With favorable economics and production growth at the forefront of operators’ minds, an EOR method with microbes at its core is gaining attention in the oil patch.

Bio-EOR is being called a practical solution for extending the life of waterfloods in today’s economic environment. Speaking during EnerCom’s Oil and Gas Conference in Denver on Aug. 16, Transworld Technologies CEO Karl Weber explained how using the right microbes with the right geochemistry can lead to production gains and prolonged field life. Key to the process is getting to know the native microbes that live at the oil-water interface.

Using molecular biology with samples collected from a well site, the company studies the microbes—deciphering who they are, what they’re doing and how they can facilitate oil flow. The details are used to form the building blocks of what Weber described as the “microbial carbon disassembly plant,” nature’s process for breaking down large carbon molecules. For Transworld Technologies, the final product is methane.

“This disassembly process and the byproducts that are created by it is where the opportunity comes for the bio-EOR recovery mechanism,” Weber said, later adding that the microbes live in the water. “It’s really the water that creates the environment for bio-EOR to produce more oil.”

During a waterflood, Transworld’s Activ8 formula—used in mature oil fields—is injected at low concentrations into the reservoir to stimulate the microbes. Once injected, it essentially helps the microbes become more efficient at the disassembly process, he explained. First, the methane dissolves into the water and then into the oil, ultimately creating methane microbubbles. ReActiv8 is used for biogenic gas fields.

“Those bubbles serve an important purpose,” Weber said. They change the interfacial tension between oil and water, helping divert the water into other pore spaces and freeing up space for trapped oil to move.

Results from a 2015 real-world application of the process showed a 28% production increase over the daily baseline. During the project, which is still ongoing, it took about five months to see the first response to the treatment. The treatment process lasted about 12 months, he said, calling the process easy and straightforward.

But it all depends on upfront sampling. Not all reservoirs are suited for this type of EOR technology. Weber said the company, which charges based on its performance with fees customized to each field’s economics and commodity price adjustments, can determine whether a project will qualify for the treatment within about six weeks.

“We are looking for a rigged game, a stacked deck—the combination of the right microbes, geochemistry, field characteristics and an operator who really grasps the potential of bio-EOR,” Weber said. “That combination for us creates a win-win proposition for both the operator and also Transworld.”

Weber admits that bio-EOR can’t deliver the same recoveries as other EOR methods involving the use of polymers, alkaline surfactant polymers or carbon dioxide.

However, “we can deliver our recoveries at far less costs than those other alternatives,” he said, noting there is no capex requirement for the technology. Operators don’t have to pay upfront and the technology doesn’t require field, operations or equipment modifications. “It’s clearly the least expensive EOR that’s out there.”

The estimated cost per incremental barrel of production for bio-EOR is $9, compared to about $21 for EOR using polymers, $36 for ASP and $55 for CO2, according to Weber.

Velda Addison can be reached at vaddison@hartenergy.com.

Comments