摘要 |
The invention provides a method and apparatus for performing a plug and abandonment operation on a subsea well. A wellhead interface module is located on a wellhead, which accommodates a volume of wellbore fluid in fluid communication with the wellbore. A system control module receives a signal from a sensor in the chamber and is configured to derive volume data relating to a change in volume of wellbore fluid in the chamber and compares the derived volume data with a volume change expected due to the removal of tubing from the wellbore. In embodiments of the invention, this enables a change in wellbore conditions to be characterized, for example a fluid influx or a fluid loss, from the volume data. The method may comprise providing wellbore fluid to the apparatus to replace fluid which enters the wellbore to occupy the volume vacated by the tubing, and/or removing or adding fluid in fluid influx/loss situations respectively. |