Drilling Rig Derrickhand or Derrickman A drilling rig derrick hand is responsible for assisting the driller and mud engineer with operations on an oil rig. In this job, you guide the pipe as your team connects it to the drill hole, mix the drilling fluid, or “mud,” and repair and perform maintenance on the rig and associated equipment like the circulation machinery. You keep the pit area, mud house, walkways, and other areas of the rig clean, well-organized, and clutter-free, and your duties and