METHOD FOR MAKING A BOTTOMHOLE FILTER Russian patent published in 2006 - IPC E21B43/08 C09K8/56 

FIELD: oil and gas extractive industry, in particular, technology for creating bottomhole filters in deep wells cased by columns, opening unstable weakly cemented rocks of collector; possible use in gas and oil deposits, underground gas reservoirs and grounds for industrial drainage disposal; especially useful during major repairs at gas, oil, water-collecting and force wells, operation of which is complicated due to sand flow.

SUBSTANCE: in accordance to method, well is expanded. Limits of filter-adjacent zone are determined in interval of productive bed of collector. Preliminarily, sand plug is washed from well borehole to artificial bottomhole. Technological window is cut in interval of productive bed of collector in filter-adjacent zone with capture of 1-3 meters of thickness of fluid-resistant impenetrable beds with full destruction of body of operation column and cement ring. Then in interval of technological window well borehole is expanded. The latter is expanded to diameter, exceeding internal diameter of operation column not less than 4-5 times. Expanded well borehole is gradually filled with cementing solutions. Into lower section, water-impenetrable cement solution is fed, to middle-main section reinforced penetrable compound is added, and upper section is filled with light cement solution. After hardening of cement solutions, these are drilled up to the artificial bottomhole in sump. Drilling is performed with expansion of well borehole in interval of productive bed of collector up to diameter, exceeding diameter of operation column 2-3 times, but less than well diameter expanded in interval of technological window for 2-3 times the internal diameter of operation column.

EFFECT: prevented collapse of skeleton of weakly cemented rock during well operation.

2 cl, 3 dwg, 1 tbl