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冲击钻井

111 bytes added, 04:37, 23 September 2015
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[[Image:Weighted drill bit.jpg|thumb|right|200px| 负重的钻头]]
Percussion drilling is suitable for unconsolidated and consolidated formations: Sand, silt, stiff clays, sandstone, laterite and gravel layers.冲击钻井适用于下列疏松或固结的构造:沙、淤泥、硬黏土、砂岩、红土和砾石层。
Manual percussion drilling is generally used up to depths of 25 meters.
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