AED drilled a number of wells that seemed to indicate Puffin...

AED drilled a number of wells that seemed to indicate Puffin field held a high volume of untapped reserves, estimated to be 100 million bbl, albeit in a complex geological setting.

The company embarked on an ambitious floating production, storage, and offloading development (using the Front Puffin FPSO) and had planned to reach a production level of 30,000 b/d and potentially bring in a second FPSO to develop the southern part of the field as well as tie in the nearby smaller Talbot oil field that AED had acquired in 2007. However the group only managed to produce a total of 2.2 million bbl because the development quickly succumbed to water inflow from the reservoir that swamped the oil flow.

The field was effectively abandoned in 2009. AED was then caught up in legal problems with FPSO operator Sea Productions and ordered to pay millions of dollars in damages. The company went into administration and Sinopec was left on its own.

Sinopec maintained the subsea equipment under a care and maintenance scheme for 6 years. In 2014 the Stena Clyde semisubmersible rig permanently plugged and abandoned the seven Puffin production wells and removed any connections to the hydrocarbon reservoirs.

I do remember that when Sinopec acquired 60% of the Puffin field from AED the oil price was around USD150 per barrel. We all know what the Oil price did after that record high.
Sinopec must still be twitching at that investment decision.