Optimal Allocation of Bottom Hole Assembly Using in the Construction of Coal Seam Directional Long Drilling

According to the factors analysis of influencing drilling track and the prediction of drilling track,combining the coal seam occurrence features of experimental area,several kinds of angle holding assembly models are designed and tested.The results show that the near-bit of stabilizer and packed hole assembly selected in the test have good straight-keeping function and a certain correcting capacity,which is more suitable for directional drilling.Using different straight-keeping stable compound drilling tools are contribute to control the drilling track.