Killing of Wells is a prompt measure in case of emergency
Killing of wells is a prerequisite for a quality repair of well at any emergency situations.
Works are aimed at preventing the fluid from gushing out of the well with the help of injection of killing fluid, and thus, well killing is performed due to the rise of bottom-hole pressure in excess of the reservoir pressure.
Measures for well killing with special water based fluids, especially repeatedly carried out, impact a negatively on field performance: production decline and increasing of time frame of well completion / bringing the well on to stable production, which can cause significant loss of quantity of produced oil.
Long-term practice has allowed formulating a list of requirements for technological fluid intended for well killing:
- minimize penetration of liquid filtrate and solid particles in the bottom-hole zone of the reservoir;
- ensuring the stability of solutions in contact with brine water;
- easy removal of the filtrate and solid particles;
- exclusion of the interaction between leachate and clay material in the collector layer;
- prevent the formation of deposits in the pore zone of the reservoir;
- fluid injection pressure should comply with the strength characteristics of the casing and wellhead equipment.
So, to preserve, restore and / or improve the performance of wells various modifying additives are introduced into the killing fluid: surfactants (in order to reduce the interfacial tension at the oil), reagents with appropriate water-repellent properties, necessary to reduce the residual water saturation and increased permeability for oil.
Evidence shows that a number of reagents for killing oil wells on the market has ample physical and chemical characteristics to ensure the necessary quality of the work.
Gentle effect on well’s operating parameters is achieved with the help of specially designed modified killing fluids, containing water repellent surfactants, inhibitor and other additives. The use of specialized fluids can reduce the period of bringing the well on to stable production, as well as significantly increase the oil flow rates, including with the help of reducing its water content.
"SNK" LLC company (hereinafter: SNK Company) offers the oil industry execution of works on gentle well killing in the optimum time with minimum cost and high quality.
To improve efficiency of the measures, different methods of killing wells and improve reservoir properties are applied before the main cycle of activities in order to provide temporary isolation (blockage) of the well. SNK company uses СНК-2 blocking hydrophobic emulsion solution (reverse type emulsion having external hydrocarbon phase) of its own production, which do not mix with fresh and brine water.
СНК-2 solution is versatile enough to be effective when used in carbonate and clastic reservoirs operated in a wide range of conditions: a hydrostatic pressure level, as well as in the range of abnormally low to abnormally high formation pressure. It is recommended for use in a reservoir temperatures up to 100C, with main killing liquid with the density 2-3 units lower than the density of СНК-2, the amount of the injected composition is recommended not less than 1 m3 /m.