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Device for transporting materials across fragile structures
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Method of recovering elements from well bores
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Rotary jar
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Fluid transmission scale
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Outside pipe cutter
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Method and apparatus for cementing
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Method and apparatus for taking samples
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Pipe-pulling machine
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Well cleaning apparatus
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Safety cathead
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Electrical driving machine
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Rotating jar
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Device for unscrewing and withdrawing pipe
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Pipe-engaging slip
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Testing device for oil wells
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Pipe puller
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Pipe puller
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Pump
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Wrench
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Collapsible taper-thread-cutting tool
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