Vertical and Horizontal Wells

With unconventional reservoir analysis, you can select vertical (single fracture) or horizontal well models. The horizontal well includes two options: effective permeability or matrix. The analysis procedure is the same for both well types; however, the calculation inputs for horizontal well models are used differently.

In the effective permeability model, the SRV Stimulated Reservoir Volume is treated as a region of higher effective permeability, and the horizontal well is treated as a single fracture. The [Le*(2xf)] value is entered and the effective permeability is calculated.

The matrix permeability model considers bi-wing fractures extending from the horizontal well, and the area of the SRV is based on the flowing material balance (FMB) interpretation. When the horizontal well length and number of fractures are provided, the width of the area of the SRV (ASRV) is used to set a fracture half-length (xf) to each fracture. The matrix permeability in the SRV can then be determined from the total fracture half-length. Alternatively, if the matrix permeability is entered, providing a different total fracture half-length, the area of the SRV and OGIP / OOIP in the FMB will be changed to match.

Note:   None of the inputs in the Calculations section are required, but they can provide additional information about the model used for forecasting.