Method and apparatus for treating fouled wells
Disclosed herein is a method and apparatus for treating biofouled wells with azide compounds, and/or for preventing biofouling in a well. The well is contacted with an amount of an azide compound effective for treating or preventing biofouling in the well.
1 . A method for treating a well comprising contacting the well with an effective amount of azide.
2 . The method of claim 1 , wherein the well is fouled and the amount of azide is effective for improving the hydraulic conductivity thereof.
3 . The method of claim 1 , wherein the well is not fouled and the amount of azide is effective for preventing the fouling thereof.
4 . The method of claim 1 , wherein the well is selected from the group consisting of an injection well, an extraction well, and a monitoring well.
5 . The method of claim 4 , wherein the well is used in an in situ remediation system.
6 . The method of claim 5 , wherein the in situ remediation system is used to remediate a contaminant selected from the group consisting of perchlorate, chlorate, and mixtures thereof.
7 . The method of claim 1 , wherein the azide is selected from the group consisting of salts of N 3 − and hydrazoic acid.
8 . The method of claim 7 , wherein the azide is selected from the group consisting of sodium azide, potassium azide, and ammonium azide.
9 . The method of claim 1 , wherein the azide is in an aqueous solution.
10 . The method of claim 7 , wherein the solution is buffered.
11 . The method of claim 7 , wherein the concentration of the azide is greater than about 75 mM.
12 . The method of claim 1 , wherein a pulse of azide is injected into the well.
13 . The method of claim 1 , wherein the hydraulic conductivity of the well after treatment is at least about 50% of the original hydraulic conductivity.
14 . The method of claim 1 , wherein the backpressure in the well is reduced by at least about 50%.
15 . The method of claim 1 , wherein the contacting with azide under automated control.
16 . A method for in situ remediation of a contaminant comprising:
injecting an electron donor into an injection well, wherein the injection well is in fluid communication with a water zone comprising a contaminant; and
injecting an azide into the injection well, wherein the amount of azide is effective to prevent and/or remedy fouling in the injection well.
17 . The method of claim 16 , wherein the electron donor is selected from the group consisting of citric acid and ethanol.
18 . The method of claim 16 , further comprising mixing the azide with water extracted from an extraction well located downgradient of the injection well.
19 . The method of claim 16 , wherein the contaminant is selected from the group consisting of perchlorate, chlorate, and mixtures thereof.
20 . The method of claim 16 , wherein the azide is selected from the group consisting of sodium azide, potassium azide, and ammonium azide.