1,721,040 research outputs found
Diagenesis of the Khuff Formation (Permian–Triassic), northern United Arab Emirates
No full textThis diagenetic study (including fieldwork, petrographic, fluid inclusion, and stable isotope investigations) deals with the outcrop of Upper Permian–Lower Triassic carbonate rocks, which are equivalent to the Khuff Formation. The studied succession, which outcrops in the Ras Al Khaimah region, northern United Arab Emirates, comprises three formations, including the Bih, the Hagil, and the Ghail formations. The study focuses on unraveling the conditions and fluid compositions encountered during diagenesis of the succession. Emphasize is also made on linking diagenesis to major stratigraphic surfaces and to highlight reservoir property evolution and heterogeneity of the studied rocks. The evolution of fluids and related diagenetic products can be summarized as follows: (1) formation of near-surface to shallow burial, fine-crystalline dolomite (dolomite matrix) through pervasive dolomitization of carbonate sediments by modified marine pore waters; (2) formation of coarse-crystalline dolomite cement by highly evolved marine pore waters (13–23 wt.% NaCl eq.) at elevated temperatures (120–208°C), and (3) calcite cementation by highly saline fluid (20–23 wt.% NaCl eq.) at high temperature (170–212°C). A final calcite cement generation has been formed by the percolation of meteoric fluids during uplift. Fracture- and vug-filling diagenetic minerals are mainly restricted to the mid-Bih breccia marker level, suggesting preferential focused fluid flow through specific stratigraphic surfaces as well as along tectonic-related structures. Reservoir properties have been evolved as result of the interplay of the original sedimentary texture and the diagenetic evolution. Porosity is higher in the Bih Formation, which is dominated by dolomitized packstones and grainstones, than in the Hagil and Ghail formations, consisting mainly of dolomitized mudstones and wackestones. Image analyses were used to quantify the visual porosity in thin sections. The highest porosity values were measured in the Bih Formation, which is characterized by significant amounts of vug- and fracture-filling cements. This feature is attributed to the increase of porosity owing to substantial dissolution of abundant intergranular and vug-filling cements. In contrast, the Hagil and Ghail formations, which consist of finer-grained rock than the Bih Formation, were less cemented, and thus, the porosity enhancement by cement dissolution was insignificant
Hydrothermal dolomitization in the Upper Triassic Ghalilah Formation, North-eastern United Arab Emirates
No full textDiagenesis of the Permo-Triassic rock sequence of northern U.A.E.: Lessons learnt from Khuff Formation analogues
No full textFracture mineralization and fluid flow evolution: an example from the Permian-Triassic carbonate successions of United Arab Emirates
No full textFractures are often the primary conduits for pore fluids, and thus have an important impact on the diagenetic and reservoir quality evolution of the host rocks. Therefore, fluid flow can be used to
develop conceptual models for the spatial and temporal distribution and connectivity of reservoir porosity and permeability on a regional and basinal scale. In the context of the hydrocarbon-rich Middle East, the Permian-Triassic Khuff Formation hosts huge gas accumulations in the subsurface of the Arabian Plate. Reservoir properties of this formation are strongly influenced by depositional facies and diagenetic evolution (Ehrenberg et al., 2007; Fontana et al., 2010; Moradpour et al., 2008). In the Emirate of Ras Al Khaimah (RAK), in the northeast of the United Arab Emirates (UAE), there are excellent outcrops of the Permian-Triassic rock sequence, which is partly correlatable with the Khuff Formation (Strohmenger et al., 2002; Maurer et al., 2008, 2009). In this study, which involves fieldwork,
petrographic, fluid inclusion and isotope (0, C and Sr) investigations, outcrops of Permian-Triassic carbonate rocks have been studied to relate fracture mineralization to tectonic history of the area
Diagenesis and Fluid System Evolution of the Khuff Formation Outcrop Analogues, Northern United Arab Emirates
No full text3D stratigraphic forward modelling of the Upper Jurassic Arab Formation: an onshore Abu Dhabi (UAE) case of study.
No full textDiagenesis and Reservoir Quality Evolution of the Permian Bih Formation (Khuff Reservoir Analogue), Ras Al Khaimah, United Arab Emirates.
No full textDiagenesis of the Permo-triassic Succession of the Northeastern UAE, an Outcrop Analogue of the Khuff Formation
No full textField-scale forward modelling of a shallow marine carbonate ramp: the Upper Jurassic Arab Formation (onshore Abu Dhabi - UAE)
No full text
- …
