Well Control Aspects of Riserless Drilling

摘要

Riserless drilling is a term used to describe an unconventional technique usig a relatively small diameter pipe as a mud return line from the sea floor instead of a large diameter marine riser. The scheme also balances internal and external pressures at the sea floor by reducing the internal pressure to make a dual pressure gradient possible. This paper presents basic concepts of riserless drilling and a brief review of problems associated with conventional marine riser drilling for deep water applications. The paper also presents hydraulics, kick detection methods, and well control aspects of riserless drilling with comparison to conventional riser drilling. Other operational considerations are given briefly.