Page 248 - Principles of Applied Reservoir Simulation 2E

Part IV: WINB4D User's Manual 233

23.3 Data Input Requirements

WINB4D input data is divided into two parts: initialization data, and
recurrent data. Initialization data is described in Chapter 24. It includes data that
is set at the beginning of the study and is not expected to change during a model
ran. Such data includes the reservoir description and fluid properties. Recurrent
data is described in Chapter 25 and refers to data that is expected to change
during the course of a simulation. It includes well schedules and timestep control
information. Additional discussion of WINB4D is presented in Part V: Technical
Supplement.
Title or heading records are read before each major and many minor
sections. These records are designed to make the input data file easier to read
and edit.
All input data, with the exception of well names, is entered as free format
data. Two free format data entries must be separated by a comma or a space if
they are entered on the same line.
In many cases, codes are read that will specify the type of input to follow
and the number of values that will be read. These codes increase the efficiency
and flexibility of entering input data.
Input tabular data should cover the entire range of values expected to occur
in a simulation. Examples of tabular data include fluid property data entered as
functions of pressure and relative permeability data entered as functions of
saturation. The linear table interpolation algorithms in WINB4D will return
tabulated endpoint values if the independent variable goes outside the range of
the input tabular values. No message will be printed if this occurs.
If an array of input values must be read, the following input order must
be followed. Layer 1 (K = 1) is read first. The data in each layer are read by
rows, starting with row 1 (J = 1). Values of the array element are read for the
first row starting with column 1 (I = 1) and proceeding to the end of the row
(column I = II). After II values are read, the next row (J = 2) of values are
entered. These values must begin on a new line. This data entry procedure is
repeated for all rows and, subsequently, for all layers until the complete set of
array elements has been entered.