In a New Orleans court in 2013, a letter was read out from BP, the British oil giant. Tensions had been bristling for a while in what would soon become one of the toughest stand-offs with the US government in corporate history, but this was a real show of defiance from the FTSE 100 company.

“BP did not agree to pay what is already hundreds of millions of dollars, and potentially billions, to claimants with ‘losses’ that do not exist in reality,” the letter said.

It was three years after the Deepwater Horizon tragedy but it would still be another three before BP would finally turn the page on its darkest chapter. The blowout of the Macondo well in 2010 cost 11 men their lives and spewed four million barrels of oil into the Gulf of Mexico. The financial penalties cut far deeper than BP imagined, and the company is likely to wear the scars for years.

BP first estimated the bill would be $7.8bn (£5.9bn) – which itself would have spelt one the biggest settlements of its kind. By the time of its 2013 Louisiana stand it had become clear that the rising deluge of claims – many legitimate, but increasingly opportunistic – had dashed any hope of keeping the spiralling costs to the low billions. BP spent $14.3bn responding to the catastrophic oil spill and a further $8.6bn on environmental costs before agreeing to pay compensation to businesses and local authorities across Alabama, Florida, Louisiana, Mississippi and Texas.

At the end of 2015, the bill for claims and litigation had hit $22bn, almost as much as BP spent on the clean-up itself. The “absurd” claims which BP objected to included a $21m payout to a Louisiana rice mill 40 miles from the coast which, in the year of the disaster, earned more revenue than in any of the three years prior to the spill.

Two hundred miles from the Gulf, a construction company in northern Alabama called for compensation to the tune of $9.7m, despite conducting no business in the region and enjoying one of its best years on record in 2010. “Simply put, BP undervalued the settlement and underestimated the number of people and businesses that qualify under the objective formulas that BP agreed to,” came the court’s response.

Last week, almost one year to the day since the US government approved an $18.7bn settlement for BP’s role in the Deepwater Horizon spill, the oil major has finally drawn a line under the disaster which almost brought it to its knees.

“People are starting to say, ‘We can see the future again’,” says Bob Dudley. Only now is BP preparing to move out of the shadow cast by one of the biggest corporate settlements in US history to focus its sights firmly on growth. “We’ve had to keep our heads down for so long, but drawing a line under Macondo has changed the mood. We’re feeling a lot more positive about the future,” Dudley adds.

Brian Gilvary, BP’s chief financial officer, told investors this month the company had “made significant progress” in resolving outstanding claims, and could now estimate “all the material liabilities remaining from the incident”.

The move “provides our investors with certainty going forward”, he said.

Certainty is in short supply in the oil industry as the ongoing oil price rout creeps towards the two-year mark. The latest round of financial reports from the majors bears testament to the pain inflicted on companies by the historic market collapse.

BP’s results for the second quarter failed to meet market expectations as sluggish oil prices and lower production volumes took their toll. Profits came to $720m, falling short of the $840m in underlying profit that analysts expected. Although the earnings were higher than the $532m in the first quarter, they fall well below the $1.3bn profit BP generated in the second quarter of 2015 when oil prices were higher.

It was a similar tale of woe across the industry last week. Shell reported a 93pc drop in profit, while France’s Total, Spain’s Repsol, and Statoil also unveiled grim results. For BP the challenge is to convince investors it has done what it takes to weather the oil price storm and is poised for growth. Ahead of its results the sector’s top analysts returned from a field trip to BP’s Baku oil project in Azerbaijan seemingly convinced about the company’s improved prospects.

Lydia Rainforth, a Barclays analyst, says BP is heading towards “a sweet spot” where momentum in growth and efficiency will meet declining costs. “The changes being made should not be underestimated with the company set to cover capital expenditure and dividends from organic cash flow at $50 to $55 a barrel in 2017,” she adds.

It’s hard to argue with the data: BP’s share price has rallied almost 30pc since April, outpacing the oil and gas sector by 10pc. Its shares trade at around 450p a share, up from around 400p one month ago, and Barclays predicts that the price is poised to return to a pre-Macondo levels of 600p within 18 months.

“The last time BP’s share price traded above 600p was over six years ago – in April 2010, just before the Macondo accident. Much has changed for BP over the past six years and the portfolio is simpler and operations more efficient across both the upstream and downstream businesses,” she adds.

Jefferies’ Jason Gammel, a veteran analyst of the company, agrees. He says BP’s upstream business has “by necessity” become a much leaner, more focused organisation post-Macondo. “We believe that BP is re-emerging as a competitive super-major. The company has set forth an agenda to grow production profitably from projects with cash margins that are 35pc higher than the current corporate average,” he adds.

BP expects to build its production capacity by 500,000 barrels a day (b/d) by the end of 2017 and reach 800,000 b/d by the end of 2020.

“We believe the targets for installed capacity are very credible based on the major capital projects BP currently has in construction,” Gammel adds.

With visibility to 2020, the company now has an eye on the post-2020

time frame. Gammel points to BP’s most recent investment decision, to expand its existing Tangguh gas production project in Indonesia, as evidence of the more carefully honed strategy. “The [Tangguh] project has a key feature that we expect from many other potential new projects for BP: it is near existing fields and will benefit from installed infrastructure,” Gammel explains, adding that further expansion of BP’s projects in Oman Khazzan and Egypt are also likely to be high value investments.

BP believes that by playing to its strengths it will avoid the need to take on the kind of costly acquisition that rival Shell pursued with its £36bn takeover of BG Group this year.

“Some say BP doesn’t have growth capacity and that we need a large acquisition. That is not our view,” Bernard Looney, chief of BP’s upstream arm, told analysts in Baku.

BP is eager to stress that its conservative approach is not without imagination. It may be focusing on existing fields and locations, but to drive the aggressive cost cutting needed to survive a new low oil price world order the major has turned to Silicon Valley to drive a modernisation of its North Sea activities.

“We want to embrace innovation and modernise the way we do business, adopting digitisation and the use of big data which we believe can drive a real step change in performance and efficiency,” Looney says.

For Biraj Borkhataria, an analyst with RBC Capital, the case for BP is less certain. To reduce its debt while sustaining its dividend and delivering growth, BP will need costs to fall as oil prices rise. Oil service companies have already stripped out costs and would be hard pressed to deliver further savings to oil producers. At the same time the tentative recovery in global oil swung into reverse last week to hit three-month lows, raising questions over the longer term future of the oil market recovery. Another risk factor for BP’s long-term success is its heavy involvement with Russia as the country’s relations with Western powers continue to deteriorate. The legacy hanging over BP from the Macondo costs is also not quite over, Borkhataria warns.

“Overall, we estimate a $5.8bn charge for 2016, with a $2.4bn charge for 2017, numbers we believe are higher than many had been expecting,” he says of the continued Macondo charges.

“One of our key points of reservation around BP is the addition of fixed cash payments relating to the Macondo settlement in its financial framework. BP stated its free cash flow break-even could be reduced to $50 to $55 a barrel in 2017. However, this also excludes any payments related to Macondo, which we see as material,” he adds.

BP is focusing firmly on the future but the past is not yet as far away as it would like.