Swirling analysis of drilling strings and anti-whirl stabilizers design

The drill string revolves around both of its axis and the borehole while drilling. The revolving is called swirling. It is harmful to drilling strings. In this paper, on the basis of analyzing the swirling principle of drill strings and the angular velocity of swirling, the structural damage of the currently used stabilizers to the drilling string is analyzed. A new type anti-whirl stabilizer is designed. The main body of the stabilizer can revolve freely to prevent or reduce the drilling string swirling, so as to reduce the damage to the drilling string. From the perspective of the swirling devices, the anti-whirl stabilizer can be divided into the cylindrical roller anti-whirl stabilizer and the sliding bearing anti-whirl stabilizer. The structure and characteristics of the two types of stabilizers are separately introduced, and the correlation analysis between them and the rolling stabilizers. It is mentioned that the anti-whirl stabilizer has such advantages as swirling prevention or reduction. It is also features in reliability and simple structure. It has broad prospect for application.