Site and Operational Planning
What the exam tests
Planning a drill rig job before the rig moves: site access, ground conditions, underground and overhead hazards, layout, and contingency planning. The exam expects planning decisions to be tied to actual rig reactions and site data, not rules of thumb.
Core rules
- Site survey: identify buried utilities (call 811 before digging), overhead lines, slope, soft ground, adjacent structures, traffic, and escape routes. Mark exclusion zones for rotation and travel.
- Ground bearing: use geotechnical data or proof rolling. One outrigger or crawler pad can impose far more than the carrier's gross weight divided by four. Use the manufacturer's maximum reaction.
- Access: verify bridge and road load limits, gate widths, turning radii, and pad location. Route survey is part of planning.
- Weather: establish wind, lightning, heavy rain, and frozen-ground stop-work thresholds.
- Operational plan: sequence, spoil placement, casing and fluid containment, communication, and emergency assembly point.
Worked example
A rig's manufacturer lists a maximum outrigger reaction of 60,000 lb. The soil is compacted sand with an allowable bearing pressure of 2,000 psf. Required pad area = 60,000 / 2,000 = 30 ft². A 6 ft × 6 ft pad gives 36 ft², so it is adequate if the pad is centered and rigid. Using the 80,000 lb rig weight divided by four would understate the reaction and under-size the pad.
Traps
Using total rig weight divided by four; ignoring dynamic or impact reactions; trusting “it looks hard” instead of soil data; placing spoils where they surcharge the pad edge; missing overhead lines because the mast is not yet raised.