METHOD FOR ELIMINATING FREEZING AND CONTROL WELLS WHEN INSTALLING MINE SHAFTS USING HYDROJET TECHNOLOGY AND A SYSTEM FOR ITS IMPLEMENTATION Russian patent published in 2022 - IPC E21B43/114 

FIELD: mining industry.

SUBSTANCE: invention relates to the mining industry, in particular to a method for eliminating freezing and control wells when installing mine shafts using hydrojet technology. The claimed method includes perforation of wells with a solution on an abrasive made of cement. Lowering the perforator into the well to a predetermined depth and perforating the casing pipe of the well and filling the annulus with a water-cement mixture. Perforation of the casing pipe of the well is carried out by a hydrojet method, and filling of the annulus with a water-cement mixture using low-pressure injection. The process of liquidation of wells is carried out in a sequence of stages. A pumping unit and a mixer are installed on the surface. Before the hydraulic monitor is lowered for a given interval, the freezing or control well is templated and the wellhead is tied with fittings that make it possible to collect the borehole fluid in the freezing gallery. On the cable, a hydraulic monitor is lowered through the existing freezing column to a level above the final depth of the well, during the descent of the hydraulic monitor, a flexible hose is attached to the cable to supply cement mixture, mortar. Hydro-perforation is carried out with 2-4-hp pumps, providing a flow rate of 200-260 m/s from the perforator nozzles with a pressure drop of 18-22 MPa on them, pumping a cement mixture containing 750-1000 kg of cement per 1 m³ of liquid. 0.5-1.5 minutes are spent on processing one interval of the formation, after which the pumping of the mixture is stopped, and the flexible hose together with the hydraulic monitor is lifted being set at the next interval, after which the perforation process is repeated. After cutting the upper holes of the formation in the freezing or control well, the perforator with a flexible hose is lifted to the wellhead. The flexible hose is flushed with an outflow through the wellhead. The wellhead is sealed, cement mixture and mortar are injected into the formation through the head, through perforations. Cement setting lasts 2-3 hours. The flexible hose with a hydraulic monitor is repeatedly lowered to a mark that is 2-5 meters above the perforation interval, and the well is flushed in order to extract the cement mortar distributed above the liquidated formation interval. The flexible hose together with the hydraulic monitor is lifted being set at the next interval. All stages of the process are repeated in relation to all wells, making a movement in a circle. A system has also been announced for the elimination of freezing and control wells when installing mine shafts.

EFFECT: filling the well cavity with cement mortar, ensuring its continuity and stability of the surrounding soil mass.

2 cl, 3 dwg