LEMIGAS develops microbe to enhance oil recovery

By Johannes Simbolon

JAKARTA (JP): The state-owned Research and Development for Oil and Gas Technology (LEMIGAS) has been developing technology using microbes to enhance oil recovery in the country's oil fields.

The agency recently reached a milestone in its venture by completing a five-year laboratory research which proves the use of microbes to enhance oil recovery.

Head of LEMIGAS' research and development office, Evita Legowo, said recently the laboratory study indicated that the use of microbes could enhance recovery factors in oil fields by between 50 percent and 100 percent.

"But, we have yet to stage some field tests to justify the conclusion," Evita said.

She added that the agency has plans to carry out some field tests at the state oil and gas company Pertamina's oil field in Prabumulih, South Sumatra, in the near future. Unocal Indonesia Ltd, a subsidiary of the U.S. giant energy company Unocal Corp, has also shown interest in "participating" in the field test.

The laboratory research for the Microbial Enhance Oil Recovery (MEOR) technology began in August 1993 with two grants, US$450,000 and Rp 950 million ($86,000), from Pertamina.

Pertamina's exploration and production director, Priyambodo Mulyosudirjo, said the agency's achievement was expected to give an alternative for the government to increase the country's oil production amid the current scarcity of new oil discoveries.

"We really appreciate the agency's achievement," Priyambodo said.

International consultant Wood McKenzie predicted in 1995 that the country would turn from being a net oil exporter to net oil importer by 2008 due to a dwindling reservoir of existing oil fields and the scarcity of oil discoveries over the past decade.

Currently, the country produces 1.5 million barrels per day (bpd) of crude oil but consumes about 700,000 bpd. According to McKenzie, the country's oil output will drop to 1.2 million bpd in 2008, less than the then national consumption.

Some analysts predict Indonesia will remain a net oil exporter longer than McKenzie has predicted but all agree that Indonesia will not be able to rely on its oil resource for long.

EOR

Evita said oil companies can only recover between 15 percent and 20 percent of oil reserves if they only rely on the pressure inside oil wells to push oil to the surface.

They can increase the oil recovery rate to between 20 percent and 35 percent by injecting hot water into the wells to add pressure to push the oil to the surface. This is called secondary enhanced oil recovery (EOR) technology.

But, a large percentage of oil reserves still cannot be bought to the surface due to several factors, including the fact that they are too viscous or trapped in the reservoir rock.

Evita said experts have developed an advanced EOR technology to lower oil viscosity and loosen the attachment of oil to rock. This tertiary EOR technology could increase the oil recovery rate to between 35 percent and 50 percent.

Tertiary EOR technology is carried out by injecting steam or chemicals into wells or using microbes.

Evita said that at present, the most popular technique of all tertiary EOR technologies is the one using steam injection, while the one using chemical injection is considered too expensive and environmentally unfriendly.

The country's largest oil producer, Caltex Pacific Indonesia, which is jointly owned by the United States oil companies Chevron and Texaco, has been using the steam injection technique at its Duri oil field in Riau.

Evita noted, however, that the MEOR has been growing more popular today since it is considered cheaper and environmentally more friendly.

Under the MEOR system, Evita said, oil companies use microbes to produce bioproducts, including biosurfactants, biopolymer, bioacid and biosolvents which chemically reduce oil viscosity and release oil from the reservoir rocks, and, as such, facilitate the flow of oil to the surface.

Evita said LEMIGAS once imported microbes that were used by oil companies in the United States for its research but the microbes could not survive on the type of nutrition consumed by local microbes.

"Each microbe can apparently only survive in its own environment. The U.S. microbes might be more familiar with cheese so that they quickly died when we give them tempeh," Evita joked.

After failing to develop research on imported microbes, LEMIGAS turned its focus on microbes which were discovered in local oil fields.

"We found that some microbes exist and grow well in oil wells at a certain temperature and depth. We then thought how to make the microbes proliferate and industriously produce the bioproducts which are needed to release oil from the reservoir rock," Evita said.

Evita said LEMIGAS has managed to develop a type of nutrition which can boost the proliferation of microbes and increase the production of their bioproducts. She would not reveal the nutrition.

"Pertamina and LEMIGAS hold the patent of the formula of the nutrition," Priyambodo said.

Priyambodo said Pertamina had yet to calculate the investment needed for an oil company to install MEOR technology.

The government has given some incentives for contractors to develop oil resources in marginal, frontier and tertiary EOR fields because oil discoveries have been rarely made in the conventional areas over the past decade.

The incentives include, among others, that the government takes 75 percent of oil output from the development of tertiary EOR, marginal and deepwater areas, leaving the remainder to contractors. In conventional areas, the government take 85 percent of oil output.