The drilling rigs used in shale development are usually "top-drive" rigs that are capable of "walking" short distances (on the order of 20 feet) in order to drill multiple wells on one well pad without the need to dis-assemble and re-assemble the rig between each well.
[pdf] It contains averages of rigs running in Louisiana divided into regions: north, south inland land, south inland water, state offshore and OCS. The main source of this data is Baker-Hughes drilling statistic.
[pdf] The DTH drilling rig (down-the-hole drilling machine) is a kind of drilling machine, which is mainly used for drilling in rock formations. The down-the-hole drilling rig uses the impactor and the DTH drill bit.
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