News EBI Adds Project 51: Microbially Enhanced Hydrocarbon Recovery

A combined effort of all three academic partners in the Energy Biosciences Institute will seek to increase the amount of oil that can be extracted from existing wells by using environmentally friendly microbes within their geological habitat to help recover residual oil and enhance production.  They will also research methods of in situ biorefining to improve oil field life cycle costs and reduce environmental impacts.

The process is called “Microbially Enhanced Hydrocarbon Recovery,” and the program to investigate it is the 51st research effort in the EBI to be funded by BP, the global energy company. More than two-dozen scientists from the University of California at Berkeley, Lawrence Berkeley National Laboratory, and the University of Illinois at Urbana-Champaign will participate in the investigations.

Terry Hazen, principal investigator and senior scientist in earth sciences at Berkeley Lab, said the program is designed to understand all biological, environmental and geological aspects of oil resources, including microbial community structure, function, and distribution, linked to the physical and chemical nature of the sedimentary rock reservoir in which they are housed. “From this basic information,” he added, “we hope to develop predictive models of MEHR applicability in various environments, as well as novel technologies to enhance hydrocarbon recovery for fuels.”

Eventually, Hazen said the use of microbes might even result in “oil sweetening,” or converting its chemical structure to a more environmentally friendly and useful form, like methane.

He and his co-principal investigators will direct teams in different aspects of the process. Hazen will focus on ecogenomics, UC Berkeley professor of microbiology John Coates will research flow rates and mechanisms, University of Illinois associate professor of geology and microbiology Bruce Fouke will study reservoir geology and geochemistry, and Berkeley Lab earth scientist Susan Hubbard will head the monitoring and modeling team.

It is estimated that less than 20 percent of the oil reserves in a typical subsurface reservoir is extracted using primary recovery techniques. An effective MEHR program could recover another 5 to 10 percent or more. The microbes used in this bio-recovery process produce harmless by-products such as slippery low-viscosity substances or gases, which in turn help mobilize the oil and facilitate oil flow and extraction.

Microorganisms grow as biofilms lining the surfaces of sedimentary rock grains, as well as “bacterioplankton” floating in the fluids that fill the rock pore space. These microbial communities can enhance oil recovery in a variety of ways, which include breaking down the molecular structure of crude oil and making it more fluid, producing carbon dioxide gas or biomass that displace the oil, and by creating biosurfactants that behave like slippery detergents in moving the oil.

As MEHR reduces or eliminates the need to use harsh chemicals during oil drilling, it is an environmentally compatible method of carrying out tertiary oil recovery.

Among the program’s “natural subsurface laboratories” will be a demonstration injection well and two monitoring wells in Decatur, IL, which are being drilled as part of a research program on carbon sequestration being funded by the U.S. Department of Energy and the Midwest Geological Sequestration Consortium (MGSC) headed by the Illinois State Geological Survey (ISGS). EBI researchers will study the genetic makeup of microbial communities found in the formation water and rock samples extracted from the wells, and then quantitatively link their metabolic activity and distribution to the environmental and geological conditions of the subsurface.

Fouke said the goals include “developing quantitative models that identify these underground biology networks, predicting reservoir porosity and permeability changes that occur during resource extraction, and establishing universal approaches to using MEHR to recover oil.”

The Decatur injection well and monitoring wells are located at Archer Daniels Midland in Decatur, whose ethanol plant will provide the carbon dioxide for the carbon storage and capture tests. Injection of CO2 is scheduled to begin next October. The wells will descend more than 6,500 feet, where the gas will be trapped between sandstone and shale in a natural saline reservoir.

The EBI teams will analyze the environmental and geological conditions of shallower Paleozoic hydrocarbon reservoirs in addition to the deeper Cambrian CO2 sequestration saline reservoir target. This includes water and rock geochemistry and hydrocarbon composition and will chart the geologic thermal burial history of each sample. Then they will determine the genetic spread and profiles of the subsurface microbes, including bacterial and viral communities, under various physical and chemical conditions. Their results will be gathered into a model framework that future EBI research can use for MEHR microbial engineering, on-site biology manipulation, and treatment and monitoring strategies.

“We hope to develop conceptual models of microbial community structure and function that may enable control of these environments toward maximizing energy recovery, energy quality, and carbon sequestration, as well as understanding the fundamental mechanisms of petroleum maturation and migration,” Hazen said.

According to BP officials, the prize in enhancing recovery rates is enormous. A 1 percent improvement in recovery on BP’s original hydrocarbons equates to 2 billion barrels of additional reserves. Worldwide, a 5 percent increase in recovery – a conservative increase thought to be achievable – would yield an additional 300-600 billion barrels, which could be critical to meeting the growing global energy demand.


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