Mobile Drilling PlatformMobile drilling platform is being used in the exploratory drilling, to drilland to find out if there’s oil and then move on to the next site. Mostly,the oil company didn’t have the mobile drilling platforms. Since it ismore cost effective to hire expertise and equipment needed than to keepit under their roof.The expertise in here refers to the drilling contractor and the servicecompany like Transocean, Schlumberger, Pride, Frontier, and Sea-Drill.There are 5 varieties of mobile drilling platforms: drilling barge, jack up,semi-submersible rig, submersible rig, and drill ships.
Drilling Barge Mostly used in the swamps or coastlines, the drilling barge has a specification of work about less than 7 meter of water depth.
Jack up drilling rig Jack up oil rigs are limited to shallow water drilling (typically < 300 feet). A jack up typically has 3 or 4 long legs (up to 350 feet high), each leg is jacked down to the sea floor until they support the weight of the entire unit lifting it out of the water. When all safety checks are complete, and the unit is found secured, the unit will switch to drilling mode and begin drilling the well. (featured video)
Submersible Drilling Rig This drilling platform combines some of the properties of drilling barges and jack ups. Only in this case, the production facilities are elevated on stilts hundreds of feet above pontoon like barges. After reaching the drill site. The crew floods the barges with water. The barges sink until they rest on the sea or lake floor, while the platform remains elevated above the water on stilts. Like jack-up, this platform is limited to shallow waters.
Semi-Submersibles drilling rig This unit is called as semi-submersible because once this unit is over the proposed well drilling location, they flood their huge ballast tank with the sea water and partially submerge below surface of the water. Semi-submersible will work for 300-2000 ft ocean depth. Semi-submersible has the advantage of being very stable in rough environments, but limited by the amount of equipment and supplies they are able to store on board.
more with Semi-SubmersiblesThere are 2 ways on how semi-submersible able maintain its positionover a proposed well, using the anchors and the dynamic positioningsystem (DP system).
Anchor methodAnchor method is considered as a traditional method of keeping a semi-submersible on location. Up to 12 anchors are run out away from the unitand set on ocean floor. The tension in the anchor chain or cable isincreased by using a large winch.
Dynamic Positioning SystemWith a DP system, the semi-submersible uses position information fromGPS system and radio beacons on the ocean floor to constantly monitorits position. If the DP computer detects that the oil rig is drifting offlocation (either caused by the wind, waves, or current), huge thrustersunderneath the rig will apply thrust to push it back over the well.
Drill ship Over the last 15 years, drills hips have been built to meet the growing demand for highly capable ultra- deepwater drilling rigs. Today’s generation of deepwater drill ships use the DP system for maintaining its position. Drill ship is capable of working for extended periods without the need for constant resupplying (larger storage capacity than semi-submersible). Other benefit of drill ship is their speed and maneuverability, drill ship can secure their operation and sail out of harms way like hurricane.
About Offshore EngineersOffshore oil and gas engineers play a critical role in all facets of offshore operations.Their skills are used in designing and constructing platform and subsea structures,drilling equipment, well head operations, subsea pipelines, production andtransportation operations.Offshore engineers can branch out into many specialties including: drilling andcompletions, robotics, marine corrosion, consulting and project management, pipelines,process control and systems, intervention and tooling, quality control and inspection,flow assurance, and subsea processes.Chemical engineering degrees are typically required in process engineers or corrosionengineers.
The working conditionsOffshore oil and gas engineers work in both onshore and offshore locations. Whileonshore, they perform their work in an office setting. Trips by helicopter to offshoreplatforms and or vessels can occur frequently, so be prepared by it. Accommodationand meals are provided, workers maybe exposed to inclement weather and potentiallyhazardous conditions; however safety protocols are strictly adhered to in order to avoidany risk. Periods of stay out at sea will vary depending on the project assignment.
Some criteria needed in becoming an offshore engineerIt takes a very unique person set to be able to survive and thrive in the offshore world,this are some criteria mentioned in careersinoilandgas.com• Good at math, sciences, and technology• Consider yourself at a great team-player, able to easily build personal and professional relationships.• Have the stamina and enthusiasm to work on ships, platforms, and other unique offshore work environments.• Can handle traveling for long periods.• Comfortable working 24/7 in a relatively isolated environment, with harsh weather conditions.• Think a career as an offshore engineer is exciting.
SKC : OFFSHORE OPERATION part 2ARIF FAJAR UTOMOL2C008118 Semarang, April 20th 2012