METHOD FOR CLEANING A WELL FROM A COMPACTED SAND PLUG Russian patent published in 2021 - IPC E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, namely, to methods for cleaning and washing wells from compacted sand plugs. A column of pumping and compressor pipes (tubing strings), equipped from below with a feather made in the form of a cylindrical nozzle with a peak at the end, is lowered into the well to the plug interval. The peak is made flat in the form of a rhombus with a transverse diagonal length equal to 0.9 of the inner diameter of the well. A mechanical effect is produced on the plug until the top layer of the cork is loosened in 3-4 cycles. In each cycle, the weight of the tubing string column is partially unloaded onto the plug, the tubing string column is lifted until the weight of the tubing string column suspension is restored, then the tubing string column is rotated from the wellhead. After mechanical action on the plug, a waste element is dumped from the wellhead into the tubing string column, after landing the waste element on the landing seat of a large hole in the partition, a hydraulic monitoring effect is performed on the compacted sand plug by pumping liquid through the tubing column through small diameter holes located at different distances from the center of the cylindrical nozzle until the compacted sand plug is eroded. In the process of hydraulic monitoring, the tubing string column is simultaneously lowered down with the possibility of partially unloading the weight of the tubing string column on the eroded plug until the current bottom of the well is reached with the liquid rising through the inter-tube space into the channel. The direction of washing is switched and by pumping the washing liquid through the inter-pipe space, the washed-out sand is washed along the pipe column into the channel.

EFFECT: quality of loosening the plug before the hydromonitoring action, the efficiency of the hydromonitoring action and the reliability of the implementation of the method are improved, the probability of damage to the threads along the body of the pipes and in the couplings of the tubing column is eliminated.

1 cl, 3 dwg