APPARATUS AND METHOD FOR MANAGED PRESSURE DRILLING

摘要

A drilling system employing a main tubular having a plurality of fluid inlet and outlet conduits positioned thereon and a concentric inner tubular having a plurality seals for sealing the annular space between the concentric inner and main tubulars. The fluid inlet and outlet conduits work in cooperation with the annular seals to selectively open and close for effective management of pressure within the tubulars.