METHOD OF ELIMINATION OF LOWER BOREHOLE ANNULUS CIRCULATION IN WELL Russian patent published in 2008 - IPC E21B33/13 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be employed at elimination of lower borehole annulus circulation - inflow from horizon lying beneath or absorption of pumped liquid by lying beneath horizon. The essence of the invention is as follows: the method incorporates insulation of the lower part of the well from inflow of liquids and pumping of an insulating material. According to the invention the lower part of the well in insulated from inflow of liquid starting at a depth 0.8-1.2 m above lower perforation holes. Temporary insulating material is pumped into an upper interval of perforation left open, this material represents a fringe of stabilised water-oil emulsion; pumping is performed till injection capacity drops to 50-90% from initial. Then insulation is transferred from inflow of liquid into a lower part of the well 3-5 m beneath the lower perforation holes. A plugging material "Granit" is pumped into opened part of the well in two steps. During the first step material is brought to repair interval, then a flow column is lifted above the material "Granite" and a process conditioning is performed till the material "Granite" breaks down. During the second step lower portion of broken material "Granite" is pressed into borehole environment, then reversed washing out, process conditioning for material hardening, acid decomposition of materials of stabilised water-oil emulsion and well development are performed.

EFFECT: upgraded efficiency of method.

2 cl, 2 ex