Geochemical methods for monitoring and evaluating microbial enhanced recovery operations

Patent metadata

Field	Value
Publication number	US-10132144-B2
Application number	US-201715668395-A
Country	US
Kind code	B2
Filing date	Aug 3, 2017
Priority date	Sep 2, 2016
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Described herein are methods and techniques that utilize molecular geochemistry and isotopic signatures to monitor microbial enhanced gas and oil recovery operations. The methods and techniques utilize multiply substituted isotopologue signatures, clumped isotope signatures, and/or position-specific isotope signatures of one or more byproducts of the microbial stimulation techniques to determine the effectiveness of a microbial stimulation technique.

First claim

The invention claimed is:

1. A method of producing hydrocarbons comprising:
(a) obtaining one or more samples from a well in a region of interest;
(b) analyzing the one or more samples to determine a baseline isotopic signature, wherein the baseline isotopic signature comprises one or more of multiply substituted isotopologue signatures, clumped isotope signatures, and position-specific isotope signatures;
(c) performing a microbial stimulation operation on the region of interest;
(d) obtaining one or more post-stimulation samples from the well;
(e) analyzing the post-stimulation sample to determine an induced isotopic signature, wherein the induced isotopic signature comprises multiply substituted isotopologue signatures, clumped isotope signatures, and/or position-specific isotope signatures;
(f) comparing the baseline isotopic signature and the induced isotopic signature;
(g) using the comparison to determine whether the type of hydrocarbons being produced from the well has changed, wherein the type of hydrocarbons being produced from the well comprises thermogenic hydrocarbons, biogenic hydrocarbons, and induced biogenic hydrocarbons; and
(h) updating or refining the microbial stimulation operation based on the type of hydrocarbons being produced from the well.

2. The method of claim 1 , wherein the sample comprises produced fluids from the well.

3. The method of claim 1 , wherein the sample comprises hydrocarbons.

4. The method of claim 1 , wherein the sample comprises one or more of biosurfactants, biopolymers, and organic acids.

5. The method of claim 1 , wherein the microbial stimulation operation comprises introducing nutrients into the region of interest.

6. The method of claim 5 , wherein the nutrients comprise one or more of molasses, nitrates, vitamins, and surfactants.

7. The method of claim 1 , wherein the microbial stimulation operation comprises introducing an exogenous microbial population to the region of interest.

8. The method of claim 7 , wherein the exogenous microbial population is introduced to the region of interest by injection of a solution comprising the exogenous microbial population in the well.

9. The method of claim 1 , wherein the comparison of the baseline isotopic signature and the induced isotopic signature comprises a comparison of the change in the 13 CH 3 D concentration.

10. The method of claim 1 , wherein the comparison of the baseline isotopic signature and the induced isotopic signature comprises a comparison of the change in the 12 CH 2 D 2 concentration.

11. The method of claim 1 , wherein the multiply substituted isotopologue signature, clumped isotope signature, or position-specific isotope signature is determined by:
modeling an expected temperature-concentration dependence of the isotopologues for a hydrocarbon species of interest;
measuring the concentration of isotopologues of the hydrocarbon species of interest present in the sample;
comparing the measured concentration of isotopologues with the expected concentration of isotopologues; and
converting the measured concentration of isotopologues to a storage temperature of the hydrocarbon species of interest.

12. The method of claim 1 , further comprising developing a new stimulation strategy based on the type of hydrocarbons being produced in the well.

13. The method of claim 1 , further comprising producing hydrocarbons.

14. A method of producing hydrocarbons comprising:
(a) obtaining one or more hydrocarbon samples from a well in a region of interest;
(b) analyzing the one or more samples to determine a baseline isotopic signature for a hydrocarbon species of interest, wherein the baseline isotopic signature comprises one or more of multiply substituted isotopologue signatures, clumped isotope signatures, and position-specific isotope signatures;
(c) performing a microbial stimulation operation on the region of interest, wherein the microbial stimulation operation comprises at least one of introducing nutrients into the region of interest or introducing an exogenous microbial population to the region of interest;
(d) obtaining one or more post-stimulation hydrocarbon samples from the well;
(e) analyzing the post-stimulation sample to determine an induced isotopic signature for the hydrocarbon species of interest, wherein the induced isotopic signature comprises multiply substituted isotopologue signatures, clumped isotope signatures, and/or position-specific isotope signatures;
(f) comparing the baseline isotopic signature and the induced isotopic signature to determine whether the type of hydrocarbons being produced from the well has changed, wherein the type of hydrocarbons being produced from the well comprises thermogenic hydrocarbons, biogenic hydrocarbons, and induced biogenic hydrocarbons; and
(g) modifying the microbial stimulation operation by at least one of changing the type of nutrients being introduced to the region of interest, changing the volume or rate of nutrients being introduced to the region of interest, and changing the community composition of the exogenous microbial population being introduced to the region of interest; wherein the modifying is based on the comparison of the baseline isotopic signature and the induced isotopic signature.

15. The method of claim 14 , wherein the nutrients comprise one or more of molasses, nitrates, vitamins, and surfactants.

16. The method of claim 14 , wherein the comparison of the baseline isotopic signature and the induced isotopic signature comprises a comparison of the change in the 13 CH 3 D concentration.

17. The method of claim 14 , wherein the comparison of the baseline isotopic signature and the induced isotopic signature comprises a comparison of the change in the 12 CH 2 D 2 concentration.

18. The method of claim 14 , further comprising producing hydrocarbons.

Assignees

• Lawson Michael
• Robinson Amelia C
• Stolper Daniel A
• Exxonmobil Upstream Res Co

Inventors

• Lawson Michael
• Robinson Amelia C
• Stolper Daniel A

Classifications

• E21B43/25

  Methods for stimulating production {(by vibrating earth formations E21B43/003)} · CPC title

• C09K8/90

  of natural origin, e.g. polysaccharides, cellulose · CPC title

• C12P39/00

  Processes involving microorganisms of different genera in the same process, simultaneously · CPC title

• G01V9/007

  by detecting gases or particles representative of underground layers at or near the surface (analysing earth materials G01N33/24; analysing gases per se G01N) · CPC title

• C12P1/00

  Preparation of compounds or compositions, not provided for in groups C12P3/00 - C12P39/00, by using microorganisms or enzymes · CPC title