TABLE OF CONTENTS The flow 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 used by a simulator. Reservoir characterization includes the selection of a grid and the distribution of reservoir properties in the grid. It may also require the study of multiple reservoir realizations in the case of a geostatistical model study [for example, see Chambers, et al., 2000; Kelkar, 2000; Deutsch and Journel, 1998; 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 must be completed during the model initialization process. Another aspect of model initialization is equilibration which depends on the definition of the grid, and is the point at which fluid contacts are established and fluid volumes are calculated. Each of these topics is discussed below.
Flow model grids may be defined in several different ways. Several authors discuss different types of grids, including Aziz [1993], Verma and Aziz [1997], Heinemann and Heinemann [1998], Ertekin, et al. [2001], Dogru, et al. [2002], Carlson [2003], Mlacnik and Heinemann [2003], and Mlacnik, et al. [2004]. Definitions of grid coordinate system orientation vary from one simulator to another and must be clearly defined for effective use in a simulator. Reservoir grids can often be constructed in one-, two-, or three-dimensions, and in Cartesian or cylindrical coordinates. Horizontal 1-D models are used to model linear...
