Sudan is sub-Saharan Africa's third largest oil producer, and with the referendum comes the crucial decision of how to divide its wealth.

If south Sudan breaks away, the north risks losing most of its foreign currency revenue - most of the known reserves lie in the south, which produces nearly 500,000 barrels of crude every day.

Al Jazeera's Andrew Simmons reports from Paloich, one of the oil-producing areas in south Sudan, whose people say the oil is threatening to be a curse rather than a blessing. Companies operating there are being accused of damaging the environment and failing to support the community.

Al Jazeera tried to contact the oil consortium Petrodar for its response to the allegations. But no comment has been released by the Chinese state-owned petroleum corporation CNPC, or its partners Petronas of Malaysia and Sudapet (owned by the north Sudanese government).