From Sedimentological Concept to 3D Reservoir Models. Case Studies from Offshore Mozambique

Most 3D static models are an effort to represent and characterise the subsurface. Models are not right or wrong but a representation. Attempting to have a fair-minded representation, a 3D static model should have an adequate proportion of deterministic and non-deterministic elements (probabilistic or stochastic) ( Ringrose & Bentley, 2015 ). To obtain a reasonable result, the combination of these elements needs to be balanced. Models driven mainly by geological concepts tend to be unbalanced to the deterministic side. Whereas, it would be unbalanced on the non-deterministic side when the model rely on stochastic algorithms or probabilistic inputs. A balanced combination of deterministic and non-deterministic elements has been achieved in a series of 3D static models built for ultra-deep water turbidite deposits in offshore Mozambique. The result is a model that rely on: a) the geological concept which has been shaped by the integration of an extensive dataset (deterministic component), and b) an extended elastic inversion that allows to understand the areal and probability distribution of petro-elastic parameters (non-deterministic component)