Abstract
This article is devoted to carrying out and interpreting well tests that reveal carbonate reservoirs with a developed system of conducting macrofractures. Relevance of the issue is due to not only the increase the number of such reservoirs in the structure of hydrocarbon reserves, but generally by domestic companies’ low experience in production from such reservoirs.
It was found out that in the presence of rare and extended natural fractures the traditional model of «dual porosity» is ineffective.
The authors studied more complex numerical model, which assumes the existence of a few fractures of different length in the formation as well as fracture systems that are uniformly distributed in reservoir. The cases where the well was at different distances from the fractures or penetrate fracture system were also considered.
The numerical model parameters were adjusted to the results of core analysis, geophysical studies, logging and the history of the wells production history.
The simulation results revealed that the hypothesis of fractured block structure of carbonate reservoirs correlates well with the results of well tests. The technique of determining the parameters of the fracture system according to the well test is validated. The distance to the nearest fractures and the average size of blocks are determined. It is shown that by the well tests in several wells the direction of extended natural fractures can be determined. This gives an indication of the spatial orientation of fractures and their areal distribution.
The obtained results allow to approach the development of new carbonate deposits more rationally, to plan future wells spacing reasonably, to predict well rates and production profile, to consider the consequences of the well interference by the main fractures.
