US 5,093,236 A · Microbiological oil prospecting

Abstract

This invention provides methods and systems for prospecting for subterranean oil and gas deposits by detecting the presence of hydrocarbon-consuming microorganisms in soil samples taken from a field of interest for production. A preferred method of this invention comprises suspending and diluting each soil sample in mineral salt solution, combining the sample with a selective growth, substrate such as an alcohol or aldehyde, and an oxidation-reduction dye in a gas-tight tube, incubating the sample and measuring the color change of the dye. Advantages of this system include: results obtained in short times (24 to 72 hours), substantially eliminates false positives, accurate results particularly when a spectrophotometer is used to measure the color changes, and it is automatable with computer controlled systems for processing samples, reading the color changes and calculating and plotting test results.

Claims17

Dependent claims

Method for microbiological prospecting for oil or gas comprising the steps of:

(i) suspending a soil sample in a mineral salt solution;
(ii) adding to a gas-tight tube;
(a) said suspended soil sample,
(b) an additional portion of said mineral salt solution,
(c) a selective electron-donating growth substrate capable of providing electron-donating potential for a hydrocarbon-consuming microorganism;
and
(d) an oxidation-reduction dye capable of indicating by a change in color a change in the redox potential caused by growth of a hydrocarbon-consuming microorganism;
(iii) sealing the tube and incubating the contents of the sealed tube to allow growth of a hydrocarbon-consuming microorganism present therein;
and
(iv) observing color change in the tube contents to determine the presence of a hydrocarbon-consuming microorganism in said soil sample.

7 more elements

Dependencies are inferred from the claim text.

Microbiological oil prospecting

Life of this patent

Microbiological oil prospecting

Life of this patent

Abstract

Claims17