Methane Production from Gas-Hydrate Using Depressurization Method

• Main Author: Oragui, O.C. (author)
• Other Authors: Rudolph, E.S.J. (mentor)
• Format: Master Thesis
• Language: English
• Published: 2010
• Subjects: gas hydrates; gas production; multiple wells; horizontal wells; permafrost
• Online Access: http://resolver.tudelft.nl/uuid:d4612463-e74d-4891-8f70-86fcdf9e1a8f

Gas hydrates are significant resource of natural gas existing both on-shore buried under the permafrost and off-shore buried under oceanic and deep lake sediments. Earlier studies have demonstrated that large volumes of gas can be produced from gas hydrate accumulations by means of depressurization-induced dissociation using vertical wells. In this study gas hydrate production from a class-3-hydrate reservoir is investigated, on how the production results change if a homogeneous or a heterogeneous reservoir is used for the simulations. The production is by means of a vertical well drilled at the edge of the reservoir. Additionally, it has been studied how the placement of a vertical well and the number of vertical wells and their spacing influences the production. Also the efficiency of producing from a single horizontal well is studied and compared to the results of simulations with vertical wells. It was observed that the permeability of the reservoir has a strong impact on how the methane hydrates dissociate in the reservoir. Comparing the production data and how the reservoir has been swept of gas hydrates for the different scenarios employing various kind and amounts of well, it can be concluded that the scenario with two vertical wells is the most efficient scenario studied giving the most efficient production, low water production also because unwanted gravity segregation could be avoided. Petroleum Engineering and Geosciences Petroleum Engineering and Geosciences Civil Engineering and Geosciences