On November 9, 2012, Heritage announced the successful completion of the acquisition of a 45 per cent interest in Oil Mining Lease (OML) 30, with effect from November 1, 2012.
In August last year, the company announced its intention to sell part of a gas block and borrow money from Genel Energy Plc to raise $450 million, easing concerns about how it will fund oil field purchases in Nigeria.
The cash, the company said, would partly fund Heritage Oil's acquisition of a stake in Nigeria's OML 30 oil assets announced last month.
Heritage's entry into the Nigerian oil and gas sector, according to a report in the London-based Financial Times (FT), is an unlikely alliance: a polo-loving local businessman and an oil company founded by a former supplier of mercenaries, with ties to coup plotters trying to overthrow African governments.
But it could provide the prototype for a new wave of companies hoping to take on the majors that have long dominated the Nigerian oil industry.
At least that is what investors in Heritage Oil are being asked to believe following a sale of assets in the Kurdistan region of northern Iraq to help finance a push into Nigeria's troubled energy sector.
Heritage's ambitions to transform itself into a significant producer in Nigeria, alongside local partner Shoreline Power, is based on its $850 million purchase of a cache of oil blocks in the conflict-scarred Niger Delta from Royal Dutch Shell, Total of France and Eni of Italy, which was completed in November.
The deal brings together Tony Buckingham, the founder, chief executive and leading shareholder of Heritage with Nigerian businessman Kola Karim.
Karim's Shoreline Energy International conglomerate is partnering the FTSE 250 company to create an indigenous Nigerian company seeking to reverse the fortunes of Shell's neglected OML 30.
Buckingham's colourful history, which ranges from helping to supply mercenaries to fight insurgents as well his links to coup plotters trying to overthrow the government of oil-rich Equatorial Guinea, to creating fortunes for himself and investors through a range of oil and mining deals, is well known to London-based investors.
Less well known is western-educated Karim. His business interests have extended to co-ventures with companies such as Costain, the UK support services group, and Schlumberger, the US-based oil services company. Beyond his ambitions to build an indigenous group capable of becoming a significant upstream oil operator in Africa's biggest energy industry, Karim is also patron of the Lagos Polo Club.
His group's interests span construction, power generation, engineering and telecoms across sub-Saharan Africa. Shoreline is, however, less experienced in managing oil operations than some of the other Nigerian groups seeking to establish themselves as the government encourages indigenous participation in the industry.
Paul Atherton, chief financial officer at Heritage, said the new venture was expected to raise production from OML 30, located in the western delta near Warri, Delta State, from a current level of 35,000 barrels a day to 55,000 b/d in the short term by improving extraction techniques, FT reported.
But further investment could see the block, which will formally be operated by the state-controlled, crisis-prone Nigerian National Petroleum Corporation (NNPC), increase production to 150,000 b/d within three to four years, according to Atherton.
Previous attempts to reinvigorate production at OML 30, one of Nigeria's most prolific blocks, have faltered. Production, which began in 1963, has declined sharply from a peak rate of 280,000 barrels attained in 1973.
Shell, which has long been Nigeria's foremost foreign investor, is reorganising its interests in the country. The company has yielded handsome revenues there for decades, but it has also been implicated in environmental corruption scandals and became embroiled in the banditry that stalks the delta.
Shell sold stakes in three licences in the Niger Delta in 2010 to Seplat, which has since improved output at the fields. Shell went on to sell stakes in other licences to First Hydrocarbon Nigeria, an affiliate of London-listed Afren, and Neconde Energy, a local consortium.
Atherton argued that the security situation in the area is now stable, following an amnesty, which the government said brought more than 20,000 armed men from their bases in the Niger Delta's creeks.
Production from OML 30 between 2006 and 2009 was severely hit by a combination of funding and security issues. Heritage said it would prevent interruptions in production by improving relations with the community and giving it a share of profits in exchange for helping to reduce vandalism.
International oil companies "have so many licences, they don't have the capital and manpower to focus on all of their licences", said Atherton.
With oil theft still rife in the Niger Delta and a contentious overhaul of industry legislation in the offing, some western groups are gradually selling down their Nigerian interests - particularly vulnerable onshore fields - to local operators, who in turn are forming alliances with less familiar western players or Asian groups.
Three weeks ago ConocoPhillips, the US oil group, announced it was selling its Nigerian businesses for a total of $1.79 billion to Lagos-based, Toronto-quoted Oando, one of the most ambitious local integrated energy groups. Oando will take on onshore and offshore interests delivering 43,000 barrels of oil a day.
But the challenge facing the new wave of indigenous companies, some backed by western groups, is to prove that they can turn round the long-term decline in output in Nigeria, one of the world's largest oil producers.
Investors in Heritage will be hoping the polo-loving Karim and the swashbuckling Buckingham can succeed where others have failed.