In-situ microbial oxygen generation and hydrocarbon conversion in a hydrocarbon containing formation

Abstract

A method for in-situ microbial oxygen generation in an underground hydrocarbon containing formation comprises: injecting into the formation an oxygen generating composition comprising thermophilic chlorate reducing micro-organisms, such as bacteria of the genus Archaeoglobus, Geobacillus and/or Thermus , which multiply at a temperature of at least 60° C.; and inducing the multiplied micro-organisms to convert the hydrocarbons and/or other pore fluid components in-situ into transportable or disposable products

1 . A method for in-situ oxygen generation in an underground hydrocarbon containing formation, the method comprising injecting into the formation an oxygen generating composition which releases oxygen (O 2 ) by reduction of chlorate (ClO 3 —), wherein:
 the formation has a temperature of at least 60° C.; 
 the composition comprises thermophilic chlorate reducing micro-organisms which multiply at an ambient temperature of at least 60° C.; and 
 the multiplied thermophilic chlorate reducing micro-organisms convert the hydrocarbons and/or other pore fluids in-situ into transportable or disposable products. 
 
     
     
         2 . The method of  claim 1 , wherein the thermophilic chlorate reducing micro-organisms comprise bacteria of the genus  Archaeoglobus, Geobacillus  and/or  Thermus , which use hydrogen (H) and electrons (e) provided by hydrocarbons, volatile fatty acids and/or other pore fluids in the formation followed by dismutation of chlorite (ClO 2   − ) by the micro-organisms on the basis of the reactions:
   ClO 3   − +2H + +2 e ->ClO 2   − +H 2 O     ClO 2   − ->Cl − +O 2      
     
     
         3 . The method of  claim 2 , wherein the thermophilic chlorate reducing micro-organisms multiply at an ambient temperature of at least 80° C. and comprise bacteria of the genus  Archaeoglobus fulgidis.    
     
     
         4 . The method of  claim 1 , wherein the oxygen generating composition comprises perchlorate (ClO 4 ) from which chlorate is generated using electrons released by the volatile fatty acids, hydrocarbons or other pore fluid components as electron donor on the basis of the following reaction:
   ClO 4   − +2H + +2 e ->ClO 3   − +H 2 O.   
     
     
         5 . The method of  claim 4 , wherein the hydrocarbons comprise viscous crude oil and/or other long chain hydrocarbons and the bacteria comprise crude oil degrading aerobic bacteria, such as bacteria of the genus  Geobacillus, Thermus  and/or other bacteria that convert long chain hydrocarbons into short chain hydrocarbons being indigenous to the formation of introduced by injection. 
     
     
         6 . The method of  claim 5 , wherein the multiplied bacteria dissociate crude oil from the formation by microbial dismutation of chlorite for the partial biotic and abiotic aerobic conversion of oil. 
     
     
         7 . The method of  claim 5 , wherein the multiplied bacteria dissociate viscous crude oil from the formation by microbial dismutation of chlorite for the partial biotic and abiotic aerobic conversion of oil and the method is used to enhance crude oil recovery from the formation. 
     
     
         8 . The method of  claim 1 , wherein the other pore fluids comprise natural gas contaminants, such as CO 2  and/or H 2 S, and the micro-organisms comprise bacteria of the genus  Sulfolobus, Ferroglobus, Thiobacillus, Thiomicrospira  or other genera able to convert natural gas contaminants. 
     
     
         9 . The method of  claim 8 , wherein the formation comprises a H 2 S containing pollutant from which the oxygen generates more oxidized sulfur compounds like elemental sulfur, poly sulfide, poly thionates and H 2 SO 4 . 
     
     
         10 . The method of  claim 1 , wherein the other pore fluid components comprise hydrogen ions, acetate, propionate or butyrate and/or other volatile fatty acids and the injected chemical comprises perchlorate, chlorate and/or chlorite and another chemical, which can serve as electron acceptor or oxygen source, such as oxygen, nitrate, nitrite and hydrogen peroxide in order to ensure deep placement of the perchlorate, chlorate and/or chlorite into the formation. 
     
     
         11 . The method of  claim 10 , wherein composition is injected either continuously or pulse-wise into the formation to ensure deep placement of the nitrate, nitrite, oxygen, perchlorate, chlorate or alternative electron acceptors into the formation. 
     
     
         12 . The method of  claim 1 , wherein the micro-organisms are bacteria that are either indigenous to the formation and/or introduced by injection into the formation. 
     
     
         13 . The method of  claim 1 , wherein the micro-organisms comprise a single species microorganism or a mixture and/or consortia of micro-organisms. 
     
     
         14 . The method of  claim 1 , wherein the micro-organisms are after a period of time substituted by single or multiple enzyme samples that can be water soluble or added as immobilized structures, such as bio-nano particles and/or the micro-organisms are either present in or introduced into the formation as highly active microbes or as spores, cysts or encapsulated micro-organisms. 
     
     
         15 . The method of  claim 1 , wherein the micro-organisms either perform the microbial conversion of perchlorate via chlorate and chlorite to chloride and oxygen (or parts thereof) or the microbial conversion of hydrocarbons or natural gas contaminants or microorganism that comprise both the perchlorate/chlorate/chlorite as well as the hydrocarbon conversion/natural gas contaminant conversion activity, and/or the micro-organisms contain key enzymes from a nitrate-reduction and/or chlorate-reduction pathway such as perchlorate reductase, chlorate reductase, chlorite dismutase, nitrate reductase or nitrate reductase or combinations thereof.