New gravel-sizing computer package for effective sand control design and evaluation

In this paper the details are presented of a software package which represents a new strategic approach to the selection of an optimum gravel size for effective sand control. The new approach not only considers the formation sand size distribution in the choice of the gravel to use, it goes further to evaluate the response of the probable gravels to operating conditions and the overall effect on the well production capacity. This software package which operates in a DOS `pseudo' Window environment is developed on the premise that the best gravel size selection is a function of not only the formation sand size distribution but also other characteristics such as sand sorting and shape, gravelpack structure which dictates the pack pore throat distribution, and operating conditions and the overall effect on the well production capacity. The design and evaluation tool is made up of: (a). A gravelpack structure simulator (Package 1) whose primary function is to carry out a 2-D/3-D simulation of the gravelpack structure from which the maximum pore throat distribution and corresponding poroperm data and pack structure coefficient are computed. (b). The gravel sizing package (Package 2) which is the main subject of this paper is made up of three distinct but interrelated modules namely, the pack structure module, the bridging efficiency module and the well performance module. The possible gravels to use are selected with the pack structure module which permits history matching of the formation sand size distribution with the corresponding pore throat distribution of select gravels. The bridging efficiency module thereafter evaluates the bridging effectiveness of the selected gravels and the probable gravel is finally selected on the basis of the overall well performance evaluation. Specific case studies have been considered to demonstrate the use of the package.