Influence of temperature on methane hydrate formation.

Area of Science:

• Geochemistry
• Physical Chemistry
• Earth Science

Background:

• Gas hydrate formation involves a phase transition of liquid water.
• Temperature is a critical factor influencing hydrate formation kinetics and thermodynamics.
• Understanding temperature's role is vital for natural gas hydrate reservoir analysis.

Purpose of the Study:

• To investigate the influence of temperature on methane hydrate formation.
• To introduce a new indicator for the intrinsic driving force of hydrate formation.
• To analyze the relationship between temperature, formation driving force, and gas consumption.

Main Methods:

• Methane hydrate formation experiments conducted at three different temperatures (1.45°C, 6.49°C, 12.91°C).
• Application of stepwise pressurization modes.
• Calculation of the slope of gas flow rates against time (dνg/dt) as a driving force indicator.
• Quantification of gas consumed during different formation stages (nucleation, growth, decay).

Main Results:

• The driving force for hydrate formation exhibited an inverse relationship with temperature across all stages.
• The amount of gas consumed during formation was found to be proportional to temperature.
• Distinct temperature dependencies were observed for the formation driving force and the total gas uptake.

Conclusions:

• Temperature influences the intrinsic driving force and the total gas consumed in methane hydrate formation through separate mechanisms.
• Separate consideration of temperature's effect on formation processes and final gas content is necessary.
• Ambient temperature is a key parameter for explaining variations in gas hydrate configurations and saturations in natural reservoirs.