April 28, 2005
Methane Producing Bacteria Found In Oil Fields

Luca Technologies reports on the presence of bacteria in an oilfield which are producing methane from the oil.

DENVER, CO (April 28, 2005): Luca Technologies LLC today announced that its researchers have confirmed the presence of a resident, methane-generating community of microorganisms ("microbial consortium") in substrate samples taken from the 110,000 acre Monument Butte oilfield located in North Eastern Utah. This site represents the latest in a series of active "GeobioreactorsTM" that Luca Technologies has identified since its first demonstration of this phenomenon in the Powder River Basin coalfields of Wyoming. Geobioreactors are sites where microbial conversion of underground hydrocarbon deposits (oil, oil shales, and coal) to methane is ongoing. Such Geobioreactors may offer the potential of turning currently finite energy reserves into methane "farms" capable of long-term, sustainable energy generation.

"The hydrocarbon resources available in the Monument Butte oilfield are very large, making the possibility of shifting from oil production to the ongoing farming of clean, natural gas an attractive consideration," said Robert Pfeiffer, president and chief executive officer of Luca Technologies. He noted that the Monument Butte site was one of six oil fields across the United States that Luca has been studying. The company has demonstrated two of those sites to be robust, methane-generating Geobioreactors, and two to be less actively generating methane. Three additional sites are not currently active but may have the potential to be turned into active Geobioreactors through cross-inoculation with microbial consortia from active sites.

Luca scientists have also begun to isolate and identify particular members of the Monument Butte microbial consortium. Through partial DNA sequence analysis, the company has identified Clostridia and Thermatoga as two of the key members of this consortium. Clostridia form a broad genus of bacteria known for their diverse metabolic pathways. Clostridia frequently thrive in anaerobic environments and many species are known for their heat tolerance. Thermatoga microorganisms are known to play a role in the anaerobic oxidation of hydrocarbons to alcohols, organic acids and carbon dioxide. Thermatoga also thrive in high temperature environments, such as those found in sub-surface oil wells.

"Oil within the Monument Butte field has a waxy composition that may facilitate the strong real-time methane generation we see at this site," commented Mr. Pfeiffer. "If so, then areas with large accumulations of waxy oil – for example, the Daqing Field in Northeast China -- could prove to be important sites for the bioconversion of residual oil to methane and the restoration of these 'spent' sites to economic energy production."

Note that oxygen suppresses the methane generation.

Luca scientists, employing the tools of modern biotechnology and genomics, have now shown that living methane generating, microbial consortia are present and actively forming methane within some of these hydrocarbon substrates. In addition to demonstrating that methane formation by these microbes can be stimulated by the introduction of nutrients or suppressed by heat sterilization or the introduction of oxygen, Luca has shown that radio-labeled CO2 (carbon dioxide) introduced to these substrate samples is converted to radio-labeled methane. This demonstrates that the methane formation is the result of a biological process occurring today.

Luca has a more detailed paper on their web site about this report. (PDF format)

Because their environment is hostile to familiar forms of surface life, oil reservoirs were originally thought to be devoid of life. However, more recent research has revealed that many oil reserves contain a variety of active and diverse microorganisms (19). In general, these microorganisms have been studied in the context of fouling, souring, and degradation of oil 8 reservoirs. Various gases are frequently associated with oil wells, and Luca’s data indicate that methanogenesis, the creation of methane, is another biological process occurring in some oil reservoirs. In addition to identifying these active systems (Geobioreactors), it will be important to understand the variables that control this overall methanogenic process.

Because oil is a liquid, it is likely to be an easier substrate for the microbial consortia to contact, biodegrade, and convert to methane compared to solid-phase substrates such as coal and the kerogen in shale. Biodegradation is carried out by the consortia, and it has been shown that a mixed group of microorganisms is more effective at biodegrading organic compounds than any of the component strains acting alone (5). These microorganisms utilize the hydrocarbons as both a carbon and energy source, and the process most likely takes place at the oil/water interface (13). The enzymatic diversity within these microorganisms required to carry out the myriad of metabolic steps involved in methanogenesis is extensive. The ability to influence and control these microbial reactions in situ has major economic implications.

Back in November 2004 Luca Technologies claimed to have found methane generating bacteria in the coal deposits of Wyoming's Powder River Basin. At the time of that previous report another blogger asked me if I thought this report could lead to a practical way to extract large amounts of methane from coal. My initial reaction was that injection of bacteria into coal beds would be very problematic because the bacteria would not diffuse rapidly through solid masses. The amount of drilling needed to get good diffusion of the bacteria might result in costs too hgh to make such an approach economically feasible. Well, in their latest report they specifically note that getting bacteria into contact with liquid oil is easier than getting it into contact with solid coal.

Of course coal is much more plentiful than oil. But old and heavily depleted oil fields which have a lot of inaccessible oil left which injected bacteria might reach. If bacteria injected could reach those oil left-overs then bacterial injection might become an economically viable way to extract otherwise unreachable energy.

The November 2004 report is also online and Luca points out that if even a small percentage of a coal field's coal could be converted to natural gas in situ then the amount of natural gas that could be produced would be substantial.

The primary goals of the research were to evaluate the recent and ongoing biogenic methane formation in PRB coal seams and to identify some of the variables that may affect the creation of biogenic gas in these coals. The sheer size of the PRB coal-bed resource as substrate for biogenic methane creation is the primary incentive. The coalbeds of the PRB are thought to contain ~580 billion tons of coal in contiguous seams at least 20 feet thick (DeBruin et. al, 2001). Only a small portion of this coal is accessible for domestic use via mining. Although substantial quantities of methane exist in the PRB coal seams (estimated total resource of ~37 TCF, DeBruin et. al, 2001), this quantity of gas likely represents a small fraction of the methane that could be created through biogenesis supported by hydrocarbon substrates within the coals. For instance, the conversion of only 1% of the known PRB coal resource above would generate approximately 86 TCF of gas (Luca estimation).

So how much as 86 trillion cubic feet of natural gas worth? Natural gas is priced in dollars per thousand cubic feet with a general upward trend in natural gas prices now putting natural gas at the wellhead at about $5 per thousand cubic feet. If we assume $5 per thousand cubic feet then conversion of 1% of the Powder River Basin coal into natural gas yields a market value of about $430 billion. Bacteria suddenly become fascinating little creatures.

Here are some numbers (first 3 items for the US and the last 3 for the world) on natural gas production and reserves to put those 86 TCF of potentially extractable gas in perspective.

As of December 31, 2002, the estimated U.S. total proved reserves of natural gas were at 183.46 trillion cubic feet (tcf).

...

Natural gas consumption reached 22.6 trillion cubic feet (tcf) in 2000, a four percent increase over the previous year.

Natural gas supply, consumption, and imports are projected to steadily expand, with consumption projected at 35 tcf in 2025.

...

Current worldwide natural gas resources are about 13,000 tcf and natural gas reserves are about 5,000 tcf.

Global estimates place the gas volume resident in oceanic natural gas deposits in the range of 30,000 to 49,100,000 tcf, and in continental natural gas hydrate deposits in the range of 5,000 to 12,000,000 tcf.

World production of natural gas is dominated by the United States (24 tcf) and Russia (21 tcf), whose combined gross production accounts for 45 percent of the 102 tcf produced in 1998.

Aside: While some more recent estimates of oceanic clathrate gas deposits put the numbers way lower if we could ever get at the clathrates economically then CO2 emissions could rise so high we really would melt the polar ice caps.

At a 1% conversion efficiency then Luca's process might be able to extract an amount of natural gas from a coal field that equals 47% of current US natural gas reserves. A practical proposition? Imagine drilling down vertically to a coal seam and then drilling horizontally into the coal seam many times at places spaced apart so that all coal would be in reach of water and bactera sent down into the drill holes. Could this be done cost effectively? Or would the distance between drill holes have to be only a few inches due to lack of ability of the bacteria to migrate very far away from the drill holes? Also, if the holes couldn't be kept full of water oxygen exposure might stop the anaerobic process of methane production in the bacteria. So pumping of pure nitrogen gas into the holes might be necessary as a way to keep the oxygen out.

Any readers know enough about coal drilling costs and about water diffusion in coal to take a stab at guessing about the economic viability of such an undertaking? Also, assuming a 1% conversion efficiency due to diffusion problems what volume amount of coal would contain 100 times the energy of 1 trillion cubic feet of natural gas? My guess is one would be better off drilling more thoroughly into a smaller area in order to get a conversion efficiency much higher than 1%. But maybe that would require something akin to converting the coal to powder to even make that work Such an effort to turn coal into powder underground might be too costly. Just guessing though.

Share |      Randall Parker, 2005 April 28 08:39 PM  Energy Fossil Fuels


Comments
back40 said at April 28, 2005 11:00 PM:

For existing coal bed methane (CBM) extraction hydraulic sand fracture is used. The bed is fractured by water pressure and sand grains flow into the fractures. When the pressure is released the sand grains (or plastic beads) hold the fracture open so that methane can escape. It seems that a variant of this practice could be used to inject water and methanogens.

In existing CBM water is what keeps the methane from escaping coal pores. Coal is like a methane sponge and holds quite a lot of methane so long as the pores are blocked by water. Yield increases over time after water is pumped out, growing larger for a couple of decades. Perhaps played out CBM fields would be good candidates for inoculation with methanogens and water to rejuvenate the field.

There are also tricks using CO2 injection. It seems that when CO2 is injected it displaces methane. Methane is desorbed due to preferential sorption of CO2. It may be a way to sequester CO2 while producing methane. CO2 would also help keep an anaerobic environment, and some is used in the complex multi-stage process of methane production by some methanogens.

Rob McMillin said at April 29, 2005 11:39 AM:

Am I wrong or would this be a potentially interesting approach for getting more energy out of depleted oil fields?

Randall Parker said at April 29, 2005 11:44 AM:

Rob,

If you are wrong then I'm wrong right along with you. ;>

Robert Bradbury said at May 1, 2005 9:31 AM:

The problem is complex but I suspect it will be a
field where people will make a lot of money. One
problem will be the need to inject water as a hydrogen
source. There seem to be some of the bacteria that are
relatively salt tolerant, so this wouldn't be a problem
in places like Texas where one could use water pumped
from the oceans. In places like Wyoming or Alberta it
is going to be a bit more difficult (expensive) however.

It would also appear that this approach can be used for
CO2 sequestration. Apparently some species of bacteria
will convert the CO2 to CH4 as well. The CO2 will tend
to displace the CH4 and O2 (derived from extracting the
required H2 from H2O) because they are lighter gases. It
would appear that there would be a big incentive to build
methane powered gas plants near sources of the otherwise
uneconomic coal (or oil fields) and pump the CO2 produced
by the plant back into the coal/oil bed.

What I would like to know is precisely *where* the energy
is coming from to perform the reduction of H2O and CO2?
I.e., how efficient are the bacteria in performing
these chemical reactions? It almost leads one to speculate
that perhaps the bacteria may be leveraging the heat produced
either from the core of the planet or the gravity produced
pressure of the overlying rock. I.e. we either have
indirectly powered nuclear or gravity based power
sources.

[And *yes* Randall, I'm aware there are carriage
returns in my comment. That is because *your* blog
software doesn't properly wrap form entry lines in Netscape
4.xx. It also requires Javascript be enabled which is a
potential security risk. I'll stop using CR's when *you*
adopt some software that has completely sufficient for
blogging features, but is compatible with legacy browsers
that are smaller, faster and ultimately more secure for
WWW browsing (via security through obscurity).
If you send me a private email as to the source for
the blog software you are using I'll be happy to rake
them over the coals personally. Its a classic example
of people using overly fancy engineering and forgetting
about concepts such as security and usability.]

Thomas B. Woods said at May 1, 2005 6:07 PM:

Anerobic decomposition of barn yard manure will also produce methane. Are the bacteria the same in both processes?

Heading Out said at May 2, 2005 6:49 AM:

There is a technique now commercial in Australia for long horizontal hole drilling in coal that may be useful. It uses high pressure waterjets for the drilling and is currently being used for methane extractioin before they go in to longwall mne the coal. The holes are quite large since the instrumentation and drive mechanisms take some space, but the turning radius of the drill is less than a foot, to go from vertical to horizontal. There is a modified form being developed in the US for oilwell drillling, though some of the tools that have been "fielded" in this area use a lot more "smoke and mirrors" than others.

Till said at September 15, 2005 2:53 PM:

hi there,do you guys see application of such bacteria above ground? well, co2 is abailable, anaerobic conditions can be created. assuming this, what other things are needed for the methane production...they niet nutrients (P,N), do they also nee e.g. biomass (instead of oil) as carbon source or is co2 then the carbon source instead?
Best regards
Till

Pat Moore said at November 4, 2005 3:03 AM:

Does anybody know of bacteria that can turn biomass to oil?

K.J.Chauhan said at November 8, 2005 2:54 AM:

I am keenly following the developments in this frontier technolgy area. The idea itself has generated lot of hopes in the oil indusry world over. Many researchers are eager to accept the challenge of developing the technology that promises energy security of this planet for many generations to come.
I,however, have few doubts.Firstly generation of methane from oil/coal by microbes from comparatively simpler substrates such as carohydrates have taken millions of years. Therefore, would it be possible for injected microbes to create such massive effects in short span of time?Secondly, Archea, the major known methanogens are difficult to grow even in laboratry & making them grow vigerously in not so conducive environment of subsurface geobioreactors will be agigantic task.

Dhruvi said at April 20, 2006 12:50 PM:

y r the gas prices going high?

Shrikant Dhoot said at June 14, 2007 10:06 PM:

The diffusion of bacteria will definately depends upon the coal porosity. Drilling the holes and injecting bacteria with nutrients will certainly increase the rate but not viable. Also once the bacteria are injected they will start consumption and as the process goes on it will be a more Methane environment so the stability of bacteria is again a point to be addressed. The process starts by liguifaction and then liquids converted to gas. So i think this technique is applicable in abandoned mines and not reachable coal.

intricatenick said at August 20, 2009 2:02 PM:

It can be done - the way it actually works is to stimulate the dormant bacteria that ALREADY live in the coal to grow. The energy is provided by the chemical bonds that are already present in the coal. As the coal degrades into smaller and smaller components energy is released to each part of the chain in the microbial consortia. The reason this doesn't happen is mainly due to nutrient depletion. This nutrient depletion leads to the loss of enzymatic co-factors that are needed for the microbes to release the potential energy bound up in the coal. The end result of this process is methane.

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