Choosing a Reservoir Model

Choosing a probable reservoir model type requires considering of a number of factors including seismic data, geology, log data, and information provided from other wells drilled into the same formation. As well, different models can be used to match a single set of data.

The choice of model can drastically change the outcome of a forecast. For example, pressure transient analysis of radial flow data can be used to find the reservoir flow capacity (kh). If heterogeneity is observed in the data, one might use the composite model with different values for permeability in each zone. Another analyst might decide that using a two-layered multilayer model, having different net pays, is more probable. The forecast of the composite and multilayered models for this situation can differ drastically, even though both models can match the test data. The analyst must decide which model is better.

For assistance in selecting a model, refer to basic model typecurves to help identify which model best represents your pressure response.