Kuwait has proven conventional oil reserves of about 100 billion barrels which makes it one of the major oil-producing countries worldwide. Most of this reserve is found in Cretaceous and Jurassic with minor quantities in the Paleogene sedimentary successions. Most hydrocarbon production comes from the siliciclastic Burgan Formation which is the most important reservoir in Kuwait. The Jurassic and Lower Cretaceous exhibit good quality source rocks that charged most of the hydrocarbon reservoirs in Kuwait and entered the oil window in Late Cretaceous to Eocene. Most of the hydrocarbon is trapped in very gentle four-way closure structures that are related to the deep-seated fault system of the Arabian Peninsula such as Khurais-Burgan Anticline. Hydrocarbon reservoirs in Kuwait are sealed and capped mainly by shale rocks and to a less extent by evaporites. In the last 15 years, Kuwait Oil Company (KOC) displayed interest in commercially exploiting unconventional hydrocarbon reserves and started laying significant emphasis on the exploration and development of unconventional resources. The aim of this work is to summarize the different petroleum systems of Kuwait including the Paleozoic, Mesozoic, and Cenozoic systems.

The complex of Pleistocene-Holocene sediments in the Al-Khiran area of Kuwait represents a petroleum basin analogue where organic-rich sediments in lagoons are closely associated with porous potential reservoir facies of oolitic beach ridges. The petrography, mineralogy, elemental and organic geochemistry of the carbonate-evaporite successions exposed along the southern coast of Kuwait have been analyzed. The physical and chemical conditions of the depositional environments and the diagenetic history of the sediments have been evaluated.Analysis of sediment grain-size distributions and parameters indicates that the coastal areas near their connection to the open Gulf and at the mouths of tidal creeks are dominated by coarse-grained, moderately-sorted carbonate beach sands, with low amounts of total organic matter (TOC ¼ 0.3 wt%). Landward, at the ends of the creeks, the concentration of ooids decreases, and silt-clayey sediments composed mainly of pellets and calcareous mud interbedded with algal mats are found. This low-energy setting reveals a higher TOC content (0.9 wt%) than the sediments deposited at the mouths of the tidal creeks, indicating petroleum source-rock potential for the tidal creek facies.Pleistocene oolitic limestones consist of elongate, cross-bedded, thinly-laminated ridges of carbonate sand, oriented parallel to the strong tidal currents. The sediments are composed entirely of well-sorted, coarse ooids (0.5 mm diameter). Study of the diagenetic processes and porosity in these rocks shows that they exhibit excellent reservoir potential as a result of prolonged exposure to freshwater leaching.Low amounts of trace metals, low organic-matter contents, and relatively high O/C atomic ratios of the organic matter in the bioturbated beach sediments and ridges, indicate that they were laid down under highly oxygenated open-marine conditions, where current and wave action contributed to the destruction of the organic matter. However, sediments deposited at the ends of the creeks show relatively higher tracemetal and higher TOC contents. The physical and chemical conditions in the creeks allow the preservation of amorphous algal marine-type organic matter, enhancing the source-rock potential of the sediments.