Thermogenic gas hydrates formation in Offshore environments - Results from numerical simulations
Document Type
Conference Proceeding
Publication Date
1-1-2018
Abstract
Development of human civilization and the growing demand for energy, as oil reserves around the world continue to deplete, have driven us to start producing from unconventional resources. Gas hydrates is one of the unconventional sources that has excited researchers and energy producers alike due to its immense potential. Numerous studies have shown the presence of gas hydrates in sea beds around the world including Gulf of Mexico. The study of hydrate formation in the Gulf of Mexico is an important step towards recognizing the potential of gas production from these reserves. However, such studies have been limited to seismic mapping and laboratory scale studies, and numerical modeling of hydrate formation has not been studied to quantify these reserves. This study intends to understand the geological and thermodynamic setting in which gas hydrates form in the subsurface and the associated reservoir quality changes (porosity/permeability) as hydrates form. A geological model, representative of the Gulf of Mexico subsurface, with sand and shale layers with a fault running through them is generated. Thermogenic methane gas flow up the fault is simulated using TOUGH+HYDRATE, a numerical code developed at the Lawrence Berkeley National Laboratory. The code uses integral finite difference method for space and time discretization for modeling multiphase flow. The flow geometry is generated using a MATLAB code developed specifically for this study. Sensitivities on fault angle, flow rate and reservoir properties are simulated to study the hydrate formation process. Results from the simulation predict that initiation of gas hydrates in the reservoirs appear to directly correlate to increased pressures in the pore spaces as the fluids move up through faults and invade the adjacent formations. Permeability and porosity of the hydrate formation zone decrease as solid hydrates form in the pores. Numerical simulation of gas hydrate formation and the study of rock and fluid flow properties during hydrate formation thus can be used as an important reservoir characterization tool, which can be used for estimation of the hydrate reserves as well as determination of well placement and production strategies.
Publication Source (Journal or Book title)
Proceedings of the Annual Offshore Technology Conference
First Page
2795
Last Page
2808
Recommended Citation
Dhakal, S., & Gupta, I. (2018). Thermogenic gas hydrates formation in Offshore environments - Results from numerical simulations. Proceedings of the Annual Offshore Technology Conference, 4, 2795-2808. https://doi.org/10.4043/29058-ms
