Organic geochemical evaluation of hydrocarbons in Lower Cretaceous Middle Minagish reservoir, Kuwait

• Heterogeneous oil in Minagish oolitic belongs to the same family.
• RE6 economic application.
• Heavy oil intervals in the oil column may be found at different intervals and not only at present oil water contact.

Organic petrography and geochemical analyses of 72 core samples from the Minagish Formation revealed vertical variations in oil composition between four wells from the Burgan, Maqwa, Minagish and Umm-Gudair fields. The Burgan Field has a homogeneous oil column while variations in oil column were recognized between fields. The thickest heavy oil column, 46 m, was identified in Minagish Field. GC and GC-MS of the light and intermediate parts of the oil indicates a similar oil type, with a common oil pool in all of the oil fields. Thus, the variation in the nature and distribution of the heavy fractions of the oil in the Minagish reservoir is not be related to the source rock, expulsion and/or oil migration, but related to changes that occurred after or during oil accumulation in the reservoir.The methods and the results of this study are useful for planning drilling specially in reservoirs with heavy oil intervals such as the Minagish reservoir.