sandstone Member is composed of distinct axial and lateral routing systems. In turn, the axial system can be divided into coeval western and eastern fairways defined by the underlying graben topography in a similar manner to the overlying Sele Formation (Forties) sandstones. These trends are confirmed by petrophysical analysis, which also reveals that the lateral systems are not as important as previously proposed and that the cycles of the Mey Sandstone Member prograded over time before a late stage of backstepping. These variations can be related directly to published sea-level curves. Core analysis reveals that mean grain size is the main control on sandstone quality and that similar proximal (channelized) to distal (sheet-like) changes in sedimentological facies occur to those described in the Sele Formation. It is argued that these deposits cannot be described as simple basin floor fans due to the impact of topography on turbidite flow routing and the existence of multiple entry points of sediment into the basin.

This study presents an integrated seismic, well and core-based analysis of the Maureen Formation in the Central Graben of the North Sea. Facies analysis reveals that it is possible to divide the Maureen sandstones into amalgamated, sand-and mud-prone divisions, but that the related chalk facies are complex and imply a range of depositional processes including pelagic fallout, debris flows and turbidity currents. These chalk deposits have an impact on the interpretation of amplitude-based seismic attribute volumes. Detailed petrophysical mapping, supported by seismic analysis, reveals that the Maureen sandstones were deposited in distinct western and eastern fairways controlled by the relict Mesozoic rift topography (although offset stacking is an important intragraben process). The spatial extent of the Maureen sandstones is similar to the overlying Sele and Lista formations and suggests that the broad controls on sediment routing were the same throughout the Lower Palaeogene. Other similarities between these systems include the role of sandstone texture in controlling reservoir quality (although the heterolithic nature of the Maureen sandstones means that porosities and permeabilities are lower). A pattern of intraformational progradation and late-stage backstepping of the sandstone units is likely related to sealevel variability.

A true boiling point gas liquid Chromatograph (GLC) has been designed to measure simply and conveniently GLC data for all types of petroleum streams, including crude oils and residual fuels which contain considerable portions of high-boiling materials. The instrument generates simultaneous carbon and sulfur boiling point profiles up to 538°C (C42). A quantitative measure of the nonvolatile organic portion of the sample is achieved by backflushing and combusting the material remaining in the inlet. Thus, identification of oil pollution samples is facilitated by obtaining data on the carbon and sulfur distribution and the amount of residue in a single, rapid analysis. Under certain circumstances, the total recovery capability also permits the extent of weathering of oil pollution samples to be determined directly from the chromatographic results.

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