Publication Date:
2017-03-22
Description:
Gas production from gas hydrate-bearing sediments has been attracting global interests because of its potential to meet growing energy demand. Methane (CH4) gas can be extracted from CH4 hydrates by depressurization, thermal stimulation or chemical activation. However, it has never been produced on a commercial scale and the past field trials faced premature termination due to the technical difficulties such as excessive sand flow into the well, a phenomenon known as sand production. One exception is the trial at the Ignik Sikumi, Alaska in 2012, which was conducted by chemical activation followed by depressurization. During the trial, initial sand production ceased after two weeks while CH4 gas production continued for five weeks. The mitigation of sand production is deemed attributed to mechanical or hydraulic effects through formation of CO2-rich gas hydrates. This incident has highlighted the favorable effect of CO2 hydrate formation and needs to incorporate the chemo-processes into existing thermo-hydro-mechanical formulations. This paper presents an analytical formulation to capture the coupled thermo-hydro-chemo-mechanical behavior of gas hydrate-bearing sediments during gas production via CO2 injection. The key features of the formulation include hydrate formation and dissociation, gas dissolution and multiphase flow for both CH4 and CO2, facilitating CH4-CO2 hydrate conversion.
Type:
Book chapter
,
NonPeerReviewed
DOI:
10.1061/9780784480137.024
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