Local Update of Object-based Geomodels (SPE-113532)

摘要

Aconsistent method for local updating of object based facies models by further development of already existing software will be presented.An existing facies realization is adjusted to match new well observations by changing objects locally or adding/removing objects if required. Parts of the realization which is not influenced by new wells are not changed. It is also possible to rerun the model only within a specified area, leaving the outside area unchanged or with minimum change due to new wells. Then all objects with reference point inside the area can be changed or removed, and new objects can be added. Model parameters can be changed within the local change area, such that for example object size and intensity can be different inside and outside the area. Alocal update will be applied when a realization from a stochastic geomodel has been history matched and proves to match well with production data. New well observations included in the model will typically not match the objects in the old realization. Due to the good match already achieved, it is not desirable to make a new realization from scratch based on the new well since the history matching process then must be repeated. What is needed is only minor changes of the realization around the well such that new well observations are correctly conditioned, without disturbing the other parts of the realization. The effect of the local update both on fluvial channels passing through the whole reservoir zone and geological bodies of general shape and limited size will be demonstrated on synthetic data. Local update contributes to a more efficient history matching process.