The complete rig is made up of some 20 modules for ease of transport and assembly. As each module typically weighs under 35t, they can be lifted into position using the platform’s own crane. Modular construction also allows the rig to be put ashore between jobs, or easily moved from platform to platform.
Development of a prototype modular workover rig is well advanced and is receiving extremely good feedback from oil companies and service operators that need such equipment.
Well intervention
Most types of well intervention, both light and heavy, can be carried out using this modular workover rig. These include the various wirelining procedures, running coiled tubing or jointed pipe, and also drilling to extend existing wells into hydrocarbon layers in the field that have not yet been drained.
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The work over rig concept is made up of a number of modularised sub assemblies for ease of transport and straight forward assembly in remote locations.
LER Container
The LER container transforms the platform’s hi-voltage electrical power supply, down to the work-over rig’s electric voltage, at 690 Volts. The control system for the rig is also located inside this container, together with all the local motor starters for all equipment.
Circulation Skid
The circulation skid is lifted as a single unit and positioned inside the balcony. The skid includes two trip tanks with 2 pumps, standpipe manifold, kill & choke manifold and a waste tank used for well control by measuring and controlling the well fluids.
It is positioned inside the balcony, between the platform T-deck and the rig’s sub structure and is remotely operated from the control cabin. The Circulation Skid and the rig system are used for liquid well control and circulation during well cleanup operations.
Cherry Pickers on BOP Deck and Drill Floor
In the BOP room there is a need for access to the various areas where equipment and hoses are connected. The cherry picker provides the rig crew with safe and quick access.
Drill floor cherry picker ensures access for maintenance and routine checks in derrick and drill floor area. They can also be used as cranes as they are equipped with winches that can handle loads up to 1,5 tonnes.
Main & Auxiliary Hydraulic Power Units (HPU)
The main and auxiliary HPUs are located at the west platform wing deck. The main HPU comprises four hydraulic pumps which supply the hoisting system and top drive unit with hydraulic power. The auxiliary HPU has two hydraulic pumps that supply all other hydraulic equipment on the rig. Electrical power is supplied from the LER container.
Sub-Structure with Skidding System
The sub-structure elevates the rig floor to the same elevation as the platform pipe deck. This enables the platform pipe deck to be used for storing well tubular and pipe handling equipment.
The skidding system is positioned on top of the sub-structure, making it possible to skid the drill floor in both X- and Y-axes. This is needed in order to move the rig well centre vertically on top of the platform well heads.
Pipe Handling System
This is positioned on the platform T-deck and consists of a pipe handling crane, pipe gripper head, pipe racks, tubular conveyor and a pipe rack skidding system.
The structure within the pipe handling system also forms the base for the drillers cabin. The system can be skidded east/west in order to centralise the pipe feeder towards the well centre at the drill floor.
Derrick
The derrick is constructed from two triangular truss columns and is a key part of the hoisting system. The hoisting system is rack & pinion drive, where the racks are mounted on a guide rail on each column. Each column has its own drive unit with pinions and motors. The top drive is mounted on a dolly that is fixed to flexible joints on each drive unit.
Control Cabin
The control cabin is located on top of the structure for the pipe handling system, on the platform T-deck. From the two identical operating chairs inside the cabin, the driller and the assistant driller can remotely operate all equipment on the rig.
Typically, the driller operates the hoisting system, hydraulic slips, the circulation skid and the top drive, while the assistant driller operates other pipe handling equipment like iron roughneck, pipe crane and catwalk. The fire & gas system, BOP and choke panel for the rig is also monitored from the control cabin.
Drive Units and Top Drive
There are two hydraulic drive units on the rack & pinion system for lifting and lowering of the top drive assembly. Load from the work string being pulled or run in the well is transferred to the rack & pinion system by use of the top drive.
The relatively small but powerful top drive is used to rotate the drilling string. The elevator at the bottom is used when lifting the different types of tubular in and out of the well.
The main benefits of this compact unit are its lightweight and transportability. It has been designed to be cost effective to manufacture and be easily fitted and removed from existing platforms of various designs and complexity. This reduces the amount of work required to prepare the platform for further production or final plugging.
Well plugging
When wells reach the end of their productive life they must be plugged, which means they must be abandoned with a ‘rock to rock’ barrier. The Rolls-Royce rig handles all phases of this operation, a cutter to cut the pipe below the seabed and ability to install the cement plugs and recover production pipe, christmas tree and other equipment to the platform.
This means nothing is left of the well above the seabed and reinstatement is completed with minimuml disruption to the seabed in accordance with the regulatory requirements.
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We continue to strengthen our service network, both in the number of service engineers and dedicated workshops equipped to service our products around the world.
Product operation and service training programmes are provided to deliver the right level of knowledge transferred to customer organisations to ensure our products can be operated safely and efficiently.
Should technical issues arise, our experienced 24/7 support team is only a call away. Call +31 20 700 6474 or your details.
We offer tailored service agreements and training programmes:
- Equipment service and maintenance packages
- Operator and maintenance training
- Spare parts
- Upgrading
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