This is the story of Forties oil field which is generally known as the field where offshore production of oil was started throughout North Sea. At that time, every technological and engineering step was a fist, as biggest field in North Sea set to break the boundaries in attempt to start production. Sir Ian Wood, the former CEO of Wood Group, describes it as a science fiction sort of engineering development at that time.
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On 7 October 1970, BP the operator and owner of Forties field officially announced that it had found oil that was commercially viable, about 180 km (110 miles) north east of Aberdeen. The discovery was made by Sea Quest, an offshore semisubmersible drilling rig of BP. Sea Quest drilled four more appraisal wells in order to establish magnitude of Forties reservoir.
Construction and Installation
BP launched a construction program for next 5 years that was one of biggest in the history of UK. This program broke all boundaries and created the blue print for the future development in entire North Sea.
The construction included the marvelous engineering and the fabrication of platform topsides and steel jackets, subsea Forties Pipeline System which enabled the pumping of the produce to shore located 170 km (105 miles) away from the rig, and a terminal of crude oil at the Grangemouth refinery.
There was not only the need of building equipment for drilling and producing oil offshore, but there was also the need to build an entire infrastructure portfolio, that would make sure that oil is discovered, produced, refined and reaches the consumers at the fuel stations of BP itself.
The oil was first produced and then pumped down Forties Pipeline System to the shore in the month of September in 1975. Forties project was inaugurated by Her Majesty Queen Elizabeth II on 3 November 1975. A button was was pushed by the Queen to start the production officially. The production rate was 10,000 barrel/day. Next year saw more wells being brought into the production across four Forties field. Soon there were 130 wells in operation. The production reached its peak at 500,000 barrel/day.
1980s Billions of Barrels
In May 1982, Forties field hit the milestone of a billion barrels of oil production.Throughout 1980s, more investment was made. Fifth platform known as Forties Echo was added to Forties oil field in the year 1986. Late 1980s saw the commissioning of Artificial Gas Lift system, a pioneering system at that time.
Forties Artificial Lift project (FALP) used the produced gas by pumping it back down in the well to aid flow of the oil going upwards. Work commended in the year 1989. The first gas was introduced to Forties Alpha platform and Forties Delta platform in the year 1991.Forties reached the second milestone of production in May 1989 when it had produced 2 billion barrels oil.
1990s Falling Production
It was predicted by the engineers and the geologists of BP at end of discovery that Forties field will have an expected life in to early 1990s.By the 1990s Forties platform and the infrastructure were reaching an age of 20 years, end of the designed life. Subsea Forties Pipeline System was already corroding, so by the year 1991, a decision of installing new, larger pipeline of 32 inches was made by BP. This new pipeline would have a cost of $1.5 billion (£1 billion).
Initially this new pipeline to the shore enabled the increase of production from 630,000 barrel/day to about 900,000 barrel/day. As 90s continued, the production from field started declining rapidly. The production fell to 75,000 barrel/day in the year 1997 and then to 66,000 barrel/day in the year 1999. It was being expected in the industry that BP would now start winding up operations of Forties, with final shutdown around the year 2000.
2000s BP Sells to Apache
By the year 2003, the production from the Forties had gone down to about 45,000 barrel/day. It was about 855,000 barrel lower than what it used to be about 10 years before. BP decided to sell entire Forties Field and the infrastructure to Apache Corporation which was based in US. The decision was made in January 2003.
At that time, there was a lot of political and public backlash because of the deal. The sale of Forties was seen as BP selling its crown jewel, and UK loosing ownership of one of the biggest fields. But BP did not sale Forties Pipeline System and kept its ownership, ensuring that BP was paid for transporting the oil that was produced in the field.
Other oil fields in North Sea were also utilizing the pipeline. According to estimates, today the pipeline transports about 30 percent of all the UK North Sea oil to the shore. It was estimated by BP when it made the sale, that Forties field which had produced more than 2.4 billion barrel oil, had about 144 million barrel oil left.
Apache immediately undertook full seismic reevaluation of Forties field. And it was found that the field had 800 million barrel oil which was not previously accounted for. New campaign of drilling was launched by Apache. Twelve new wells were drilled in the year 2004 and the production increased from 40,950 barrel to 61,680 barrels.
Foggy Forties Keeps Marching On
Apache has done investment of about $4.6 billion (£3 billion) in Forties field after taking over from BP. The work carried out include seismic modeling of Forties reservoir, installing new platforms, drilling of new wells, FASP, right next to Forties Alpha which has given the Forties field better power capabilities along with capacity of about 25,000 barrel. Today the production is around 60,000 barrel/day.
In the year 2012, oil was produced for the first time from Bucchus field. It is another oil field which ties back to the Forties utilizing the infrastructure of Forties field, and heightening the importance of Forties in North Sea.Because of success of this operation, new Aviat oil field is going to be tied back to Forties in coming months. Due to work and investment by Apache it is expected that Forties field will continue producing oil at a rate that is commercially viable for another 20 years. Increasing the total lifespan of Forties field about 60 years, ending in 2030s, that is another 40 years to its original expected life.