The relationship between extractive industries and economic development in Africa has long featured in analysis of the region's fortunes. The continent is home to more than half the world's reserves of cobalt and diamonds, and has a large proportion of global phosphate and gold.
Africa is also a major oil producer. The continent's top four exporters account for almost 9 percent of global reserves, producing more than 6m barrels per day; with Nigeria pumping out just over 2m bbl/d, followed by Angola with 1.7m bbl/d. Africa's oil exporters shipped a total of 40m barrels of crude oil to the US in November 2011 - more than Saudi Arabia. And in a nod to the continuing dominance of commodities in the continent's recent economic success, in 2010, 75 percent of all Africa-bound FDI was attracted by its 15 oil producing countries.
There is now growing evidence that these figures represent just a fraction of the continent's actual hydrocarbon reserves. "Africa is under-explored," says Ali Moshiri, president of Africa and Latin American exploration and production at Chevron. "The cretaceous region all the way from the north of Nigeria to North Africa is unexplored. Africa probably has more resources than any place you can imagine."
The true extent of the continent's mineral wealth is impossible to determine at present, but there is growing evidence that Africa's oil and gas production may be on the verge of dramatic growth. A swathe of new oil discoveries have already swelled the ranks of Africa's hydrocarbon producers, with Ghana commencing oil production in late 2010. Uganda is nearing its first output, while reserves are being explored from Guinea and Sierra Leone, to Mozambique and Tanzania for their commercial viability. Most recent discoveries have been made offshore, but there is speculation that large parts of the continent - stretching from Nigeria to Algeria, and Uganda to Somalia and Tanzania - may be home to large untapped reserves.
This is a trend that is wetting the appetite of international oil companies such as Chevron, which is keen to build on its already sizable business on the continent.
"Believe it or not, I am excited about every one of the countries in Africa," says Mr Moshiri, repeating the point for emphasis. "I really do mean it when I say we are looking at every country."
Chevron, which has operations in Nigeria, Angola, Chad and Sudan, already invests $5bn annually in its African business. Of this, $1bn goes to sustaining existing operations, with everything else dedicated to exploration. "It is one of our largest areas of investment," says Mr Moshiri. "We look at West African geology all the time, and at the moment most of the focus is offshore."
Opportunity notwithstanding, few sectors generate more controversy than extractive industries. Historical mismanagement of resources and corruption in major oil producers such as Nigeria have left the industry more associated with the region's economic woes than progress.
As more countries join the ranks of oil producers, there is mounting international and domestic pressure for tighter regulation and greater transparency to leverage the continent's vast mineral wealth for broad based economic growth.
Organisations such as the Extractive Industries Transparency Initiative are working with African governments to strengthen governance. At the same time, legislators in the US and European Union are tightening disclosure rules for listed companies operating in overseas markets.
But oil majors still find themselves on the receiving end of criticism that the continent's natural resources are doing little, if anything, to drive social inclusion and economic development. Oil exploration in Nigeria's Niger Delta, for instance - home to most of the country's vast reserves - has been synonymous with graft, economic inequality and pollution.
Mr Moshiri is reluctant to be drawn on the relationship between governments in the region and the oil and gas industry, pointing instead to Chevron's social investment work. "Our company is very focused on social responsibility and social investment," he says, citing initiatives in Liberia and the Niger Delta.
Yet there have been some disputes. In 2008, Chevron's Nigerian subsidiary was cleared in a US district court of charges that it had been complicit in human rights violations by security forces, in a lawsuit brought by citizens from the region. In January 2012 an Ecuadorian court upheld an $18bn damages award for allegations of pollution in the Amazon by Texaco, which was later bought by Chevron. Chevron maintains that the Ecuadorean judgment is fraudulent and is appealing.
On the question of legislative moves such as the Dodd-Frank Act in the US, Mr Moshiri says only that "we obey the law of the US and the host country, we disclose everything according to the policy. It is up to the host government to utilise that information the way they want."
Given the legacy of mismanagement and conflict linked to extractive industries in a number of African countries, it is perhaps not surprising that oil companies often find themselves the subject of anger by expectant populations that have seen few tangible benefits from revenue generated.
Mr Moshiri argues that the issue can be further complicated by what he describes as a misunderstanding of the financial dynamics of the industry. "When you announce an investment from a foreign company people believe that right away there is production, revenue, profit and everybody getting rich. That is not true.
"I wish we could deliver as fast as people want, but it takes time," he adds, saying that "out of every 10 wells drilled in the industry, only one is successful...deep water investment can cost much as $10bn and the cycle is 10 years. When you sign a lease with a country the public view is 'where is the money?'"
A perceived over-reliance on mineral exports and the much touted resource curse frequently feature in analysis of the continent's economic and social difficulties. While the profile of many African economies is shifting towards more consumer market-led growth - prompting renewed optimism about their long-term growth prospects - the importance of resources as a source of revenue to finance development, and by extension the controversy they attract, is unlikely to diminish.
"In our business, we have to go where the resources are," says Mr Moshiri, espousing a realpolitik appreciation for the difficult choices that come with the business of extractive industries. "We are not a manufacturing company that can say 'where is the best place to build a factory? Ok, let's build it in the Bahamas.'"