In recent years, geologists have discovered new oil-bearing lithospheric layer – fractured oil-bearing igneous and metamorphic basement rocks, so interest in foundation as oilfield facilities increased significantly. Analysis showed that oil in 32.5% of reservoirs is confined to granitoid rocks, in 29.0% of reservoirs oil is concentrated in metamorphic rocks, in 14.0% - in carbonates, and in 12.5% - in volcanic formations. Not more than 7.0% of reservoirs are in weathering mantle of penetrative rocks.

Known methods of reservoir structure studying can be divided into external and internal. External methods are based on acquisitions from the land or sea surface, where seismic survey (seismic waves) is a tool of study. Internal methods are based on acquisitions in reservoir itself, where the well is object of study. Innovative well survey technology SOTGDIS (special treatment of thermo-hydrodynamic well studies) enables to identify texture of internal structure for borehole environment in massive reservoirs. This technology is based on data acquired during standard thermo-hydrodynamic well studies and does not require changes in oil production technology and well survey.

Developed technology enables to describe flow geometry in reservoir near-wellbore zone, which significantly improves quality of hydrodynamic simulation and provides additional information for flow analysis. As a result, there is a possibility to build adequate hydrodynamic model and locate remaining recoverable reserves in complex reservoirs such as crystalline basement.

Based on data stored in thermodynamic and hydrodynamic well studies, SOTGDIS developed by the authors enables to determine a variety of new parameters describing internal structure of massive fractured reservoir:

  • Geometrical size of super-fractures (effective length, width and openness);

  • Super-fracture angle;

  • Geometrical size and location of active well zone.

In other words, it is possible to describe flow properties geometry in bottom-hole zone for fractured reservoir conditions.

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