The main reason why such jack-up drilling rigs came into existence was because the oil drilling procedure was often interrupted as a result of wind and water conditions. With the support of jack up platforms, it was ensured that a firm base was provided to the oil rig so that the procedure of oil drilling could carry on without any interruptions.
The 1st jack up rig was launched in the year 1954. The material used to create the jack up platform is made of steel so that there is no threat of erosion when the rigs are placed in the water.
Each Jack Up unit is made up of 3 main components: the Hull, the Legs and Footings, and the Equipment used on the Jack Up.
Hull
Much like the hull of a boat, a Jack Up unit’s hull is watertight, and houses or supports the equipment, systems, and personnel needed to carry out normal operations.
While the Jack Up is afloat, the hull also provides the buoyancy needed to stop the Jack Up from sinking. The parameters of the hull can vary depending on the different modes of operation of the unit.
As a rule, the bigger the length and depth of the hull, the more variable deck load and equipment the Jack Up unit will be able to carry.
Leg and Footing
A Jack Up’s legs and footings are made from steel, and serve to support the hull while the unit is elevated, and offer the necessary stability to resist lateral loads.
Footings are used to increase the soil bearing area, meaning that the Jack Up can be used in areas with lower soil strength than if there were a smaller bearing area.
Both legs and footings have multiple characteristics which affect the way that the unit reacts in both elevated and afloat modes, and it is therefore important to understand these characteristics.
Drilling Rig Equipment
Each Jack Up unit will require certain equipment in order to fulfil its purpose. This equipment will therefore have an effect on the hull size and the lightship weight of the overall rig. The equipment used on Jack Up rigs can be split up into 3 major classifications: Marine Equipment, Mission Equipment, and Elevating Equipment.
- The Marine Equipment is everything which isn’t directly related to the mission equipment. This Marine Equipment category therefore encompasses all of the equipment that one might expect to find on an ordinary sea-going vehicle, such as a diesel engine, oil piping, electrical equipment, lifeboats, radar and sonar, communications equipment, and so on.
- Mission Equipment covers things like cranes, mud pumps and piping, derricks, drilling control systems, gas detection equipment and alarms, and so on.
- Elevating Equipment covers everything which is involved in allowing the Jack Up to raise, lower, and lock-off its legs and hull.
