Application and innovation of subsea wellhead tieback technology in marginal oilfield development

Sub-sea wellhead tieback technology is a special technology of offshore drilling engineering.In order to decrease production cost and increase development benefits applying the wellbore of temporary abandonment well to tieback the sub-sea wellhead and building small production platform is a good way.Well BZ34-3-2D was drilled in 1988 and was temporary abandoned but the sub-sea wellhead was kept.This paper introduces the tieback technology and the difficulties using the technology in BZ34-3 oilfield.Through the improvement and innovation of the tieback technology the underwater video was applied to observe the subsea wellhead at last, the tieback was successful which can guide the sub sea wellhead tieback for the future.