Reservoir Characterization of Carbonate Reservoirs Karachaganak, Tengiz, Kashagan

This article presents a study which compares carbonate fields in Central Asia and Southeast Asia, their reservoir properties and petroleum system. The Central Asian carbonate reservoirs in the Pricaspian Basin selected for comparison include Kashagan, Karachaganak and Tengiz. Average porosities are low and strongly influenced by the complex diagenetic history. Permeability is aided by the presence of fracture networks. Burial depths are significant: over 4 km at least. Probably the biggest challenge, however, in the development of these fields is the large concentrations of H2S and CO-. Many of the reservoirs in fields are in carbonate successions, and more than 50% of the estimated remaining proven and undiscovered petroleum resources are in carbonate reservoir rocks.The combined study of rock fabrics and physical properties of reservoir rocks is an important aspect of reservoir characterization, because it directly links the geophysical exploration tools to the reservoir properties. Results of such a study provide a fundamental understanding of the petrophysical responses to geological features and their dynamic changes. The aim is to directly convert the attributes of the physical properties to the geological reservoir parameters.