METHOD TO REDUCE WATER INFLOW IN PRODUCTION WELLS WITHOUT LIFTING OF DOWNHOLE PUMPING EQUIPMENT Russian patent published in 2017 - IPC E21B43/32 E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method involves injection of the gel forming composition into the formation through the annular space of the well left for maintenance and downhole pump change. The selective isolation operation is made simultaneously with well killing. Pumping is initially made with an open swab valve and with borehole fluid circulation through the well tubing to the manifold. After the gel forming composition reaches the borehole pump receiver, the swab valve is closed and the pumping is continued into the formation. After the gel forming composition, a saline solution is pumped into the formation with a relative weight necessary to kill the well. Upon the saline solution reaches the perforation interval and the required swab, saline solution, is injected into the formation, the valve opens, and saline solution injection of into the well continues with its circulation through the tubing to complete displacement of borehole fluid into the manifold.

EFFECT: method improves selective isolation conditions, especially in the conditions of reduced formation pressure by preventing the well-killing fluid absorption in preparation for the well servicing.

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