Types of Oil Drilling Rigs
o An oil drilling rig is a structure that houses equipment such as the derrick, pipe, drill bits and cables necessary to extract petroleum from beneath the earth's surface. Oil drilling rigs can be either offshore for drilling into the ocean floor or land-based.
Jackups
o According to Rigzone, the most often used offshore, movable drilling structures, called jackups, have bottom supports. The hull or main deck area is supported by columnar or open-truss legs. These units drill up to 350 feet deep.
Two types of drilling equipment are used on jackups. One, the most recent and the most used, is the cantilevered jackup, which has the drilling derrick mounted on an arm extending out from the main deck. These allow drilling to be done with or without platforms.
The other type, the slot-type or keyway jackup, has an opening in the drilling deck with a derrick positioned over it. This type of drilling unit can be jacked up over another smaller structure and drill down through its hull.
Floaters
o Other offshore oil rigs, floaters, or semi-submersible drilling units float offshore on hollow columns or giant pontoons which when filled with water can submerge the rig to the required depth. This type of rig is normally used for drilling Wildcat Wells (new wells) and can withstand rough seas.
Fixed Platforms
o More permanent offshore immobile steel or cement structures, called fixed platforms, house drilling rigs that open new development wells. These large units also house crew and equipment and are connected to the ocean floor. Most of these are found on continental shelves up to depths of 1,700 feet, and because of their directional drilling capacities can be attached to numerous wells up to a five-mile radius.
Complaint Towers
o Another type of offshore drilling rig, the complaint tower, consists of a flexible, narrow tower supported by a piled foundation. Its conventional deck operates both drilling and production, and this sturdy unit sustains lateral forces and deflections in water from 1,500 to 3,000 feet depths.
Drillships
o Drillships, usually built on tanker hulls, have been fitted with drilling devices and are used in deep water for experimental drilling. Dynamic positioning systems keep the ship over the well.
Types of Oil Rig Jobs
o Oil rigs operate 24 hours a day, seven days a week, usually with three or four crews that operate the rig in shifts. Some oil rigs run on eight-hour shifts, others on 12-hour shifts. There are many different jobs be done on an oil rig, including technical drilling, management, mechanical maintenance, security as well as cleaning and catering for the crew.
Drill Crew
o The drill crew usually is made up of five positions. "Roughnecks" work on the floor of the rig and in the mud room, operating machinery and maintaining equipment as necessary. Derrickmen are responsible for running mud-room equipment, including mud pumps and holding pits. Derrickmen are assisted by a pumpman, and both positions undertake roughneck duties as required. The assistant driller supervises the roughneck, pumpman and derrickman, and assists the driller, who is in charge of the drilling operation and who runs the equipment. The driller has a high level of responsibility and expertise. University education is not required, but technical training and experience is for drillers and drillers assistants. As of May 2010, roughnecks could expect to earn about $59,000 annually; pumpmen $60,500; derrickmen $65,000; assistant drillers $72,500 and drillers $86,000.
Deck Crews
o The deck crews consist of five positions. Maintenance roustabouts perform general maintenance duties such as cleaning and painting the rig deck; as of May 2010 they could expect to earn about $47,000 annually in this entry-level job. The maintenance foreman is responsible for overseeing the work of the maintenance roustabouts and earns about $59,000. General roustabouts, distinct from maintenance roustabouts, help guide the deck crane and also help roughnecks on the rig floor when needed; they earn about $54,000. Assistant crane operators are typically experienced roustabouts who have the qualifications to operate cranes, earning $59,000. The crane operator has the main task on deck of operating the crane and of supervising the deck crew. The crane operator earns about $69,500.
Security
o Since a large number of the world's gas and oil reserves are offshore in unstable regions such as the Middle East, Africa and South America, security is a concern aboard oil rigs. Most security guards aboard oil rigs are employees of specialized firms and many are ex-servicemen with significant expertise in security issues. Technology plays a large part in oil rig security, including the use of radar sensors to detect incoming vessels. While the mean annual wage for a conventional security guard in 2009 was $26,430, according to the Bureau of Labor Statistics, security personnel in the energy sector had a mean annual wage of $64,610.
