Gas production enhancement effect of underlying gas on methane hydrates in marine sediments by depressurization

Summary Sedimentary methane hydrates contain a vast amount of untapped natural gas that can be produced through pressure depletion. Several field pilots have proved the concept with days to weeks of operation, but the longer-term response remains uncertain. This paper investigates the parameters affecting the rate of gas recovery from methane-hydrate-bearing sediments. The recovery of methane gas from hydrate dissociation through pressure depletion was studied at different initial hydrate saturations and different constant production pressures in cylindrical sandstone cores. Core-scale dissociation patterns were mapped with magnetic resonance imaging (MRI), and pore-scale dissociation events were visualized in a high-pressure micromodel. Key findings from the gas-production-rate analysis are that the maximum rate of recovery is only to a small extent affected by the magnitude of the pressure reduction below the dissociation pressure, and that the hydrate saturation directly affects the rate of recovery, where intermediate hydrate saturations (0.30 to 0.50) give the highest initial recovery rate. These results are of interest to anyone who evaluates the production performance of sedimentary hydrate accumulations and demonstrate how important accurate saturation estimates are to prediction of both the initial rate of gas recovery and the ultimate-recovery efficiency.

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Evaluation of the gas production enhancement effect of hydraulic fracturing on combining depressurization with thermal stimulation from challenging ocean hydrate reservoirs

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2020.103621 ◽

2020 ◽

Vol 83 ◽

pp. 103621

Author(s):

Xiuping Zhong ◽

Dongbin Pan ◽

Lianghao Zhai ◽

Ying Zhu ◽

Han Zhang ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Gas Production ◽

Thermal Stimulation ◽

Enhancement Effect ◽

Hydrate Reservoirs

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Gas production from methane hydrates upon thermal stimulation; an analytical study employing radial coordinates

Energy ◽

10.1016/j.energy.2019.116815 ◽

2020 ◽

Vol 194 ◽

pp. 116815 ◽

Cited By ~ 2

Author(s):

M. Roostaie ◽

Y. Leonenko

Keyword(s):

Analytical Study ◽

Gas Production ◽

Thermal Stimulation ◽

Methane Hydrates

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Gas Production from Methane Hydrates in a Dual Wellbore System

Energy & Fuels ◽

10.1021/ef501769r ◽

2014 ◽

Vol 29 (1) ◽

pp. 35-42 ◽

Cited By ~ 32

Author(s):

Matilda Loh ◽

Jun Lin Too ◽

Simon Falser ◽

Praveen Linga ◽

Boo Cheong Khoo ◽

...

Keyword(s):

Gas Production ◽

Methane Hydrates

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Estimation of the global inventory of methane hydrates in marine sediments using transfer functions

Biogeosciences Discussions ◽

10.5194/bgd-9-581-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 581-626 ◽

Cited By ~ 4

Author(s):

E. Piñero ◽

M. Marquardt ◽

C. Hensen ◽

M. Haeckel ◽

K. Wallmann

Keyword(s):

Transfer Function ◽

Organic Carbon ◽

Marine Sediments ◽

Gas Hydrates ◽

Gas Hydrate ◽

Large Scale ◽

Transfer Functions ◽

Carbon Accumulation ◽

Methane Hydrates ◽

Transport Reaction

Abstract. The accumulation of gas hydrates in marine sediments is essentially controlled by the accumulation of particulate organic carbon (POCar) which is microbially converted into methane, the thickness of the gas hydrate stability zone (GHSZ) where methane can be trapped, and the delivery of methane from deep-seated sediments by ascending pore fluids and gas into the GHSZ. Recently, Marquardt et al. (2010) developed a transfer function to predict the gas hydrate inventory in diffusion-controlled geological systems based on POCar and GHSZ. We present a new parameterization of this function and apply it to global datasets of bathymetry, heat flow, seafloor temperature and organic carbon accumulation estimating a global mass of only 91 Gt of carbon (GtC) stored in marine methane hydrates. Seepage of methane-rich fluids is known to have a pronounced effect on gas hydrate accumulation. Therefore, we carried out a set of systematic model runs with the transport-reaction code in order to derive an extended transfer function explicitly considering upward fluid advection. Using averaged fluid velocities for active and passive margins, which were derived from mass balance considerations, this extended transfer function predicts the formation of gas hydrates along the continental margins worldwide. Different scenarios were investigated resulting in a global mass of sub-seafloor gas hydrates of 400–1100 GtC. Overall, our systematic approach allows to clearly and quantitatively distinguish between the effect of biogenic methane generation from POC and fluid advection on the accumulation of gas hydrate and hence, provides a simple prognostic tool for the estimation of large-scale and global gas hydrate inventories in marine sediments.

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Estimation of the global inventory of methane hydrates in marine sediments using transfer functions

Biogeosciences ◽

10.5194/bg-10-959-2013 ◽

2013 ◽

Vol 10 (2) ◽

pp. 959-975 ◽

Cited By ~ 95

Author(s):

E. Piñero ◽

M. Marquardt ◽

C. Hensen ◽

M. Haeckel ◽

K. Wallmann

Keyword(s):

Transfer Function ◽

Marine Sediments ◽

Gas Hydrates ◽

Gas Hydrate ◽

Large Scale ◽

Transfer Functions ◽

Methane Hydrates ◽

Continental Margins ◽

Transport Reaction ◽

Methane Generation

Abstract. The accumulation of gas hydrates in marine sediments is essentially controlled by the accumulation of particulate organic carbon (POC) which is microbially converted into methane, the thickness of the gas hydrate stability zone (GHSZ) where methane can be trapped, the sedimentation rate (SR) that controls the time that POC and the generated methane stays within the GHSZ, and the delivery of methane from deep-seated sediments by ascending pore fluids and gas into the GHSZ. Recently, Wallmann et al. (2012) presented transfer functions to predict the gas hydrate inventory in diffusion-controlled geological systems based on SR, POC and GHSZ thickness for two different scenarios: normal and full compacting sediments. We apply these functions to global data sets of bathymetry, heat flow, seafloor temperature, POC input and SR, estimating a global mass of carbon stored in marine methane hydrates from 3 to 455 Gt of carbon (GtC) depending on the sedimentation and compaction conditions. The global sediment volume of the GHSZ in continental margins is estimated to be 60–67 × 1015 m3, with a total of 7 × 1015 m3 of pore volume (available for GH accumulation). However, seepage of methane-rich fluids is known to have a pronounced effect on gas hydrate accumulation. Therefore, we carried out a set of systematic model runs with the transport-reaction code in order to derive an extended transfer function explicitly considering upward fluid advection. Using averaged fluid velocities for active margins, which were derived from mass balance considerations, this extended transfer function predicts the enhanced gas hydrate accumulation along the continental margins worldwide. Different scenarios were investigated resulting in a global mass of sub-seafloor gas hydrates of ~ 550 GtC. Overall, our systematic approach allows to clearly and quantitatively distinguish between the effect of biogenic methane generation from POC and fluid advection on the accumulation of gas hydrate, and hence, provides a simple prognostic tool for the estimation of large-scale and global gas hydrate inventories in marine sediments.

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Natural Gas Production from Methane Hydrate Deposits Using Clathrate Sequestration: State-of-the-Art Review and New Technical Approaches

Journal of Geological Research ◽

10.1155/2011/239397 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

Annick Nago ◽

Antonio Nieto

Keyword(s):

Carbon Dioxide ◽

Natural Gas ◽

Carbon Dioxide Emissions ◽

Methane Hydrate ◽

Field Studies ◽

Gas Production ◽

Methane Hydrates ◽

Methane Recovery ◽

Natural Gas Production ◽

Recovery Potential

This paper focuses on reviewing the currently available solutions for natural gas production from methane hydrate deposits using CO2 sequestration. Methane hydrates are ice-like materials, which form at low temperature and high pressure and are located in permafrost areas and oceanic environments. They represent a huge hydrocarbon resource, which could supply the entire world for centuries. Fossil-fuel-based energy is still a major source of carbon dioxide emissions which contribute greatly to the issue of global warming and climate change. Geological sequestration of carbon dioxide appears as the safest and most stable way to reduce such emissions for it involves the trapping of CO2 into hydrocarbon reservoirs and aquifers. Indeed, CO2 can also be sequestered as hydrates while helping dissociate the in situ methane hydrates. The studies presented here investigate the molecular exchange between CO2 and CH4 that occurs when methane hydrates are exposed to CO2, thus generating the release of natural gas and the trapping of carbon dioxide as gas clathrate. These projects include laboratory studies on the synthesis, thermodynamics, phase equilibrium, kinetics, cage occupancy, and the methane recovery potential of the mixed CO2–CH4 hydrate. An experimental and numerical evaluation of the effect of porous media on the gas exchange is described. Finally, a few field studies on the potential of this new gas hydrate recovery technique are presented.

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