When I received an invitation to make the opening address at Subsea International 89, which I was delighted to accept, my first question was naturally 'what is the theme and title of the conference'. I was somewhat surprised when advised that the conference was entitled 'Second Generation Subsea Production Systems', as it is now 46 years since the first subsea completion was Installed in Lake Erie in 1943. A generation is 30 years or so and, therefore, the organizing committee is quite correct in the title chosen. However, I am more inclined to view the progress of subsea, which has been quite protracted, In its various phases.

To the best of my knowledge, the earliest subsea completions m the 1940s and early 1950s were nothing more than land type production trees Installed m very shallow water to tap those reserves that extended into shallow-water areas. It was not until the mid 1950s that R&D was initiated to develop remotely operated equipment and techniques for subsea completions.

It was, I believe, in 1960 that the first subsea completion in the open sea was installed, offshore Louisiana, that did not have total reliance on divers. This was followed by Shell's manipulator operated system, which did not require guidelines and was used in the Santa Barbara Channel in the earlylmid-1960s. This period was perhaps the first serious approach to subsea development. As I see it, the next serious phase was m the early 1970s when a number of more sophisticated R&D projects emerged, such as; (The Chart available in full paper) I do not propose to dwell in detail on these systems, suffice to say that they were perhaps somewhat ahead of their time in the sense of industry needs; all were rather sophisticated, and although all have seen some active service in a prototype form and provided useful experience, none has appeared to be the ultimate answer for subsequent standard application. In saying this, one has to acknowledge that these systems have provided invaluable information, and certainly in the case of Exxon's SPS system many of its component parts have been widely adopted. The SPS system was essentially the basis of Shell Expro's Central Cormorant UMC, which has been technically successful However, if one can generalize, all these systems tended to suffer from over-complication, which may well have led to today's preference for simplification.

Notwithstanding all these activities, it is also my belief that subsea was not taken as the serious ultimate solution in the early 1970s. One reason for this may well have been, and it is certainly true for the UKCS, that the discoveries of large fields-say in excess of 300 million barrels-was still a reasonable expectation involving enormous capital expenditure and the challenge of designing platforms in this environment was enough without the added risk of subsea.

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