Industrialized application of valve-type continuous circulation drilling device

The continuous circulation drilling is a major change to the conventional drilling fluid circulation mode. This article describes a detailed study of the principle, advantages and disadvantages of valve-type continuous circulation drilling. The researches of continuous circulation sub, control system and transition system connected to the riser manifold are based on a strict quality assurance system and the field drilling operations. The field test got continuous circulation drilling successes of seven wells, with different circulation medium and different drilling methods, which proving that the device meets kinds of drilling technology requirements. The device realizes the continuously circulating operation of connection and disconnection of the drilling tool joints without pumping off. It can avoid the downhole pressure surge caused by on and off of pump, so the range of ECD can be effectively controlled to keep downhole pressure stable to avoid or reduce the complex occurrence which might result accidents. The continuous circulation drilling device plays an important role in improving drilling efficiency, reducing drilling cost and increasing drilling security to achieve the success of drilling safely, efficiently and economically in all kinds of complicated wells.