Can prolong production period of oil wel

The utility model discloses a can prolong production period of oil wel, , its characterized in that: including main go -between, kelly, tractor, the top welding of kelly has flat joint, flat joint links to each other with main go -between through first go -between, the tractor draws connector and main go -between and links to each other through hanging, hang and draw the connector and include that four are detained second go -between even in proper order mutually, through tractor traction connection drilling rod, the tractor is including hanging piece and traction connection spare, traction connection spare links to each other with hanging through the bolt, it constitutes by U type rings with rather than fixed bottom plate as an organic whole to hang the piece, the bottom of traction connection spare is opened flutedly, through recess joint jointed rod. The utility model discloses a when promoting the kelly and the promotion of traction connection drilling rod, reduced the promotion of a kelly, just once can