Biogenic fuel gas generation in geologic hydrocarbon deposits
A method for stimulating methane production from a carbonaceous material is described. The methods may include the step of contacting the material with cells of a methanogenic consortium under anaerobic conditions to form a reaction mixture. The method may also include maintaining anaerobic conditions for a time sufficient to permit methanogenesis, and collecting methane from anaerobic water or head space of the reaction mixture.
1. A method for stimulating methane production from a carbonaceous material comprising the steps of
a) contacting the material with cells of a methanogenic consortium under anaerobic conditions, forming a reaction mixture,
b) maintaining anaerobic conditions for a time sufficient to permit methanogenesis, and
c) collecting methane from anaerobic water or head space of the reaction mixture,
wherein the consortium is a concentrate of microorganisms prepared by the method of:
i) extracting anaerobic formation water containing said microorganisms from an underground carbonaceous formation,
ii) providing liquid transport means for transporting said water while maintaining an anaerobic state,
iii) providing collection means for collecting said microorganisms in an anaerobic state from said water,
iv) transporting said water through said collection means whereby said microorganisms are collected from said water, and
v) removing said microorganisms in a concentrated form in said water from the collection means, whereby a concentrate of said microorganisms is prepared.
2. The method of claim 1 wherein the carbonaceous material is present in situ in an underground formation.
3. The method of claim 1 wherein the carbonaceous material is extracted from an underground formation.
4. The method of claim 1 wherein the methanogenic consortium is essentially sediment-free.
5. The method of claim 1 wherein the concentrate has at least ten times more microorganisms per unit volume formation water than the formation water of step (a).
6. The method of claim 1 wherein the anaerobic formation water is obtained from a methane-producing formation.
7. A method of preparing a concentrate of microorganisms comprising a consortium of methanogenic microorganisms, comprising the steps of,
a) extracting anaerobic formation water containing said microorganisms from an underground carbonaceous formation,
b) providing liquid transport means for transporting said water while maintaining an anaerobic state,
c) providing collection means for collecting said microorganisms in an anaerobic state from said water,
d) transporting said water through said collection means, whereby said micro-organisms are collected from said water, and
e) removing said microorganisms in a concentrated form in said water from the collection means, whereby a concentrate of said microorganisms is prepared.
8. The method of claim 7 wherein the collection means comprises tangential filtration.
9. The method of claim 7 wherein the collection means comprises centrifugation.
10. The method of claim 7 wherein the concentrate has at least ten times more microorganisms per unit volume than formation water of step (a).
11. The method of claim 7 wherein the concentration contains at least 108 cells/ml.