METHODS OF WELL KILLING WITHIN THE SEVERE ENVIRONMENT OF GAS AND GAS-CONDENSATE WELLS Russian patent published in 2012 - IPC E21B43/12 

FIELD: oil producing industry.

SUBSTANCE: invention belongs to the oil producing industry, more specifically, to killing of gas and gas-condensate wells within the framework of well-workover, primarily carried out in productive formations with abnormal low pressure and within the severe environment. Essence of the invention: the production string is filled with sealing composite in the volume equal to the total volume of the production string and the volume of the annular sub-packer space of a well. The sealing composite is pushed into a sub-packer space of a well, gradually pumping the production string with displacement and killing fluid, whereupon the well is left off for return-to-thermal-equilibrium time. After that the completion fluid is pumped into the annular space of a well, pushing out the gas, accumulated in the annular space, and into the completion string leak interval and the upper part of the annular space of a well, where it is gathered in a gas cap and blown off. Subsequently the annular space of a well is filled with a plugging composite with its driving into the completion string leak interval, whereupon the well is left off for about 12 hours. After that the production string upper than the packer and lower than the completion string leak interval is located, through holes are made. Beneath the through holes, from within the production string, a blind plug is placed. He production string is filled with killing fluid, which, while going through holes in the production string, rinses the rests of the plugging composite, displacement and completion fluid from the annular space of a well. The killing fluid supply is ceased, when its density in the annular space equals an initial density.

EFFECT: enhancement of packer well killing security within the conditions of abnormal low pressure and severe environment, more specifically, unpressurized completion string or faulty circulation valve.

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