Обоснование снижения концентрации кислотного состава при проведении обработок призабойных зон скважин на нагнетательном фонде с 12 до 8 %

Abstract

The substantiation of the application of a new technology for treatment of bottom-hole zone (hereinafter referred to as BHZ) treatment of injection wells with reduced concentration of acid compositions. Maintaining reservoir pressure during field development is carried out by injecting water into the formation in the bottom hole-zone through injection wells, as a result of which, over time, the filtration characteristics of the formation in the near-wellbore zone deteriorate. In order to clean the bottom-hole zone and, as a result, increase the pick-up rate of injection wells, acid stimulation is performed. The article is based on the world experience of treatment of injection wells using 12% acid composition, as well as on the technology of treatment of bottom-hole zones of injection wells of the Northern Caspian fields with 8% acid compositions. Bottom-hole zone treatment technology is applied at all stages of oil field (deposit) development. Bottom-hole zone treatments are carried out based on actual injectivity indicators and/or after geological and technical measures have been taken at the reservoir. LUKOIL-Nizhnevolzhskneft facilities traditionally use 12% acid compositions for treatment of terrigenous reservoirs, which are selected based on the results of laboratory tests for the current reservoir conditions. The BHZ technology includes sequential treatment of bottom-hole zone and down-hole equipment deposits with hydrocarbon solvent, surfactant solution and acid composition. At that, the technology of work execution (sequence, injection speed, quantity of reagents, number of packs, etc.) is determined by specialists depending on the composition and layout of down-hole equipment, physical and chemical characteristics of the formation (thickness, porosity, permeability, bottom-hole temperature, formation pressure, rock composition) and economic evaluation. The article focuses on the principles, technologies and compositions of solutions used in the North Caspian fields.