Make tools, fittings, and small metal pieces used in other products.
Analyzes samples of fluids from specified formations in oil well to determine productivity of strata, using special testing equipment: Assembles valve device and automatic pressure recorder on drilling floor, using handtools. Directs ROTARY DRILLER to lower section of drill pipe containing instruments into well to specified depth. Opens valve by surface control to obtain sample of fluids in valve device and to chart pressure of fluid-giving formation. Closes valve and directs ROTARY DRILLER to raise pipe and equipment. Analyzes chemical content of sample and interprets pressure readings to determine presence and quantity of oil, gas, water, or other materials in formation. May send sample of fluids from formation to laboratory for analysis. May perforate boreholes [PERFORATOR OPERATOR, OIL WELL].