Most of the gas wells in Western Siberia are on the closing phase of development, characterized by low formation pressure, high water content, destruction of bottomhole zone and other complications. Under these conditions, preservation of the designed volumes of gas production and recovery of technical state of the wells is impossible without well workover.

The well workover at gas and gas condensate fields is always accompanied by well killing. The well killing in underbalanced conditions requires application of the best technologies and thoroughly selected killing liquids and blocking compositions, as during the lack of formation energy the natural self-purification of the formation takes a lot of time.

Well killing in standard conditions is usually performed via production string, packer scheme and cruclation valve, which is opened for the period of circulation.

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