Semester of Graduation
Master of Science in Petroleum Engineering (MSPE)
Craft and Hawkins Department of Petroleum Engineering
Development of civilization and the resulting quest for energy have led us to previously uncharted territory in exploration and production of fuel. As the demand continues to grow and conventional oil reserves become depleted, we are looking into unconventional resources such as gas hydrates. However, due to the volatile nature of the energy market and production technology yet to perfected, we are not able to fully utilize the potential of gas hydrates yet.
Reservoir characterization of hydrates have so far been limited to seismic mapping, well log interpretation and laboratory scale studies. This research uses numerical simulation to understand the geological and thermodynamic setting in which methane hydrates form in the subsurface and the reservoir quality changes that occur during and after the formation of hydrates. A reservoir model with sand and shale layers with a fault running through them is generated and flow of thermogenic methane gas as seen in the Gulf of Mexico subsurface is simulated using TOUGH+HYDRATE, a numerical code developed at the Lawrence Berkeley National Laboratory. The code uses an integrated finite difference method for space and time discretization to simulate multiphase flow in a geological system. The model was created using a specific MATLAB code for this research. Sensitivities on boundary conditions, fault angles, flow rate and reservoir properties are performed to study the formation process of methane hydrates.
The simulation results show that the hydrate formation depends on the reservoir rock and flow parameters. The geobody distribution of hydrate was highly affected by permeability, stratigraphy, fault angles and the boundary conditions, whereas, the saturation was impacted by pore-water salinity and flow rate of the gas into the reservoir. Numerical simulation of hydrate formation and the study of the reservoir properties are an important aspect of reservoir characterization for hydrates, which can be used for production planning of methane gas from these reserves. A more robust numerical code must be developed for a reservoir scale modeling of hydrate formation to simulate detailed complexities.
Dhakal, Sulav, "Thermogenic Gas Hydrate Formation In Gulf of Mexico Offshore Environment- Results from Numerical Simulation" (2018). LSU Master's Theses. 4669.