A Study of High-baric Gas Cushion Drilling Technology

摘要

During drilling of extended-reach horizontal wells, horizontal drill strings touch the low side borehole due to their gravity, so the friction between drill strings and the side wall is high and weight on bit is provided difficultly, which leads to a low rate of penetration. Considering this, a high-baric nitrogen cushion drilling technology is preliminarily studied, the fundamentals and the construction procedures of a high-baric nitrogen cushion rig are given, and two kinds of special drill pipes are designed. Theoretical analysis indicates that this study can help to reduce the friction and effectively apply weight on the bit, which helps to enhance the rate of penetration.