Drillers in this unit group operate mobile drilling machines to bore blast holes in open-pit mines and quarries and to bore holes for blasting and for building foundations at construction sites. Blasters in this unit group fill blast holes with explosives and detonate explosives to dislodge coal, ore and rock or to demolish structures. They are employed by mining, quarrying and construction companies and by drilling and blasting contractors.

Oil and gas well drillers and well servicers control the operation of drilling and hoisting equipment on drilling and service rigs, and direct the activities of the rig crew under supervision of the rig manager. Oil and gas well loggers, testers and related workers operate specialized mechanical or electronic equipment, tools or instruments to provide services in conjunction with well drilling, completion or servicing. Workers in this unit group are employed by drilling and well service contractors, petroleum producing companies and well logging or testing companies.

Oil and gas well drilling workers operate drilling and service rig machinery as intermediate members of the rig crew. Oil and gas well services operators drive trucks and operate specialized hydraulic pumping systems to place cement in wells or to treat wells with chemicals, sand mixtures or gases to stimulate production. Workers in this unit group are employed by drilling and well service contractors and by petroleum producing companies.