With reference to the subtitle of my colleague M. J P Imbert and my own paper, namely "A comparison between experiences in Brazil and Norway", I am afraid that my knowledge of the Brazilian operations is rather limited My paper is consequently limited to the situation in Norway and I leave to the audience to make the actual comparison as suggested by the title.
Like the Brazilian Continental Shelf, Norway's Shelf is characterised by a waste area boardered mostly with international waters and with only a narrow band of shallow water close to the coast Norway, in addition, shares the shallow part of the North Sea in a Shelf common with Britain and the other North Sea countries.
Since exploration for oil and gas first started on the Norwegian Shelf in the mid sixties most of the activities and the findings to-date have been in this particular area, leaving the deeper and more remote areas for later. These fields are at depths from approx 70m in the South (Ekofisk) to the deepest installation to date, Gullfaks C, on the edge of the Norwegian Trench, in 220m of water However, dung the late seventies and early eighties significant findings have been made in excess of 300 m, many which will be developed over the next few years
The 300 m plus deep Norwegian Trench was until 1982 an unpregnetable hinderance that prevented piping of oil and gas to the Norwegian mainland, leading Norway to export oil and gas to Britain and Germany through the Ekofisk-Emden, Ekofisk-Teeside and Frigg-St Fergus pipeline Systems.
It was for many reasons desirable to be able to land these resources in Norway, and in the late seventies and early eighties several development projects were run by a number of oil companies concentrating on both pipe-laying and pipeline support and repair techniques.
Both problems were solved through a series of tests, including deep simulated dives and welding repair projects, later to be demonstrated from the vessels to be used for the actual work.
This work eventually lead to the installation of the Statpipe Pipeline System crossing the Norwegian Trench twice into 300 m of water.
Since then, another large diameter pipeline has been installed between the Oseberg Field and the Sture terminal, near Bergen, crossing the trench at a water depth of approx 360 m
Up until just recently, all of the field developments on the Norwegian Shelf have been carried out by traditional steel or concrete platforms However, with increasing depth, emphasis has been put on development of sub sea production systems With the increasing depth, Norway is certain to see alternative solutions to the traditional platform concept such as tension leg platforms of various types and anchor assisted DP positioned early production vessels, combined with sub sea producing wells We are still, however, likely to see more traditional solution used combined with sub sea production techniques, down to in excess of 300 m.