508 mm casing tieback technology on jacket in oilfield development

As the drilling development growing fast in recent year, The operating plan of semi-submersible drilling platform pre-drilling and then fixing jacket topside for tieback completion job is adopted to save drilling rig resource and drilling cost in part of sea area which is base on meeting the requirement of putting into production. For casing tieback and building up fluid channel before completion job, the plan is fixing jacket topside in a short-term after pre-drilling job is accomplished successfully. Base on the idea of saving drilling rig resource, we had finally finished tieback completion job through many investigation and research in Wenchang oilfields. The outer layer of jacket tieback job is 508 mm casing. The procedure of tieback job including joining and fixing centralizer, bore, wellhead, locking tieback and so on. Pressure test should be done for proving the tieback job is successful. It should be considered that the effect of wellhead seal and load carrying ability can meet the needs of long production. By means of the load analysis of casing strings and field cutting technology in Wenchang oilfields, we had made an achievement of more than 20 wells tieback job. It settled the base before putting into production. The accuracy rate of jacket installation have effect on casing strings obviously, it should be tightly controlled in the follow-up oilfield job.