Carbonate petrophysical rock typing: integrating geological attributes and petrophysical properties while linking with dynamic behaviour

Carbonate rock typing provides a vehicle to propagate petrophysical properties through association with geological attributes and, therefore, is critical for distributing reservoir properties, such as permeability and water saturation, in the reservoir model. The conventional approaches to rock typing have significant gaps in incorporating diagenetic processes, transferring rock types from core to log domain, accounting for fractures and using appropriate methodology to realistically distribute rock types in the static reservoir model. The workflow proposed in this paper addresses these issues in a comprehensive way by determination of petrophysical rock types (PRTs), which control static properties and dynamic behaviour of the reservoir, while optimally linking to geological attributes (depositional and diagenetic) and their spatial interrelationships and trends. This approach is novel for the fact that it: (1) integrates geological processes, petrophysics and Earth modelling aspects of rock typing; (2) integrates core and log scales; and (3) provides a flexible 'road map' from core to 3D model for variable data scenarios that can be updated with progressive changes in data quality and quantity during the life cycle of an asset. This paper introduces the rationale behind this workflow, and demonstrates its workings and agility through deployment in two large carbonate fields.