Treatment Measures for Stuck in Palaeochannel Encountered by Surface Drilling of Jack-up Platform

Surface sticking is one of the complex situations that are easy to occur and need relatively high handling skills in offshore drilling. Due to the soft texture surface and the complex geological deposition of the development of palaeochannel, if the surface sticking treatment measures are not appropriate or not timely, it is easy to cause the complex situation of sticking to further deteriorate, causing more serious drilling engineering problems. In this paper, the operation case of sticking and quick unblocking of ϕ914.4 mm wellbore in a well of EP-X block in the eastern South China Sea is taken as an example. The formation characteristics, wellbore structure, and the specific causes of sticking are analyzed, and a fast unblocking method of running small drilling tools to flush the surface sticking caused by drilling in the palaeochannel is proposed, which has a good guiding role in preventing and dealing with similar surface sticking events.