The technology of the reservoir pressure maintaining is associated with a number of problems related with the development of waterflooding induced fractures formed due to a high injection pressure (waterflooding fractures). One of these problems is the possibility of a breakthrough of the injected fluid into an neighbor well through a waterflooding fracture, which leads to the necessity for shutting down the entire row of injection wells to in case of repair and, accordingly, reduces the effectiveness of the reservoir pressure maintenance. Thus, it is important to understand what factors influence on the fracture merging process.
The article considers the waterflooding fracturing in a sector of the development layout with an line-drive woterflooding system and estimation of the time needed for the merging of several fractures initiated from the adjacent injection wells via mathematical modeling. For the sector of the development layout, a complex analysis of field data was carried out using the well-known approaches (Hall plot, step-rate test, reservoir pressure analysis). Based on the conservation laws of continuum mechanics and the constitutive equations for a poroelastic medium, a numerical model for the propagation of waterflooding fractures is developed. As input data for the model, the characteristic parameters of the field, the location of the wells and the scheme for putting the wells into operation were taken. The numerical simulations show that the process of the waterflooding fracture growth is affected by a complex filtration process between injection and production wells in the sector of development layout. In this case, the relative location and distance between wells plays a significant role. Since the merging of waterflooding fractures impact on reservoir pressure maintenance, then to design this process it is necessary to simulate waterflooding fractures within the framework of a coupled geomechanical and hydrodynamical problem. Numerical simulation makes it possible to evaluate the trend of the dependence of the time needed for waterflooding fractures merging on the distance between wells for a specific well location.
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