Advertisement

Oil firms set to adopt better technologies

Saturday October 18 2014
rig

An oil exploration rig at Lake Albert. Picture: PHOTO | FILE

Oil companies in Uganda intend to deploy new extraction technologies that could improve recoveries and earn the country $500 million more annually. The polymer injection horizontal vent technology enhances oil recovery while improving wells’ drilling efficiency, according to the oil firms.

“We can enhance the oil recovery by 25 per cent,” said Total E&P general manager Francois Rafin. “It is a very substantial increase. “We are proposing to our partners to inject polymers to better squeeze the oil from the reservoirs.” 

Combined with the current ratio of 31 per cent, Uganda’s recovery rates could cross the 50 per cent line. Going by initial estimates, Uganda could earn close to $2 billion annually.

Polymer injection uses water that is injected into the wells to raise the oil closer to the point of extraction, making possible recovery of oil that would have otherwise remained in the ground using conventional extraction methods.

Mr Rafin said that, besides the technology, recoverability of oil depends on the field depth, oil viscosity, reservoir quality, its consolidation, porosity and permeability. His remarks point towards convergence between the government and the oil companies over choice of extraction technology and associated costs.

According to data from the Petroleum Exploration and Production Department (PEPD, Uganda’s oil and gas volumes have almost doubled from 3.5 billion barrels to 6.5 billion.

Advertisement

However, recoverable volumes increased only marginally from 1.2 to 1.4 billion barrels, representing a recovery rate of 34 per cent, which, while above the global average of 17 per cent to 30 per cent, was still below the potential of the fields’ productivity. 

The improved ratios are the result of a better understanding of the nature of the petroleum reservoirs in Uganda following appraisal work that the oil companies have been conducting.

Total E&P, Tullow Oil Uganda and China National Offshore Oil Company CNOOC are the current licence holders in the country.
Last year, the government issued a production licence for King Fisher well, which has 635 million barrels of oil but only 196 million barrels, or 31 per cent, is recoverable using conventional methods.

It is believed that more oil could be recovered using polymer injection.

High recovery rate

“While starting with 31 per cent is not low by international standards, CNOOC has undertaken to employ enhanced oil recovery on this field and, depending on the results, it is possible that we could get more than 31 per cent,” said PEPD head Ernest Rubondo.

Mr Rubondo gave the global average recovery rate as about 30 per cent, although some oil fields in countries such as Norway and the United States have achieved figures as high as 60 per cent using the methods proposed for Uganda. The technology includes use of gas injection, steam flooding and injection, polymer flooding and microbial injection.

The companies also plan to do horizontal drilling, which increases the efficiency of the reservoir while protecting the environment because it reduces the number of drilling points.

The practice has been that wells are dug vertically into the earth. Horizontal drilling involves digging vertically and then, at a certain point, horizontally beneath the earth. This technology enables shopping for oil at every point accessed.

“Using this method, you can multiply the projections by five times,” said Mr Rafin.

However, going by the Production Sharing Agreements (PSA) that the government has signed with oil companies, using this technology is likely to increase their recoverable costs.

Advertisement