The casing spool fir drilling and also special designed casingspools based on customer demandes Intermediate casing can seal in the bottom of casing spools,production casing can hung in the upper part of spools; Intermediate casing can seal with 1 or 2 P-type,B-type,FS-type or metallic sealing and conbined sealed; The 45degree shoulder is designed in the upper part,withhigh hanger capacity,wear bushing or test plug can beinstalled for well drilling,tubing can also be hung to meetprroduction requirement; The sealing element of lock screws are designed in the frontend of connections,bolted connections can be equipped withremovable valve plugs; All testing ports and grease fill ports are metallic seal.