It will cut down the drilling cycle, cutdown the costofdrilling and improve the quality of bit trajectory.
因此可以缩短钻井周期，降低钻井成本，提高井身质量。
2
But the costofdrilling is high, and the electric or shallow seismic explorations are limited by layer media and have lower precision.
钻探成本高，浅震和电法都存在有层状介质的局限性及勘探精度的问题。
3
In the process ofdrilling, lost circulation can often result in serious drilling accidents, delay the period ofdrilling and increase the costofdrilling.