Effect of Bed Deformation on Natural Gas Production from Hydrates

Mohamed Iqbal Pallipurath

doi:10.1155/2013/942597

Abstract

This work is based on modelling studies in an axisymmetric framework. The thermal stimulation of hydrated sediment is taken to occur by a centrally placed heat source. The model includes the hydrate dissociation and its effect on sediment bed deformation and resulting effect on gas production. A finite element package was customized to simulate the gas production from natural gas hydrate by considering the deformation of submarine bed. Three sediment models have been used to simulate gas production. The effect of sediment deformation on gas production by thermal stimulation is studied. Gas production rate is found to increase with an increase in the source temperature. Porosity of the sediment and saturation of the hydrate both have been found to significantly influence the rate of gas production.

Highlights

Energy demand is on the rise globally but the production rates of major fossil fuels are going down
Natural gas hydrate (NGH) is one of the possible energy sources to meet these requirements. It is a highly condensed form of natural gas formed by capture of natural gas molecules in a cage of water molecules: each cubic meter of natural gas hydrate yields about 160 cubic meter of gas at STP
The heat source temperature has a marked influence upon the rate of production of gas, with a factor of ∼50% increase in production with 12.5% increase in temperature

Summary

Mohamed Iqbal Pallipurath

Mechanical Engineering Department, TKM College of Engineering, Kollam, Kerala 691005, India. This work is based on modelling studies in an axisymmetric framework. The thermal stimulation of hydrated sediment is taken to occur by a centrally placed heat source. The model includes the hydrate dissociation and its effect on sediment bed deformation and resulting effect on gas production. A finite element package was customized to simulate the gas production from natural gas hydrate by considering the deformation of submarine bed. Three sediment models have been used to simulate gas production. The effect of sediment deformation on gas production by thermal stimulation is studied. Gas production rate is found to increase with an increase in the source temperature. Porosity of the sediment and saturation of the hydrate both have been found to significantly influence the rate of gas production

Introduction

Heat Heat

Poroelastic Viscoelastic Viscoplastic

Conclusions

Findings

Gas extraction methods Depressurization