Study of similarity recognition of drilling parameters in weathered granite formations

摘要

The successful application of the slope-coefficient-searching-identification algorithm (SCSI) in similarity recognition for general granite formations initiates this study in earth-fill granite as well as in intricate granite. Based on the similarity criteria and SCSI algorithm, two case studies were carried out for the similarity between rotational speed of drill bit as well as flushing pressure and effective thrust force graphics in two different types of weathered granite sites. The results show that the similarity coefficients between rotational speed of drill bit as well as flushing pressure and effective thrust force are 0.72 and 0.84 respectively. Although differences between distances of the graphics exist in this study, the curves of both rotational speed and flushing pressure agree with the effective thrust curve in shape, which provides a possible method for identification of various formations by use of similarity between special drilling parameters.