NEW LINER TIEBACK CEMENTING TECHNOLOGY IN HIGH-PRESSURE GAS-OIL WELLS

The new type drilling liner tieback equipment and cementing technology are developed because of the annular gas channeling in high-pressure oil-gas well after cementing. This equipment consists of milling shoe, tie-back sub, choke float collar, millable tie-back stem upper end and cement relict on the inside surface of the equipment. The technology consists of plugging the interval between tie-back liner and the upper casing, preventing the mud outflow at wellhead while set casing and ensuring the enough compression space after the tie-back sub plug in. The field application indicates that the tie-back technology is convenient on operation, and the tie-back assembly is reliable and can endure high-temperature. The equipment has been applied in Sichuan, Shengli and Bohai oil fields and the application results are quite well.