Microbial enhanced oil recovery methods

Abstract

The present invention is directed to the field of microbial enhanced oil recovery (MEOR). In particular, the invention focuses on new, efficient, economical and environmentally safe microbial methods to enhance oil recovery in existing oil reservoirs, as well as microorganisms useful in such methods.

I claim: 
     
         1 . A microorganism that (i) is a halophile, and (ii) is deficient in its ability to degrade short chain hydrocarbons of about 12 carbons or less. 
     
     
         2 . The microorganism of  claim 1  which is an obligatory halophile. 
     
     
         3 . The microorganism of  claim 2  that is an archaeon or a bacterium. 
     
     
         4 . The microorganism of  claim 3  which is an archaeon. 
     
     
         5 . The microorganism of  claim 1  that naturally has at least one of properties (i) and (ii). 
     
     
         6 . The microorganism of  claim 1  that is engineered to have at least one of properties (i) and (ii). 
     
     
         7 . The microorganism of  claim 1  which is able to grow in a salinity of about 5% or higher. 
     
     
         8 . The microorganism of  1  which is additionally inhibited in acquiring the ability to grow at salinity below about 5% from microorganisms indigenous in or contaminating an oil reservoir. 
     
     
         9 . The microorganism of  claim 1  which is additionally deficient in its ability to degrade hydrocarbons of about 20 carbons or less. 
     
     
         10 . The microorganism of  claim 1  which additionally has the ability to utilize aromatic hydrocarbons. 
     
     
         11 . The microorganism of  claim 1  which additionally has the ability to utilize hydrocarbon chains of greater than 12 carbons. 
     
     
         12 . The microorganism of  claim 1  which additionally has the ability to utilize hydrocarbons containing sulfur. 
     
     
         13 . The microorganism of  claim 1  which additionally has the ability to utilize modified hydrocarbons containing nitrogen. 
     
     
         14 . The microorganism of  claim 1  which additionally has the ability to utilize simple carbons from the group comprising; glucose, sucrose, mannose, starch, glycerin, organic acids, and other simple sugars. 
     
     
         15 . The microorganism of  claim 1  which additionally has the ability to produce surfactants. 
     
     
         16 . The microorganism of  claim 1  which additionally has the ability to produce extra cellular polymers. 
     
     
         17 . The microorganism of  claim 1  which (i) contains functional genes for the metabolism of high molecular weight hydrocarbons; (ii) lacks functional genes for the transport and oxidation of short chain alkanes at the cell membrane; (iii) contains functional genes for the production of surfactants; and (iv) is regulated to express said functional genes and grow in a high salt environment within an oil reservoir. 
     
     
         18 . A culture or consortium comprising a microorganism of  claim 1  or  claim 17 . 
     
     
         19 . A culture or consortium consisting essentially of microorganisms according to  claim 1  or  claim 17 . 
     
     
         20 . A culture or consortium consisting of microorganisms according to  claim 1  or  17 .