Control of fluid flow during treatment of subterranean sites using well fluid injection

Abstract

Disclosed herein is a method to control distribution of injected microorganisms, nutrients or other chemical treatment fluids from a single injection well to multiple production wells. The sweep efficiency is improved preventing premature production of fluids from production wells with short breakthrough times. This is a useful technique for treatment of subterranean target sites for practice of Microbial Enhanced Oil Recovery and bioremediation.

1 . A method for treatment of a subterranean target site comprising the steps of:
 a) determining fluid flow patterns of injection fluid between an injection well and one or more production wells in the subterranean site;   b) injecting a well treatment fluid in the subterranean site; and   c) controlling the distribution of the well treatment fluid amongst the production wells,   wherein oil recovery is improved.   
     
     
         2 . The method of  claim 1  wherein determining fluid flow patterns of injection fluid is by reservoir modeling, tracer testing, or approximation methods, 
     
     
         3 . The method of  claim 1  wherein controlling the distribution of the well treatment fluid is by selective shut off or flow restriction of one or more production wells. 
     
     
         4 . The method of  claim 1  wherein the well treatment fluid is selected from the group consisting of a chemical treatment fluid, a polymer fluid, a surfactant fluid, a high pH fluid, a low salt fluid, and combinations thereof. 
     
     
         5 . The method of  claim 4  wherein the chemical well treatment fluid is a nutritional chemical fluid for feeding native microorganisms in said subterranean target site. 
     
     
         6 . The method of  claim 4  wherein the chemical treatment fluid is a suspension of exogenous microorganisms in a nutritional chemical fluid. 
     
     
         7 . The method of  claim 4  wherein said polymer fluid consists of carboxymethylcellulose, hydroxyethylcellulose, carboxymethylhydroxyethyl-cellulose, guar gum, hydroxypropyl guar. carboxymethylhydroxypropyl guar, polyacrylamide, polyamines, xanthan, polysaccharides or polyvinyl-alcohol derivatives, or a combination therefrom. 
     
     
         8 . The method of  claim 4  wherein said surfactant consists of anionic sulfonates, nonionics (ethylene oxide derivatives), quaternary ammonium compounds, fluorosurfactants, amphoterics or glycol ethers, or a combination therefrom. 
     
     
         9 . The method of  claim 4  wherein said high pH fluid comprises a material with a pKa greater than 10, wherein the material consists of sodium silicate, sodium hydroxide or sodium carbonate, or a combination therefrom. 
     
     
         10 . The method of  claim 6  wherein the exogenous microorganisms comprise one or more species of:  Pseudomonas, Bacillus, Actinomycetes, Acinetobacter, Arthrobacter, Schizomycetes, Corynebacteria, Achromobacteria, Arcobacter, Enterobacteria, Nocardia, Saccharomycetes, Schizosaccharomyces, Vibrio, Shewanella, Thauera, Petrotoga, Microbulbifer, Marinobacteria, Fusibacteria , and  Rhodotorula.    
     
     
         11 . The method of  claim 4  wherein a combination of polymer, surfactant, and high pH fluids is used together. 
     
     
         12 . The method of  claim 4  wherein polymer, surfactant and high pH fluids are used in sequence.