SLOK Holding is the owner of SLOK Nigeria Ltd., the leading indigenous player in the upstream sector of Nigeria's oil and gas industry.

Midstream operations are sometimes classified within the upstream sector, but these operations compose a separate and discrete sector of the petroleum industry.

The newspaper covers the upstream sector of the global oil and gas industry with full-time staff correspondents in all the major centres of the industry.

Exploration and Production are deemed to fall within the upstream sector of the oil and gas industry.

The midstream operations are often taken to include some elements of the upstream and downstream sectors.

The upstream sector is narrow, with a characteristic transversal profile, in "V" shape.

It is devoted entirely to the 'upstream' sector of the industry - the exploitation of oil and gas - as opposed to the 'downstream' refining and retail sector.

ONGC is the leading player in India's upstream sector, accounting for roughly 75% of the country's oil output during 2006, as per Indian government estimates.

The crisis has revealed the importance of an integration policy both to integrate the upstream and downstream sectors and to provide effective public services at local level.

CEPCO has performed work for Saudi Aramco, the world's largest oil company, in the upstream sector and the midstream sector.