Mechanical Analysis on BHA for Nearly Horizontal Directional Drilling in Coal Mine

摘要

Nearly horizontal directional drilling for gas drainage is promoted by some large coal mining enterprises in their high gas mine in our country.It is an advanced technology at present. The drilling trajectory control is one of the key links of this technology.In order to realize the control of the drilling trajectory accurately, mechanical analysis on bottom hole assembly (BHA) and solving are required, the purpose of which is to calculate the deviation force and the azimuth force. This paper expounds the characteristics of nearly horizontal directional drilling of coal mine, establishes the mechanics model and the mathematical model of BHA and then gives the method of solution.