Introduction to this special section—reservoir modeling

Abstract

Reservoir modeling is a very generic term whose definition has changed with time, as evidenced from the variety of papers submitted for this special section. Reservoir modeling can be completed deterministically (as was done in the past) or computed probabilistically. Historically, the geologist and the geophysicist created their own “models” which were subsequently merged to create a common idea about the prospect, field or basin. During the early 1980s, it was common to attempt to integrate the disciplines with the hope that the final reservoir model would also be integrated to contain both log and seismic data. Companies eventually began to concentrate the disciplines into a team environment in an effort to integrate their data. In the late 1980s and early 1990s, geologists and geophysicists became somewhat generic in that one geoscientist (interpreter) created the reservoir model which incorporated both the geologic and geophysical data. Today, there is an effort to continue this integration of data, mathematically. We now understand that the “reservoir model” should contain well data (porosity, permeability, water saturation, facies, etc.), production data, seismic data, core analysis, conceptual ideas where the data are unknown, and any other information that will add to the understanding of the prospect, field, or basin. Mathematically integrating these data is not easy due to the scale differences and the availability of data from various sources. An ideal reservoir model, if it could be achieved, would contain all conceivable information about the area but would also contain all the information that is not known. In other words, the model would contain uncertainties at each cell describing what is unknown about the area in a statistical manner, predicting the P10, 50, and 90 of the reservoir. Geoscientists, who have been asked throughout their career to be definitive and to “recommend” the well locations with …