Changes

* Control and measurement

* Control and measurement

[[file:land-rigs_fig1.png|thumb|{{figure number|1}}Components of a typical land rig: (1) crown block, (2) mast, (3) monkey board, (4) traveling block, (5) hook, (6) swivel, (7) elevators, (8) kelly, (9) kelly bushing, (10) master bushing, (11) mouse hole, (12) rathole, (13) backup tongs, (14) makeup tongs, (15) drawworks, (16) weight indicator, (17) driller's console, (18) dog house, (19) rotary hose, (20) accumulator unit, (21) pipe ramp, (22) pipe rack, (23) substructure, (24) mud return line, (25) shale shaker, (26) choke manifold, (27) mud-gas separator, (28) degasser, (29) reserve pit, (30) mud pits, (31) desilter, (32) desander, (33) centrifuge, (34) mud pumps, (35) dry mud components storage, (36) water storage, (37) engines and generators, and (38) blowout preventer stack. (From IHRDC.)]]

[[file:Land rig example drawing.png|thumb|{{figure number|1}}Components of a typical land rig: (1) crown block, (2) mast, (3) monkey board, (4) traveling block, (5) hook, (6) swivel, (7) elevators, (8) kelly, (9) kelly bushing, (10) master bushing, (11) mouse hole, (12) rathole, (13) backup tongs, (14) makeup tongs, (15) drawworks, (16) weight indicator, (17) driller's console, (18) dog house, (19) rotary hose, (20) accumulator unit, (21) pipe ramp, (22) pipe rack, (23) substructure, (24) mud return line, (25) shale shaker, (26) choke manifold, (27) mud-gas separator, (28) degasser, (29) reserve pit, (30) mud pits, (31) desilter, (32) desander, (33) centrifuge, (34) mud pumps, (35) dry mud components storage, (36) water storage, (37) engines and generators, and (38) blowout preventer stack. (From IHRDC.)]]

==Power system==

==Power system==