Looks like cementing?
Basically after a well is drilled and the casing string is in place, they pump a ****-ton of cement down the casing. It hits a diverter at the bottom, and forces it's way into place between the hole and the casing. This locks the casing in place. (this is also one of the factors that led to the MC272 blowout...macondo...deepwater horizon..)
So, basically when they call, you guys roll up, set up the pump trucks and run hardlines over to the wellhead, and pump ******' cement until engineering thinks you've pumped enough. Then you rig down, pack your ****, and go off and cement some other well. You will likely work a 12 hour shift (job runs 24 hours a day) and there's probably no set on/off schedule. So that's it. Maintain the equipment, show up, run all the necessary lines and gauges and stuff, and pump. then tear it all down. Repeat.
It's dirty, and land rigs are ****, but it can pay the bills.
PS Schlumberger doesn't actually 'drill' they are a service company. Well, they do drill when it comes time to take the well to a horizontal tangent (they do directional drilling) but they don't have rigs or anything. They're a 3rd party company that provides services like cementing, directional drilling, welltesting, all sorts of stuff. HUGE company. Much profit
Any questions, about any of it, just ask. I set up all the telemetry on the land rigs... Basically installed a megasquirt-like monitoring package that told them what every piece of equipment involved with a drilling rig was doing.
This- Canrig Drilling Technology Ltd. - Instrumentation Rentals