Experimental study on bit side force and drilling tendency in a horizontal well using rotary drilling technique

Key words:  drilling  horizontal well  rotary drilling  bit side force  drilling tendency

Abstract:

An experimental study was conducted to measure the lateral forces on drilling bit in a horizontal well when using a rotary drilling technique. The lateral force of bit can be resolved into an azimuth force and a deviation force, and the drilling tendency can be predicted according to the variations of the two forces. The results show that with the WOB and rotary speed increasing, the variation tendency of the azimuth force and deviation force is different. With the WOB increasing, the variation in the frequency of the two forces is not significant, but the variation in terms of energy is significant. However, the frequency variation of the azimuth force is bigger than that of the deviation force, and the energy variation of the azimuth force is smaller than that of the deviation force. With the rotary speed increasing, the frequency variation of the azimuth force becomes larger, while its energy is almost not affected. Meanwhile, the frequency of the deviation force is not sensitive to the rotary speed, but its energy does. In an actual drilling process, either a lower WOB or a higher WOB is suggested to use in order to avoid the “bit-walk” phenomena. Lower WOB and lower rotary speed can be applied in order to reduce the tendency of well deviation.