Gas Drilling Cuttings Breaking on Return
More cuttings producing in higher penetration rate of gas drilling are usually in the larger non-uniform size at the bottom and in the smaller uniform size back to the wellhead. It is indicating that cuttings in the well should be appeared in the successive breaking in the process of upward migration. According to the particle broken theories, the successive breaking phenomenon were analyzed, and given the calculating method for the probability of secondary impact crushing, and applied the breaking process matrix and the particle size distribution function to the cuttings migration crushing in the whole wellbore. The calculating results show that the cuttings in the wellbore are broken by the uneven size volumetric fracture progressively turned into the surface fracture of the uniform process, and ultimately stabilized the small size distribution.
Z. X. Zhu et al., "Gas Drilling Cuttings Breaking on Return", Applied Mechanics and Materials, Vols. 90-93, pp. 151-156, 2011