METHOD TO BLOCK A PRODUCTIVE STRATUM Russian patent published in 2003 - IPC

FIELD: oil and gas extraction industry, technology to damp oil and gas boreholes and temporary damp their operation. SUBSTANCE: invention relates to the oil and gas extraction industry, in particular to damp boreholes and their temporary blocking at realization of their overhaul and underground repairs, and also at putting the boreholes in operation after drilling. The method provides for creation of a strong shield on surfaces of the porous muck and an efficient unblocking of the stratum - collector after termination of the repair works or works on a borehole start-up after boring. The method of blocking of the productive stratum provides for inclusion of the sequential pumping in the bottom hole as a buffer of the blocking liquid - the invert emulsion containing a hydrocarbon fraction, an aqueous solution of sodium or calcium chloride, emultal and chalk, and damping liquids with a density, that is lower than the density of the blocking liquid. In capacity of the buffer and the indicated damping liquid they use an invert emulsion of the following composition (weight %): hydrocarbon fraction - 40-60, the aqueous solution of sodium or calcium chloride - 40-60, emultal - 4, SMAD-4. The blocking liquid additionally contains SMAD and asbestos at the following ratio of components (weight %): hydrocarbon fraction - 40-60, the indicated aqueous solution - 60-40, emultal 4, SMAD-4, asbestos - 3-10, chalk - 3-5. EFFECT: the method allows to damp the boreholes and temporary block them at realization of their overhaul or underground repairs, and at putting the boreholes in operation after drilling. 1 tbl