Method for preventing deep-well pump piston from being stuck by sand

The invention relates to the technical field of well control blowout prevention, in particular to a sand blocking prevention method for a piston of a deep-well pump, which comprises the following steps of: 1, selecting the deep-well pump according to the actual liquid supply amount of an oil layer; secondly, a gravity sand prevention pipe is connected between the liquid inlet of the deep-well pump and the tail pipe, and the gravity sand prevention pipe comprises an upper connector, an outer pipe, a center pipe and a lower connector. The device is reasonable and compact in structure and ingenious in conception, oil in an oil well enters the outer pipe and the center pipe through the liquid inlet hole to annularly move downwards, the flow rate of the liquid is increased due to the fact that the space is reduced, and fine sand carried by the oil continuously moves downwards to settle into the tail pipe due to the fact that the density of the fine sand is larger than that of the oil. The oil liquid with small den