Well intervention is the term given to the processes that maintain, repair or replace the parts of an operating oil well. It is a specialist field and offshore asset management companies are used to help source the plant and operators necessary for these specialist interventions. There are two categories of intervention, called 'light' and 'heavy'. Light interventions are carried out on 'live' oil wells and involve lowering tools or sensors into the well to check equipment or carry out minor repairs. Heavy interventions also called 'workovers' involve stopping production from the oil well and making major changes to the equipment.
It is a popular misconception that oil wells produce oil continuously and efficiently from when they are discovered to when the oil runs out. However, this is not the case. The moving parts can wear out and seals and tubes age and start to leak. Sensors that control productivity and safety can fail. To avoid these and similar problems, oil well operators rely on well intervention equipment operated by intervention specialists. Light interventions use different types of thick wires called slick lines, wirelines or coiled tubing to clear or flush out blockages caused by sand or other substances from the well, like using drain rods to clear blocked drains. By attaching tools to the wire that is put down the well, you can also adjust 'downhole' equipment such as valves and pumps. By attaching electronic sensors, you can gather information about the conditions underground such as pressure, temperature and flow rate, these can be used to maximise production from the well. To carry out a heavy oil well intervention, you have to shut everything down and remove the well head equipment, using 'kill weight mud' to temporarily close the well hole so that oil does not continue to spurt out of the open hole. With the well head removed, leaking or worn out parts can be repaired or replaced before it is re-installed. The equipment like jack up barge can also be changed to adapt it to better perform when conditions in the oil basin have changed. Finally, the well could be capped to seal it when production is no longer viable.
Interventions and other operations on oil wells are made even more difficult when the oil well is offshore and the equipment you need to work on is on the sea bed. To perform subsea well intervention, not only do you need specialist equipment, but you also need some kind of well intervention vessel to carry it to the well and deploy it down to reach the sea bed. Two types of vessel are used, specialist ships that can perform interventions by deploying equipment from the ship, and either mobile or fixed offshore drilling rigs that stand on the sea bed and can therefore deploy much heavier equipment. Traditionally, ships were used for light interventions and rigs for heavy interventions. The decision about whether to perform interventions is chiefly an economic one. The well operator must offset the cost of the well intervention operation against the potential increase in oil production. Interventions that need rigs are considerably more expensive than those that can be performed from ships, and may not justify their cost particularly in the context of late field life operations where there is less oil to be recovered. Costs can be reduced by using new or enhanced intervention methods. These enable operations that previously needed multiple heavy lines deployed from an expensive rig to be performed from one lighter line carried by a ship thus significantly reducing the overall cost. Attollo Offshore Ltd specialise in offshore asset management, embracing these new and innovative technologies in the offshore oil industry.
As leaders in offshore asset management, Attollo Offshore Ltd have unrivalled expertise in the challenges and demands of extending the economic viability of mature offshore oil basins. We embrace advancements and innovations in well intervention technology, working to substantially increase the productivity of offshore oil wells while significantly reducing the overall costs. We challenge existing conventions and work hard to make interventions that were previously prohibitively expensive, more economically viable, using suitable strategic marine assets. Visit http://www.attollo-offshore.com/ to see what we can offer you. You can also email us at email@example.com, or ring +44 1224 959810 to discuss your needs with us today.