Instability-negative pressure loss model of gas drainage borehole and prevention technique: A case study.

ABSTRACT: The internal collapse of deep seam drainage borehole and negative pressure loss represents a serious technical problem affecting gas drainage. To address this problem a creep model of coal around borehole was established based on the plastic softening characteristics of coal. The final collapse time of the borehole was determined and used to derive the three stages of the borehole collapse process. The model of negative pressure loss in drainage borehole was established according to the theory of fluid dynamics, the model of methane gas flow and the creep model of the coal around the borehole. The relationship between the negative pressure loss of drainage and the change of borehole aperture was derived, thereby revealing the main influencing factors of the negative pressure loss in the bo

SUBMITTER: Qi Q 

PROVIDER: S-EPMC7682895 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature