Prediction and analysis of build-up rate during sliding drilling

The drilling engineering is facing difficulties in accurately predicting the build-up rate during the sliding drilling operation. First, this research developed the three-dimensional mechanical model of the steering bottomhole assembly (BHA), based on the weighted residual method, and calculated the mechanical load of the bit and friction distribution in the steering BHA during sliding. Moreover, given the build-up characteristics of the tool during sliding, the sliding build-up rate prediction model with a zero side penetration rate and the inversion method of the conversion coefficient were developed. At last, the build-up rate conversion coefficient of a shale gas horizontal well was inverted from its drilling data and this application confirms the precision of the proposed sliding build-up rate prediction model. Besides, the effects of drilling parameters, trajectory parameters, cutting characteristics of the bit, and tool structure on the build-up rate and friction of the tool are investigated. It is shown that during the sliding steering, it is in favor of improving the build-up performance of the tool and the sliding drilling efficiency to properly increase the structural bend angle of the tool, lower the weight on bit, and enhance the side cutting performance of the bit. The findings of this research provide vital references for optimizing the steering drilling parameters, tool structure design, and well trajectory control.