Concentric double-pipe hierarchical injection pipe column

The utility model relates to a concentric double-pipe hierarchical injection pipe column which is characterized by comprising an inner pipe column. A subsurface safety valve and a location joint are arranged on an upper portion of the inner pipe column, an isolation seal assembly is arranged on a lower portion of the inner pipe column and inserted into an isolation packer internally settled with a subsurface sleeve, a big-end-up outer tapered pipe column is arranged outside the inner pipe column, a production packer positioned between the subsurface safety valve and the location joint is arranged between an upper portion of the outer pipe column and the inner pipe column and settled between the outer pipe column and the inner pipe column, an annular safety valve is connected onto the production packer, a seal assembly is connected with a lower portion of the outer pipe column and inserted into an upper packer internally settled with the subsurface sleeve, and the subsurface safety valve and the annular safety valve are connected with a hydraulic control system of a well head respectively through a hydraulic control pipeline. The concentric double-pipe hierarchical injection pipe column can be widely applied to operations of water injection and polymer injection of offshore oil exploitation.