All oil and gas wells inevitably shifts from asset to liability, whether the result of reaching its economic limit or sustaining irreparable damage. At the end of its life cycle, a subsea well and its supporting infrastructure must be carefully dismantled to
ensure they pose no safety or environmental threats and to salvage useable components. In addition to creating significant safety and environmental hazards, failure to properly abandon a subsea well can lead to a noncompliant status with regulatory
agencies and undermine an operator's image. Despite its multiple liabilities, abandonment offers no real return on investment, underscoring the importance of minimizing cost. The challenge is to retrieve the wellhead without damage so it can be used again, minimizing or eliminating damage not only to the wellhead but also to personnel and environment.
This paper will describe the technological tool system available to retrieve subsea wellheads in a single trip. This technology serves as an alternative to equipment that poses environmental and safety hazards, such as mobile offshore drilling units and explosive severance devices. By latching on to the external profile there is no damage to the internal seals. Also the external latch procedure allows more clearance to allow the cuttings to flow out of the ports and away from the working mechanism. The wellheads retrieved have a much greater chance of being re-used with minimal damage. The external latch design allow for more strength and less chance of tool failure. This paper will also discuss some global case histories.