## 4 Results
### Sequence SS1 Cycle IV  
Most of this sequence is deposited over a carbonate megabank and consists of chalkified fine-grained limestones (mudstones, wackestones, and packstones) alternating with smaller amounts of sucrosic dolomites and tighter over-dolomites. We observed a trend with decreasing gamma-ray and density can be observed from bottom to top. The succession is mainly dominated by argillaceous limestone at the bottom FS1 and tight dolomite. Towards the top of the interval, the same can be assumed for E11-3, and thus a lateral extent of these layers of at least 2.6 Km. This sequence tends to have a laterally more persistent reservoir quality, with the average gross porosities ranging between 17% in E11-2 and E11-3 and 21% in E11-1. The rest of the porosity consists of argillaceous limestones. At the top of this sequence, an FS2 interval is present with foraminiferal limestone packstones and partially argillaceous lime wackestones with cemented coral fragments. The compaction features, such as horsetails and stylolites, are common. The unit is present throughout the buildup area, with a uniform thickness in the region of 45-52 m. Although the average porosities in the wells range between 7 (E113) and 14%, the unit contains tighter streaks that render it overall a poor reservoir rock. The tighter part (FS2) of the unit is assumed to act as a permeability barrier to production due to the lower permeability values (Figure 7). Figure 6: Core and thin sections of rock types: (**A**) dense argillaceous shale (RT1), (**B**) cemented argillaceous limestone (RT2), (**C**) moultic limestone (RT3). (**D**) chalkified limestone (RT4), (**E**) sucrosic dolomite RT5, and (**F**) moultic sucrosic dolomite RT6. Figure 7: Composite well logs of E11-2. The logs are digitized and visualized using the software Well CAD. Description of the cores includes grain size, lithology, Dunham texture, gamma-ray, neutron, and density, porosity from core plugs, interpreted lithofacies, microfacies, and environment. **(b) Sequence SS2 Cycle IV**  
In this interval, the gamma-ray shows thin peaks, which again seem to coincide with the few occurrences of dolo-limestones in E11-2. The lower part with high-gamma-ray values consists of coralline red algae and minor benthic foraminifera pack-to-grainstone. There are predominantly mouldic/sucrosic (calcitic) dolomites (packstones to grainstones), with some sucrosic/mouldic dolomites (mudstones to wackestone). The reservoir quality is related to the degree of dolomitization and is generally good, with the average gross porosity ranging from 21% in E11-2 to 21% in E11-1. The reservoir quality tends to be laterally persistent. An overall increase in gamma-ray and density is observed towards the top of the interval, where argillaceous limestones are present (FS3). This increase is also present in E11-3 but can only be explained in the upper part by the presence of an argillaceous interval. **(c) Sequence SS3 Cycle IV**  
The sequence consists of foraminiferal limestone packstones and partially argillaceous lime wackestones with cemented coral fragments. The unit is present throughout the buildup area, with a uniform thickness in the region of 10-15 m.  
The density and gamma-ray values continue to decrease and rise again towards the upper boundary, which is defined at the base of the argillaceous limestone FS4. It is observed in the gamma-ray log that thin peaks are present in the upper half, which coincide with dolo-limestone and dolostone layers, which seem to correlate between several wells. **(d) Sequence SS4 Cycle V**  
An alternation of tight and chalkified or mouldic lime packstones is observed with some reefoid to protect influences in the crestal area E11-1. The average porosity ranges from 8% in E11-2 to 19% in E11-1. We observe in both wells constant gamma-ray values with a slight increase at the top, especially in E11-2. A connection between the occurrence of dolostone and an increase in gamma-ray seems to be present in E11-2.