Types of Oil Drilling Rigs
Getting down to the basics, there are several types of offshore oil rigs designed to work in a variety of locations, on certain kinds of wells, and differing environments:
Jack ups are moveable drilling structures with bottom supports. Jack ups have open-truss or columnar legs in support of their main deck or hull area.
Platforms cannot be moved like Jack ups. They are immobile. Platforms are typically made from steel or cement and are used to drill new development wells.
Semisubmersibles drilling units, or Floaters, stay afloat offshore on giant pontoons or hollow columns. When filled with water, the pontoons or columns will partially submerge the unit to a desired depth. Floaters are reliable in rough seas and most frequently used for drilling new wells Wildcat Wells.
What exactly is a drilling rig?
Most rigs rely on several primary systems to get the job done:
A hoisting System, often referred to as the derrick or draw works.
A drive group comprised of motors, chains and compounds.
A circulating system of pumps, a kelly, drill string, return lines, and pits.
Well control equipment
Wells are drilled for a variety of purposes. When a new well is drilled in an effort to find new reservoirs it’s called an exploratory well. There are also development wells, which go into already proven oil fields and are designed to maximize oil production from that field.
The most common drilling technique is rotary drilling. It is a method whereby a rotating drill bit is forced downward into the earth to make a hole or wellbore. The drill bit is connected to and rotated by a drill stem, which also provides a passageway through which the drilling fluid (mud usually) is circulated.
A petroleum engineer or expert in the field of drilling could write volumes on the topic of drilling. We just want to give you the basics on Job Monkey.
We’ve talked about the types of rigs, wells, and told you that the most common type of drilling is done by rotary drills. Here’s some information about the way wells are drilled. It’s not always a case of ‘straight down.’
When you hear that a well will be drilled conventionally, it means the well will be drilled straight down vertically to the oil.
Conventional drilling doesn’t always yield the best results. Oftentimes the driller will go down vertically and then make a sharp horizontal turn. Special drill bits are required for this to work. Sometimes there will be two wellbores drilled, one over the other in fairly close proximity. Steam will be injected from above into the overhead hole which forces oil down into the lower hole facilitating easier extraction.
Slant or directional drilling is when the bit goes down at an angle. We hear about this technique more and more due to environmental concerns. Let say the oil is in a sensitive area. You could build your rig on a less sensitive area and drill at an angle until you’re underneath that sensitive area. You get the oil without disturbing the environment so much. Multiple angled holes may be drilled from one rig to maximize production from the reservoir. With the type of equipment and technology available today, directional drilling is very precise.
Offshore Oil Platforms
Offshore oil wells handle the task of recovering crude oil reserves from lake beds and ocean floors alike. The world’s first offshore oil rig was built in 1869, the same year that designer T.F. Rowland patented his offshore rig design.
Offshore Oil Platforms are Located Over Large Bodies of Water
Rowland’s concept resembles modern offshore drills, but his designs were used only in shallow waters. Developments in offshore technology wouldn’t allow for deep sea drilling until after World War II. In 1947, deep water drilling began in the Gulf of Mexico, which remains one of the primary offshore sites today. On a global scale, there are more than 1,000 offshore rigs.
Offshore oil drilling is a successful enterprise, with a variety of oil rig jobs including driller, shakerhand, toolpusher, floormen, ballast controlman, barge engineer or rig welder. Offshore oil wells are sometimes the only crude oil production that a country has. Improved technology has made it possible to extract oil from much greater depths. This is welcome news when considering that shallow water reserves are slowly being depleted.
Offshore Drilling Platforms
For offshore drilling, it is crucial to construct a platform to maximize the drills’ extraction, while at the same time ensuring the safety of the workers by compensating for the water’s natural movement. When the drills are in operation, there is a subsea drilling template that connects the underwater well to the floating platform
The subsea template is floated to the sea floor from the platform where it digs a small hole in the ground to “bury” itself into the seafloor. It remains connected to the platform through several elastic cables, which allow the drilling platform to sway while the subsea template remains anchored. Another component of offshore rigs is the blowout preventer, which is basically a large valve on the offshore rig that prevents oil from spilling out of the drill and mixing with water. The blowout preventer is operated by a blowout specialist. The piece called the “marine riser” extends from above the blowout preventer onto the floating platform. The marine riser is the center piece in a closed circuit system that acts as the transport for liquid from the sea floor onto the drilling vessel. Inside the preventer is the drillbit and drillstring. It is essential that the preventer be strong, yet flexible enough to adjust to the drill platform’s movement.
Like onshore drilling, offshore drilling employs rotary drilling as its primary means to unearth crude oil. Rotary drilling is not much different that drilling that you would do around your house, it is only conducted on a larger scale. The idea is to cut into the earth using Steel Tooth Rotary Bits or diamond studded drill bits to reach the reserve. Once the reserve has been drilled, the product can be removed and sent to the refinery for processing.
Advances in drilling and production technology have increased the possibility that offshore platforms can be controlled from an onshore location. Including a function to control the automatic shutoff that will minimize pollution.
Offshore Oil Rig Jobs
Life on an offshore oil rig is very different from life on an onshore rig. Workers on offshore rigs need to be smart and savvy and aware of the risks involved. In places like the Gulf of Mexico, tropical storms and hurricanes are just a sample of what can go wrong. Offshore oil rigs basically function as a small floating city. Their sizes range from small rigs to rigs that have platforms whose size rivals football fields and whose derrick height rivals skyscrapers.
Even with the apparent dangers of storms and hazardous seas, life on an offshore oil rig can be a welcoming challenge with huge rewards. Most jobs on offshore oil rigs start out at $45,000 a year and could potentially rise up to $100,000+ a year. Workers stationed on rigs that are located miles from shore are housed on barges that are attached to the offshore platforms or in units that are built right into the rig. Life on these offshore rigs does resemble onshore life in some aspects. Workers are reasonably accommodated with showers, food, TV, phones and laundry facilities, but workers should prepare to get familiar with the employees that are around. They may be the only human contact for two or three weeks.
The work schedule on an offshore rig is almost a set routine. Workers offshore are typically on the job for 12 hours a day for seen straight days before they are given a weeklong break back on shore. Some rigs, however, require that their workers operate in two or three week shifts, which means two or three weeks of 12 hour days on the rig followed by two or three weeks off the rig. Workers do need to work a night shift occasionally to maintain the rigs 24 hour operation. While on the job, workers are required to wear hard hats, safety glasses, coveralls and safety boots. Interestingly enough, smoking is not banned on offshore oil rigs, but smokers must be careful to smoke only in the designated areas to avoid any explosions.
The offshore rig offers a unique commute experience. On rigs that are only a few miles from shore, a quick ride on a barge is all that is needed. However, on some Gulf of Mexico oil rigs located more than 20 miles from shore, a helicopter is required to reliably and safely transport workers to their destination.
Perhaps above all, it is important for an offshore oil rig worker to have a good attitude. You will be working with people in very close quarters, and even the smallest disturbance between workers can have implications for the entire rig.
Drilling Rig Rentals or Purchase
Our rig rental services supports customers worldwide.
One of the activities of Soha Europe Invest Company is leasing drilling rigs. We have nearly a quarter century of experience in different fields such as leasing drilling rigs. Our quick application process and lightning fast approval time will allow you to get the drill rig you require, and keep you exploring deep within the earth. Contact Soha Europe Invest Company today to learn more.
Why Drill Rig Rentals
A good way to build up your business and get the next level of job is to rent the equipment first. Prior to investing in a drill rig, most new comers rent a drill rig. You get paid for one or more drilling contracts and now you can invest in your own drill.
The same process can be used for upgrading. Drill rig rentals allow you to use the drill rig you are considering purchasing in the field. You can evaluate how it performs and still possibly profit from renting over buying if you are using a larger drill than you own for a larger, more profitable job. In either case, you can gain experience with the drill rig and make informed decision using a rental drill rig.
Buying a Used Rig
When it’s time for a new rig, and you know that you can’t afford a new rig, it’s time to start looking around the used market. There are a ton of rigs out there on the market — some good, some not so good — so we're going to try to give you a few pointers on what to look for when you go rig shopping. We consider the actual size rig you will need. Make an honest appraisal of the depth and size of the holes you typically drill, and match the rig to the job. We consider the best price and requirements that best suits you. So contact Soha Europe Invest Company today to learn more.