Summary This paper presents a case-study of an investigation into a Middle Eastern carbonate reservoir, the Mishrif Formation of eastern offshore Abu Dhabi, and its lateral equivalent, the Shilaif Member of the Salabikh Formation. The work represents a major part of a sedimentological/seismic stratigraphic study, the aims of which were to model reservoir facies and geometry, and to predict areas of best reservoir potential. The study is based on interpretation of cores, cuttings and wireline logs from 30 wells distributed over some 200 km 2 . The Mishrif of the study area forms part of an extensive Cenomanian carbonate platform. It represents deposition on a local leeward (i.e. shelfward) margin which prograded westwards into an intrashelf (the Shilaif) basin. Six lithofacies associations were recognized in the Shilaif and Mishrif, representing lateral and vertical transitions from silt-grade basinal pelagic-foraminiferal wackestones (I), through a platform margin sequence (II) which coarsens upwards to coarse rudist/ostreiid shoal (III) and biostromal (IV) packstones and grainstones. Shoal and biostromal facies are overlain in the east by bedded back-shoal packstones (V) and nodular micritic platform-lagoonal (VI) sequences. A significant unconformity exists at the top of the Mishrif. Three stages of diagenesis have been recognized in Mishrif limestones: early (micritization, submarine cementation); unconformity-related (extensive leaching, freshwater cementation); and burial diagenesis (stylolitization, fracturing, burial cementation, neomorphism). Leaching and burial cementation were the most important diagenetic events and significantly overprint the generally simple variations in reservoir character due to original depositional facies distribution. Most favourable porosity and permeability values occur in coarse-grained shoal, upper-slope, and biostromal sediments (upper II, III, IV) where exposed and leached at the final platform margin, whereas to the east, in the platform interior, these facies have suffered severe burial cementation. The slight regional eastwards dip of the Mishrif reservoir, its westwards pinch-out into basinal facies, and the presence of a proved top-seal fulfil the requirements for stratigraphic trapping of hydrocarbons, with the best reservoir facies advantageously situated. A well drilled to test this play encountered the predicted sequence but found only residual oil. This may be due to imperfect lateral or bottom reservoir sealing.