Conditioning 3D Object Based Models to a Large Number of Wells: A Channel Example

Abstract

Object based modeling is commonly used for generating facies or rock type models that better reproduce complex realistic geology. A drawback of object based modeling is the difficulty of conditioning to dense data. Object based models have other uses, but their use as training images (TI) has become very prevalent in multiple point simulation (MPS) workflows; however, if the object could be conditioned to dense data, they would be used directly as facies models for complex deposits. The proposed methodology is to consider an object as defined by a set of parameters. Optimization of this object is based on the mismatch with data at the well locations. No gradients are used and any object that can be defined by a finite number of parameters could be conditioned to well data. This does not preclude the use of process based models rather than object based models; in this framework, process based models are more complex, yet fully parametric, models. Four different optimization schemes are reviewed for conditioning. An example of fluvial channels with crevasse splays is presented. Conditioning is considered on dense data up to 100 wells and performs well, requiring seconds to condition.