Page 191 - Principles of Applied Reservoir Simulation 2E

Chapter 18

History Matching

The history matching process begins with clearly defined objectives.
Given the objectives, it is necessary to acquire model input data, especially the
history of field performance. One of the essential tasks of the data acquisition
stage is to determine which data should be matched during the history matching
process. For example, if a gas-water reservoir is being modeled, gas rate is
usually specified and water production is matched. By contrast, if an oil reservoir
is being modeled, oil rate is specified and water and gas production are matched.
Data acquisition is an essential part of model initialization. Model
initialization is the stage when the data is prepared in a form that can be used
by the simulator. The model is considered initialized when it has all the data it
needs to calculate fluids in place. The reservoir must be characterized in a format
that can be put in a simulator and that is acceptable to the commissioners of the
study. Reservoir characterization includes the selection of a grid and associated
data for use in the model. It may also require the study of multiple reservoir
realizations in the case of a geostatistical model study [for example, see
Pannatier, 1996; Lieber, 1996; Rossini, et al, 1994; Englund and Sparks, 1991;
Haldorsen and Damsleth, 1990; and Isaaks and Srivastava, 1989]. All fluid data
corrections, such as flash corrections applied to differential PVT data in a black
oil simulation, must be completed during the model initialization process.
In many cases, simple conceptual models may be useful in selecting a final
grid for the model study, especially when determining the number of layers. As
an illustration, suppose we want to track flood front movement in a very large
field. In this case, we want as much areal definition as possible (at least 3 to 5

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