IN SITU METHANOGENESIS MODELING AND RISK ANALYSIS

• US 20110308790A1
• Filed: 06/16/2011
• Published: 12/22/2011
• Est. Priority Date: 06/16/2010
• Status: Active Grant

• Current Assignee: Conocophillips Company (ConocoPhillips)
• Original Assignee: Conocophillips Company (ConocoPhillips)
• Inventors: Strapoc, Dariusz, Lee, Jaedong, Pittenger, Michelle Ann, Lambo, Adewale J., Huizinga, Bradley James, Turich, Courtney Hanna
• Granted Patent: US 10,221,432 B2
• Time in Patent Office: Days
• US Class Current: 166/250.01
• CPC Class Codes: C09K 8/582 characterised by the use of bacteria
• CPC Class Codes: C12N 1/20 Bacteria; Culture media therefor
• CPC Class Codes: C12P 5/023 Methane
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/295 Gasification of minerals, e.g. for producing mixtures of combustible gases E21B43/243 takes precedence
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

This invention generally relates to natural gas and methylotrophic energy generation, bio-generated fuels and microbiology. In alternative embodiments, the invention provides nutrient amendments and microbial compositions that are both specifically optimized to stimulate methanogenesis, or “methylotrophic” conversion. Additionally, the invention provides methods to develop nutrient amendments and microbial compositions that are both specifically optimized to stimulate methanogenesis in a given reservoir. The invention also provides methods for the evaluation of potentially damaging biomass formation and scale precipitation resulting from the addition of nutrient amendments. In another embodiment, the invention provides methods for simulating biogas in sub-surface conditions using a computational model.

Claims

1. A process for geochemical modeling of biogas generation from sub-surface organic matter-rich formations comprising:

a) characterization of organic carbon-rich substrates, one or more microbial organisms, and inorganic mineralogy in a subterranean formation;

b) determination of a injectate-water chemistry to promote biogas generation in the subterranean formation;

c) geochemical modeling of injectate-water properties in the subterranean formation;

d) geochemical modeling of generated biogas within the subterranean formation;

e) optimization of the injectate-water chemistry to promote biogas generation;

f) optionally repeat c, d, and e;

g) injection of a injectate-water with optimized injectate-water chemistry into a subterranean formation; and

h) monitoring of biogas production and changes in produced-water chemistry.

2. The process of claim 1, wherein said geochemical modeling comprises:

a) developing a geocellular facies model,

b) determining facies parameters from existing sub-surface data, geological models or both sub-surface data and geological models,

c) distributing facies properties throughout the geocellular facies model,

d) modeling initial biogas production to match historical field production, and

e) simulating future biogenic gas production with optimized injectate-water chemistry and flow through the subterranean formation.

3. The process of claim 1, wherein said geochemical modeling of the injectate-water models fluid transport of the water-soluble amendments, microbial growth, or both water-soluble amendments and microbial growth within the subterranean formation.

4. The process of claim 1, wherein said organic carbon-rich substrates (a) are identified within the subterranean formation as organic-containing zones targeted for enhanced biogas production.

5. The process of claim 1, wherein said injectate-water chemistry (b) is optimized using a matrix experiment with model bioreactors containing organic-rich rock substrates by varying the concentration of one or more compositions of the injectate-water chemistry including pH, salinity, nutrient concentrations, sodium, potassium, magnesium, sodium chloride, potassium chloride, ammonia, phosphate, sulfate, chloride, trace elements, iron, manganese, tungsten, tungstate, cobalt, zinc, copper, boron, borate, molybdenum, molybdate, selenium, nickel, vitamins, sodium-nitrilotriacetate, p-aminobenzoate, biotin, cobalamins, cyanocobalamin, methylcobalamin, hydroxycobalamin, folic acid, lipoic acid, nicotinic acid, pyridoxine, thiamine, riboflavin, pantothenic acid, amino acids, dietary minerals, fatty acids, carotenoids, tocopherols, riboflavins, phylloquinones, niacins, citric acid, ascorbic acid, cholecalciferol, and combinations thereof.

6. The process of claim 1 wherein said geochemical modeling of injectate-water models interaction of injectate-water with indigenous subterranean formation water, spread of injectate-water through the subterranean formation, spread of microorganisms through the subterranean formation, interaction of microorganisms with the subterranean formation, and combinations thereof.

7. The process of claim 1, wherein said geochemical modeling identifies one or more injection strategies for injectate-water selected from the group consisting of continuous injection, periodic injection, and supplemental injection, wherein injection allows bleed-in of a concentrated nutrient mixture with the injectate water at optimized concentrations.

8. The process of claim 1, wherein one or more producing wells are monitored before, during, or after injectate-water including monitoring one or more parameters selected from the group consisting of gas-production rate changes, well-pressure changes, one or more microbial organisms, tracking water tracers, tracking stable-isotope tracers, or combinations thereof.

9. The process of claim 1, wherein said optimized water chemistry is slightly alkaline between about pH 7.1, pH 7.2, pH 7.3, pH 7.4, pH 7.5, pH 7.6, pH 7.7, pH 7.8, pH 7.9, pH 8.0, pH 8.1, pH 8.2, pH 8.3, pH 8.4, and pH 8.5, moderately saline between about 2, 3, 4, 5, and 6 g/l total dilute saline, between about 1, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, and 3 mmolar magnesium, between about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and 14 mmolar phosphate, between about 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, and 26 mmolar ammonium, and a mixture of mineral nutrients, trace metals and vitamins.

10. The process of claim 1, wherein said enhanced biogas generation is promoted through a methylotrophic biogas pathway in combination with carbon-dioxide reduction, acetate fermentation, or both carbon-dioxide reduction and acetate fermentation.

11. A process for reducing risk during biogas generation from sub-surface organic matter-rich formations comprising:

a) characterization of organic carbon-rich substrates, one or more microbial organisms, and inorganic mineralogy in a subterranean formation;

b) determination of a injectate-water chemistry to promotes biogas generation in the subterranean formation;

c) identifying one or more risks associated with the proposed injectate-water process;

d) analyzing the risks associated with the proposed injectate-water process;

e) testing the risks associated with the proposed injectate-water process;

f) optimization the injectate-water process to reduce or avoid risks during biogas generation;

g) optionally repeat c, d, e, and f;

h) injection of a injectate-water with optimized injectate-water chemistry into a subterranean formation; and

i) monitoring biogas production and changes in produced-water chemistry.

12. The process of claim 11, wherein said risk analysis (c) comprises:

a) listing potential problems

b) evaluating the probability and severity of the potential problems,

c) identify the causes of the potential problems,

d) propose preventative actions and plan contingencies,

e) design a test for one or more potential problems,

f) test problem and one or more preventative actions, and

g) identify a preventative action to prevent or minimize the associated risk.

13. The process of claim 11, wherein said risk is selected from the group consisting of oxygen contamination, biomass plugging, formation of hydrogen sulfide, sludge development, biofilm formation, adverse effects from nutrient impurities, corrosion, scaling in the formation, scaling in the wellbore, inorganic precipitation in storage tank, inorganic precipitation in the mixing tank, inorganic precipitation in the wellbore, inorganic precipitation in reservoir formation, sludge in the storage tank, sludge in the mixing tank, biofilm formation in the storage tank, biofilm formation in the mixing tank, biofilm formation in injection line, the wellbore, sulfur contamination, and combinations thereof.

14. The process of claim 11, wherein said risk is nutrient contamination and nutrient analysis is conducted to identify nutrients with lower contaminants level and selected from the group consisting of nitrogen, sulfur, or other contaminant.

15. The process of claim 11, wherein said risk is selected from the group consisting of biofilm formation, biomass plugging, sludge development, and combinations thereof and biofilm inhibitors are screened to identify a biofilm inhibitor that controls biofilm formation in the mixing tank, the storage tank, the injection line, injection wellbore and combinations thereof.

16. The process of claim 11, wherein said risk is sludge development in the mixing tank, storage tank or both mixing tank and storage tank, and combinations of microbe inhibitors and inorganic treatments are screened to identify one or more individual inhibitors that control sludge formation in the mixing tank or the storage tank.

17. The process of claim 11 wherein said risk is selected from the group consisting of oxygen contamination, aerobic bacterial growth, and combinations thereof, and oxygen scavengers are screened to identify an oxygen scavenger that removes oxygen, does not inhibit anaerobic microbial growth, does not contain sulfur, and combinations thereof.

18. The process of claim 11 wherein said risk is oxygen contamination and said production water process is reviewed for potential oxygen contamination.

19. A process for modeling biogenic gas formation in vitro comprising:

a) characterization of organic carbon-rich substrates, one or more microbial organisms, and inorganic mineralogy in a subterranean formation;

b) determination of a injectate-water chemistry to promote biogas generation in the subterranean formation;

c) designing one or more monomers as a carbon source mimicking the organic-rich carbon substrate;

d) assaying microbial growth with injectate-water chemistry of the subterranean formation on one or more monomers mimicking the organic-rich carbon substrate; and

e) identifying one or more methanogenic pathways specific to the injectate-water chemistry and the organic-rich carbon substrate mimicked by one or more monomers.

20. The method of claim 19, wherein said one or more monomers are selected from the group consisting of one or more soluble lignins, alcohols, hydrocarbon monomers, esters, and combinations thereof.

21. The method of claim 19, wherein said microbial growth is assayed in an aqueous anaerobic culture, a solid culture media, a model sand-pack bioreactor, a model reservoir core sample, or combinations thereof.

22. The method of claim 19, wherein said one or more monomers are selected from the group consisting of syringic acid;

syringic acid methyl ester;

dimethyl phenol;

2,4-dimethyl phenol;

guaiacol;

protocatechuic acid;

vanillic acid;

isovanillic acid;

caffeic acid;

ferulic acid;

isoferulic acid;

dibenzofuran;

8-amino 2-naphthanol;

7-methoxy coumarin;

biphenyl 4-methanol;

1,1′

-biphenyl methyl;

methoxy biphenyl;

3-methoxy biphenyl;

dimethyl phenanthrene;

dimethyl fluoranthene;

8,9-dimethyl fluoranthene;

dimethylnapththalene;

dimethyl anthracene;

acetylene;

diacetylene;

vinylacetylene;

methyl naphthalene;

trimethyl naphthalene;

7-ethyl-1,4-dimethylazulene;

trimer-3-methoxy-4-benzyloxy-alpha-(2-methoxyphenoxy)-b-hydroxypropiophenone;

one or more compositions derived from the basic structure of lignin;

one or more compositions derived from the basic structure of kerogen; and

one or more compositions derived from hydrocarbons found in a subterranean carbonaceous formation.