The sun is not yet setting on the Forties Field’s productive life. First expected to be decommissioned in the mid-’90s, then shifted back to 2012, the current plan envisages Forties producing for another 20 years. (Photos courtesy of Apache Corp.)

Forty years later, Queen Elizabeth II has become Britain’s longest-serving monarch, while the Forties Field has a different
owner and is firmly established as the U.K. North Sea’s longest-producing field, having achieved its official 40th anniversary.

The field is recognized globally as one of the world’s historically greatest offshore projects. The past four decades have seen the development undertake an astonishing evolutionary journey from first oil up to the present day unrivaled by any other project in the world and will continue for many years to come, thanks to Apache Corp.

When the original operator BP chose to develop this giant field, first confirmed as a discovery back in October 1970 after being drilled by the semisubmersible Sea Quest rig, no one involved would have dreamed that it could still be producing in 2015, with plans potentially to take it well into the 2030s. But that is the current plan envisaged by Apache, which injected this declining giant with a whole new lease on life after taking over the reins from BP in 2003.

Culture is key
The industry-leading success of Apache’s ownership and operatorship of the field since acquiring it from BP for $680 million is due to a whole gamut of reasons, including the company’s bold leaders; its North American industry experience, operational know-how, technological innovation, teamwork approach; and its relationships with key contractors. But virtually all those involved today recognize that the key ingredient throughout has been a “can do” culture.

According to Apache’s North Sea Projects Group Manager Mark Richardson, “Culture eats strategy for breakfast,” quoting the renowned American management consultant and author, Peter Drucker. In this case, Apache’s culture has eaten strategy for breakfast, lunch and possibly even dinner too.

Named after the sea area in which it lies, the story of the Forties Field itself is a well-known one to any oil industry professional. It essentially mirrors the birth and rapid growth of the U.K. North Sea itself and is as synonymous with the region as Shell’s Brent Field (which was found the year after the Forties Field). The discovery of the Forties Field in Block 21/10 via well 21/10-1—which hit a 119-m (390-ft) column of good-quality oil—in October 1970 came only five years after the country’s first-ever offshore discovery, also by BP, made at the West Sole gas field. It was also just 10 months after the U.K.’s first-ever oil find at Montrose, made by Amoco.

When it began flowing oil to Scotland’s Grangemouth refinery in 1975, it was just months after the first offshore oil in the U.K. Continental Shelf (UKCS) began flowing from the Hamilton Brothers’ Argyll and Duncan fields in June that year.

World class
When the queen pushed the button that November day and formally began the flow of liquids (the field actually began producing two months earlier) through the 209-km (130-mile) pipeline stretching from Cruden Bay to Grangemouth, the inauguration signaled the successful completion of the crucial startup of the U.K.’s first world-class offshore development.

Initially featuring four large fixed steel platforms (a fifth was added in 1985) sited 177 km (110 miles) east of Aberdeen, the development had a total capacity of more than 100 wells and a production system that could handle up to 600,000 bbl/d. Following startup, the field’s operational life saw exemplary industry standards set throughout its lifetime.

The field’s original oil-in-place was put at 4.6 Bbbl of good quality 37° API gravity oil-in-place, with that fi gure now put at more than 5 Bbbl. When Apache—entering the North Sea for the very first time with the Forties acquisition—took over the operatorship, it was under no illusion that it was taking on anything less than a real-life industry icon.

Crown jewels
The field’s revered status was proven by initial reaction to the sale when it was announced by BP on January 12, 2003, being likened by many industry observers as akin to selling off the crown jewels. But for both companies it made perfect sense.

BP wanted to strategically divest itself of certain mature assets that it considered economically marginal. This was at a time, of course, when the oil price was fl oating at about $12/bbl. The U.K. major wanted to concentrate on expanding its global upstream portfolio into new frontiers, a strategy that it implemented and achieved superbly under the bold leadership of Lord Browne—the former BP CEO who earlier in his career was an asset manager of the Forties Field.

In something of a premonition, the company stated at the time of the announcement that the Forties asset “may be worth more to others than to us,” adding, “We believe this is an excellent deal for BP and Apache. Among other things, it brings to the UKCS a powerful U.S. independent for which Forties will be a highly material asset and therefore more likely to attract necessary future investment.”

Perfect fit
They weren’t kidding. For Apache, seeking to establish itself outside its core asset base in the U.S., it was a perfect fit.

Ironically, however, it was not the Forties Field that Apache initially had come over to discuss. The company had first cast its eye over BP’s Montrose Field asset. After deciding that asset was not what it was looking for, Apache turned its attention to the Forties Field. Both sides quickly realized a deal could be done, and the initial agreement was in place in less than two weeks. Richardson recalled, “It was a very fast turnaround. I was actually on my honeymoon. I was on my way back and was sitting in Gatwick airport. I opened up the Daily Telegraph newspaper, and there was a picture of the Forties Charlie platform with the headline ‘Forties sold to Apache.’”

BP agreed in principle to sell its 97.14% stake in the fi eld (not including the Forties pipeline, which it still owns today), along with a package of other assets in the Gulf of Mexico, to Apache for $1.3 billion.

At the time, Forties was producing about 48,000 bbl/d, having reached a peak plateau between 1978 and 1981 of about 500,000 bbl/d, with that larger figure having been well above the early expectations for the reservoir. That peak figure at one point represented 25% of U.K. oil demand.

On the sale date an estimated total of 2.5 Bbbl of oil had been produced from the fi eld, and BP estimated there were only 144
MMbbl of recoverable oil reserves left to be extracted.

Rejuvenated
Under Apache’s stewardship since 2003, however, Forties’ productivity has been transformed by a pioneering approach to the use of seismic and the drilling of wells.

The company’s intense focus on identifying and acting quickly upon fresh opportunities to access new reserves and enhance recovery rates has resulted in Apache so far achieving total production of more than 235 MMbbl from the field, with 120 MMbbl coming from wells drilled into the Forties reservoir by Apache.

There also have been reserve additions of more than 20 MMbbl of oil from new satellite fields, and Apache believes there is the potential for another 100 MMbbl of oil to come. Every 1% increase in the field’s recovery rate equates to about an extra 50 MMbbl of reserves.

It has become one of the best known examples in the global offshore industry of how to extract true value from a mature brownfield oil project. After the field was acquired Apache impressively managed to pay off the cost of the whole acquisition in less than three years.

Investment of $4.6 billion
Today, more than 20 years beyond the end of its original estimated lifetime, the venerable but reinvigorated Forties Field is expected to be producing well beyond the end of the next decade. All of this comes from a mature asset originally expected to be running dry by the early 1990s and which was penciled in prior to the sale for decommissioning by 2012.

Apache has invested close to $4.6 billion so far in the Forties Field, in virtually every facet of its infrastructure and what lies beneath. Key to the company’s success has been intensive drilling activity, the carrying out of extensive facility upgrades and modifications, the installation in 2013 (38 years after it first came onstream) of a new platform linked to Forties Alpha, and a complete reevaluation of the reservoir through the use of modern seismic techniques. All delivered with an excellent safety record and a level of operational efficiency that is “best in class” for the U.K. North Sea.

The following pages detail the first part of the story of how one of the most pioneering projects from the golden era of giant North Sea fields has been transformed from a declining giant into a rejuvenated offshore powerhouse,
which remains to this day a flagship in the vanguard of the U.K.’s
latest generation of projects.

The giant steel jackets and topsides for the Forties Alpha and Bravo platforms were constructed by Laing Offshore at a disused ship repair yard at Graythorp near Hartlepool, England, while Forties Charlie and Delta were built by Highland Fabricators (HiFab) at Nigg Bay on the Cromarty Firth, Scotland. All four were installed and hooked up in 1974 and 1975. First oil flowed in September 1975.

As part of this special report, also read:

Reawakening the Slumbering Giant

and

Technological Innovation Key to Enhancing Forties Field Drilling

Editor’s note: Part 2 of the Forties Field story will appear in January’s E&P issue.