A New Approach in Modeling Hydraulic Fractures and Auto Fractures at Injectors in Full-field Models

Abstract

Realistic simulations of full-field models including hydraulic fractures made at producing and injecting wells, and fractures created automatically, when the bottom hole pressure at injectors exceeds the overburden pressure remains problematic in the most commercial hydrodynamic simulators. The existing software can either provide a very detailed fracture dynamics description for one or few wells with high grid resolution and precise fracture geometries, or provide full-field modeling with many wells and skin-factors used to account for hydraulic fractures. With model grids getting finer resolution it becomes more common to have the fractures half length to exceed the grid block sizes.

In the existing hydrodynamic simulators it is the realistic description of large fractures that remains the most problematic issue. In the absence of adequate modeling solutions the reservoir engineers are forced to come up with a set of unphysical approximations causing significant distortions of model properties and deterioration of its forecasting power. The new technology proposed in this paper is based on building networks of new (“virtual”) well perforations in the model grid blocks intersected by the fracture. With the help of this new approach, reservoir engineers can realistically model fracture dynamics in full-field models with hundreds and even thousands of fractured wells.