Changes

冲击钻井

408 bytes added, 06:34, 23 September 2015
no edit summary
! style="background:#f0f8ff;" | 不足
|-
| valign="top" | - Unlike any other drilling method, percussion can remove boulders and break harder formations, effectively and quickly through most types of earth. 与其它钻井方法不同, 冲击钻井可以去除卵石并击碎更硬的地质构造,快速有效地穿过大多数土地种类。 <br> - Percussion drilling can in principle deal with most ground conditions.一般而言,冲击钻井能够应对大多数地质状况。<br>- Can drill hundreds of feet (one well hand-drilled in China in 1923 was over 4000 feet deep). 能够钻井几百英尺(中国一座1923年手工挖掘的井深达4000余英尺)。 <br>- Can drill further into the water table than dug wells, even drilling past one water table to reach another. 与挖井相比,冲击钻井能深入地下水位更深,甚至可以超过一个地下水位而达到另一个。 <br>
| valign="top" | - The equipment can be very heavy and relatively expensive. <br>
- Especially in harder rock the method is slow (weeks, rather than days). <br>
307
edits