Segmental salvage processing sand prevention pipe column and conversion device

The invention discloses a segmental salvage processing sand prevention pipe column and a conversion device. The segmental salvage processing sand prevention pipe column comprises an oil pipe column, a sand prevention tool, a sand prevention screen tube, a convertible connecting mode safety connector, a flushing pipe column, a connecting rod, a safety connector connecting mode conversion device and a screwed plug. The connecting rod is connected with the lower end of the flushing pipe column and is tripped into the sand prevention screen tube. At least one stage of convertible connecting mode safety connector is installed. The convertible connecting mode safety connector comprises a safety locking spring, a connecting pin, an external body, a supporting lock spring and a lower connector; a boss is arranged inside the supporting lock spring, an external boss is arranged at the lower portion of the supporting lock spring, and milled long grooves are evenly formed in the lower half portion of the supporting lock spring. The safety connector connecting mode conversion device is arranged inside the sand prevention screen tube in advance. The connecting rod is connected with the flushing pipe column and is connected with the safety connector connecting mode conversion device. By means of the segmental salvage processing sand prevention pipe column and the conversion device, salvage processing is prone to being carried out on the sand prevention pipe column in the later stage, the salvage operation period can be shortened, the salvage cost can be reduced, and the segmental salvage processing sand prevention pipe column and the conversion device can be widely applied to oil-gas sand prevention wells.