The Moskito is an electric, remotely operated hot tap tool. Using patented technology, three steps are combined in one machine:
- Securing machine to hull
- Drilling drain holes for inlet and outlet
- Fastening valve and hose connection
The entire process is operated and monitored from a surface laptop. ROV or divers are only used to position the tool on the wreck, open and close the valve and connect hoses if required. Moskito is secured to the hull using three powerful electromagnets. The tripod legs are controlled individually with high precision, allowing the operator to align the machine properly on curved or uneven surfaces. The light-weight umbilical is suitable up to medium water depth, without the need for any tether management system. For larger depths, the Moskito can be run directly via the ROV.
At the heart of the machine are the Drill Units. The operator controls rotational speed and feed speed during the drilling process. The special drill bit design latches onto the shell plating
immediately after penetrating it. When Moskito is released from the hull, the Drill Unit remains firmly in place. On top of the drill bit is a gate valve and an ROV-friendly hose connection. Once the hose is connected to the Drill Unit, the valve can be opened and the oil is pumped to the surface.
Heavy oils, large depths, low temperatures and high viscous fluids imposes extreme requirements on the pumping system. Miko’s heavy duty pumping spread is based on a positive displacement pump which is submerged onto the wreck close to the tapping location. The pump can lift fluids of any viscosity ranging from diesel to heavy fuel oil or crude oil.
The suction hose is equipped with coupling that is stabbed onto the Drill Unit. The automatic latching system along with the robust and simple release mechanism makes the connection and disconnection an easy task for both divers and ROV.
The pump is run by an electrical motor which is controlled through a frequency converter on the surface. The control panel gives direct feedback of the power consumption at any given moment. This enables the crew to maximise the pumping speed to the conditions at hand while the power consumption gives an indication to whether the pump is lifting seawater or oil. Thus the amount of water is kept to a minimum.
The oil is pumped into a tank which is selected for the task in question, such as ISO tanks on deck or the surface vessel’s internal tanks. At very large depths, submerged tanks may be considered.