Process-based approach for the detection of deep gas invading the surface

US9645129B2 · kind B2 · utility

Assignee

• The Board of Regents of the University of Texas System · US

Inventors

• Katherine Romanak · Austin, US
• Philip Bennett · London, GB

Key dates

• Filing date: Jun 27, 2014
• Grant date: May 9, 2017
• Expiry date: Oct 20, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N33/24
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The present invention includes a method for determining the level of deep gas in a near surface formation that includes: measuring CO2, O2, CH4, and N2 levels in percent by volume from one or more surface or near surface geological samples; adding the water vapor content to the measured CO2, O2, CH4, and N2 levels in percent by volume; normalizing the gas mixture to 100% by volume or 1 atmospheric total pressure; and determining the ratios of: O2 versus CO2 to distinguish in-situ vadose zone CO2 from exogenous deep leakage CO2; CO2 versus N2 to distinguish whether CO2 is being removed from the near surface formation or CO2 is added from an exogenous deep leakage input; or CO2 versus N2/O2 to determine the degree of oxygen influx, consumption, or both; wherein the ratios are indicative of natural in situ CO2 or CO2 from the exogenous deep leakage input.