Hydrogen production, storage and recovery
AssigneeTerraH2 LLC
InventorsEva Vinegar, Harold J. Vinegar
Life of this patent
Estimating the term…
Abstract
A method for operating a kerogen-rich unconventional gas reservoir characterized by there being multiple hydraulically-fractured wells drilled thereinto comprises: recovering a methane-containing gas from a first hydraulically-fractured well drilled into the gas reservoir, steam-methane reforming the recovered methane-containing gas to yield a hydrogen gas and an inorganic carbon-containing gas, injecting at least a portion of the hydrogen gas into a second hydraulically-fractured well drilled into the gas reservoir, and injecting at least a portion of the inorganic carbon-containing gas into a third hydraulically-fractured well drilled into the gas reservoir.
Claims20
A method of storing and subsequently recovering hydrogen gas in a kerogen-rich, hydraulically-fractured unconventional gas reservoir, the method comprising:
- a. sampling, at a plurality of times, a methane-containing gas recovered from the geological formation through a horizontal wellbore;
- b. determining, from each sampling, an isotopic signature of a molecular component in the sampled methane-containing gas, the isotopic signature being based upon an isotope ratio;
- c. responsively to and contingent upon detecting an increase in the isotopic signature of at least two successive samplings, injecting hydrogen gas through the wellbore into the geological formation at a pressure higher than a shut-in gas pressure;
- and
- d. recovering, through the wellbore, a hydrogen-containing gas having an H2 molar fraction of at least 85%.
A method of storing and subsequently recovering hydrogen gas in a kerogen-rich unconventional gas reservoir, the method comprising:
- a. injecting a fracturing fluid through a horizontal wellbore into the geological formation to cause fracturing within the gas reservoir;
- b. recovering a methane-containing gas through the wellbore;
- c. monitoring an isotopic signature respective of at least one molecular component of the recovered methane-containing gas;
- d. determining an isotopic-signature trigger criterion at or above which hydrogen injected into the geological formation is subsequently recoverable in a hydrogen-containing gas having an H2 molar fraction of at least 85%;
- e. responsively to and contingent upon reaching an isotopic-signature trigger criterion based upon the monitored isotopic signature, injecting hydrogen gas through the wellbore into the geological formation at a pressure higher than a shut-in gas pressure at a wellhead;
- and
- f. recovering, through the wellbore, a hydrogen-containing gas having an H2 molar fraction of at least 85%.
Dependencies are inferred from the claim text.