From Bulletin 1997, N.3
 
 

THE START OF AGIP'S OIL EXPLORATION IN DEEP WATERS

Introduction

One of the most interesting innovations to take place in offshore hydrocarbon exploration and production over the last few years has been the shift towards areas with increasing water depths. As a result of the increased activity, it now can be difficult to find equipment for drilling in deep waters. AGIP was one of the first European companies to set its sights on offshore activities. It drilled the first offshore well in Western Europe, at Gela in 1959 and was highly successful in offshore ventures in Iran, Egypt, the North Sea and in the Congo.

The foundation of Seagap

In the early seventies, AGIP took the initiative of creating an international consortium, of just four companies, to develop a technology for deep water drilling. Thus Seagap was founded, a consortium grouping together AGIP, Phillips, Getty and Hispanoil (which had replaced Conoco). In 1972, the Offshore Drilling Company of Houston was commissioned to build the drilling ship "Discoverer Seven Seas", which had to drill down to a 1,500 meter water depth, a totally revolutionary target for that time. The rig was to be based on a dynamic positioning system, i.e. it did not have to be anchored to the seabed.

Before this time, 262 drilling rigs were operating in the world: of these, 236 had a drilling potential limited to a 200 meter water depth, 25 to a 370 meter water depth, one to a 450 meter depth and the Sedco 445 rig which could drill down to a 700 meter water depth. The construction of the Discoverer Seven Seas would double this potential, enabling drilling in a 1,500 meter water depth.

In order to supervise the rig’s construction at a Japanese shipyard, and subsequent drilling operations, the Discoverer Seven Seas Joint Team was set up. The team comprised 12 people, three from each company. In the AGIP group there was Mr. Emilio Cerrito (currently Senior Vice President of AGIP), Mr. Renzo Cesaroni (currently Drilling Manager at Saipem) and Mr. Leonardo Nanni (now retired). During its five years of activities, Mr. Bruno Bonomo (currently the Libya Gas project manager) and Mr. Giovanni Rivis (now retired) joined the team.

Operations with the Discoverer Seven Seas

The Discoverer Seven Seas left the shipyards in 1975 to drill its first test well offshore the Ivory Coast, in a water depth of just over 100 meters. All equipment had to be tested, but above all, the procedures, which had so far been theoretically based, needed to be fine-tuned. Many problems cropped up and had to be solved in a matter of a few minutes. Re-drilling the same borehole, after the rig had moved away because of some difficulties due to the sea conditions, proved to be extremely hard. The use of a small submarine, on board the rig, turned out to be invaluable.

After the Ivory Coast, the Discoverer Seven Seas drilled in water depths of more than 1,000 meters offshore the Congo, Egypt, Guinea Bissau, Colombia, Spain, Italy, Labrador, and once again offshore Spain and Italy. In 1977 it broke the world record in the Congo, drilling the Sanga 1 well in a water depth of 1,341 meters. The Discoverer Seven Seas then improved on this record by a few hundred feet, while drilling in Spain, offshore Ibiza.

Having reached its goal of perfecting a technology which could drill in water depths of over 1,000 meters, the work of the Seagap consortium came to an end. Twenty years on from that meaningful experience, the great deal of knowledge acquired remains. This knowledge has enabled Agip to lead the way in this sector, by putting the Aquila reservoir into production, which is located in the Channel of Otranto, at the mouth of the Adriatic. As a result Agip holds the European record for drilling in the greatest water depth: 850 meters.