Why drilling coring is not suitable for all wells?

The construction is complicated, the labor intensity is high and the cost is high, which affects the drilling speed. Drilling and coring construction is complicated, labor intensity is high and cost is high, which affects drilling speed. It is not suitable for coring in various formations of the whole well. The small volume and irregular shape of coring caused by explosion impact on the borehole wall are not conducive to the outward transportation of objects.