An oil rig was built just for this film, this rig is located in Chalmette, Louisiana where filming mostly took place. Director Peter Berg claimed it was one of the largest practical sets ever built; constructed of 3.2 million pounds of steel in a 2,000,000 gallon water tank.
A lot of oilfield workers in the Gulf of Mexico were against the making of the film, because they felt that it could dishonor the men who died during the actual event. However, Mike Williams (one of the survivors) was all in for the film, and worked on it with the crew, along with another survivor of the event. He felt it was a good way of showing people the circumstances that the crew members went through, and that the goal of the film crew was to make it look as real as possible.
The producers of the movie contacted Mark Wahlberg and told him they wanted a screen combo with an older and younger male lead together. Wahlberg started to contact some of the older actors he knew, like Jack Nicholson. But to his surprise, the producers wanted Wahlberg to be the older lead, with someone like Dylan O'Brien being the younger one.
Graham McGinnis, who plays the Coast Guard Lieutenant, is an actual active duty Coast Guard Helicopter Rescue Swimmer stationed at USCG Airstation New Orleans.
A layman's description and example of the Cement Bond Log, a.k.a. CBL; upon landing on the rig, the OIM (Mr. Jimmy) asks the departing logging crew if they completed their CBL/VDL run. The logging engineer shrugs and proceeds to board the helicopter. Shortly after, the OIM confirms with the BP Well Site Leader, or "Company Man," that no CBL was run. The CBL is used to verify the casing to cement and formation to cement presence and its "bonding" to the casing and to the formation. A "sonic" logging tool is lowered into the well, all the way down towards the zone of interest. The tool is then activated and slowly pulled out of the hole. When energized, the "sonic" transmitter sends acoustic pings around a 360 degrees motion, and detectors placed at various distance in the tool "listen" for the return of these pings, monitor the time it took for the ping to return and how much it was attenuated by the presence or not of cement. Take a large rimmed glass (any glass will do though) and put it in an empty sink with the drain plugged. Flick your fingers at the top of the glass rim, and listen for the sound. Fill up the sink around the glass, and once the glass is immersed in the water, repeat the finger flick. Listen for the sound difference. Now imagine the glass is the casing, and the water is the cement, and you have pretty much understood what a CBL tool does. Of course, this is a very simplistic representation of the log principle as there are more variables to be accounted for, but at least now, you have a better idea of how it works.
Trace Adkins: as the large, angry man looking for his son. Prior to becoming a professional singer, Adkins was an oilfield worker for Global Marine/Transocean.
Peter Berg: as Mr. Skip, one of the guys in charge of running the cement test. He is the character Mr. Jimmy talks to after landing and getting off the helicopter.