Reservoir Conformance Control in Oilfields Using Silicates: State-of-the-Arts and Perspectives

摘要

The paper is devoted to overview of conformance treatments using silicates. As shown, the history of the silicate conformance control goes back many decades, but its benefits and field potentials were not really appreciated for a long time. Until now, the different silicate-based technologies have been used more than hundreds times in Hungary, Serbia, Norway, USA, Oman and other countries. Injection of silicates aimed at water shutoff and profile correction in producers and injectors, restriction of gas conning in gas-capped oil reservoirs, blocking of vertical CO2 migration in a collapsed well, water shutoff in reservoirs having extremely high permeability and faults and even improving sweep efficiency in CO2 flooding. Results of pilots and routine application were critically analyzed from different points of aspects. Recently, the advanced methods based on simultaneous application of polymers, urea, humates, nanoparticles, etc. recognizing that the pure silicate gels have some disadvantageous properties under reservoir conditions. Combination of silicates with different chemicals improves significantly the stability, flexibility of such inorganic gels and makes it possible to cure great variety of conformance problems in both porous and fractured reservoirs. The field jobs demonstrate ample examples for outstanding and positive statistics and lessons to learn. In addition, the application of those exclusively environmental friendly chemicals may open new vistas in improvement of well performance of both producers and injectors.