DOE/NETL Methane Hydrate Projects
Properties of Hydrate-Bearing Sediments Subjected to Changing Gas Compositions Last Reviewed December 2017


The objective of this research is to measure physical, chemical, mechanical, and hydrologic property changes in methane hydrate-bearing sediments subjected to injection of carbon dioxide (CO2) and nitrogen (N2) effects of sediment layering, and the effects of relevant gradients (thermal, chemical (salinity), and capillary pressure).

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA 94720

Few studies have examined the hydrologic and physical/mechanical property changes that occur during a hydrate composition change. In the studies that have been conducted, researchers did not measure hydrologic properties; quantification of the effluent gas was crude and performed over a limited range of conditions (mostly dry hydrate) and failed to address important reservoir issues such as pressure increase upon injection and the effect of changes in gas composition in a system where the gas composition varies.

This research will investigate processes associated with the injection of N2, CO2, and mixtures of these gases into methane hydrate-bearing porous media under non-stirred batch and flow-through conditions, and will attempt to quantify the exchange kinetics of the N2 and CO2 replacement into methane hydrate using flow-through reactors and breakthrough curve analysis. Permeability will be measured to detect changes, and geophysical property changes will be measured using either the Split Hopkinson Resonant Bar apparatus or a flow-through vessel with p- and s- wave transducers in the end platens.

Much of the investigated hydrate-bearing sediments that are thought of as potential energy targets are contained in layered sediments, having sands and silts or clay layers. Few laboratory studies have studied these layered systems. Layering affects the local and global permeability to both gas and water, further affecting gas and water flow, the location of hydrate formation and dissociation, and the impact of pressure signals. Layered systems are by nature complex, and simplification is required in laboratory studies to generate conceptual models that can be expressed numerically to aid in predicting gas production and mechanical changes of the sediments. Early studies have used fine and coarse sand, and sandstone and sand layers. Few laboratory tests of gas hydrate dissociation from layered systems have been performed. Also few tests have been performed examining important gradients. Tests with better quantification of processes are needed. This effort will measure physical, chemical, mechanical, and hydrologic property changes in layered sediments containing methane hydrate, water, and gas.

In addition to the studies of layered systems, numerical simulation of flow and mechanical properties of hydrate-bearing sands at the multigrain scale will be conducted here to extend earlier work by LBNL.

The primary benefits of this lab-based research is the provision of critical information for interpreting other laboratory and field tests including injection of CO2 and N2 into methane hydrate-bearing reservoirs, and production of methane from layered hydrate-bearing sediments, and systems under thermal, chemical, or capillary pressure gradients. Questions asked and answered on this project will be from a reservoir perspective understanding that many nonideal conditions can exist.

Accomplishments (most recent listed first)

Budget Period 6 (July 2017 – June 2018)

  • None to date 

Budget Period 5 (July 2016 – December 2017)

  • Generated a preliminary working version of a new permeability code to be used in prediction of the behavior of a hydrate-bearing medium based on X-ray micro CT and three hydrate habits.
  • Completed multiple tests on the hydrate dissociation point in saline systems providing indication that brine systems result in a hydrate equilibrium range rather than sharp equilibrium points.

Budget Period 4 (July 2015 – June 2016) 

  • Completed development of new lab pressure cell with increased sample size and additional feed throughs to allow more efficient setup and control of additional temperature manipulation experiments. Completed investigation of the effect of thermal gradient and gradient oscillation on hydrate behavior using existing pressure cell.
  • Completed multiple tests to examine the effect of thermal gradient on hydrate system behavior. Additional changes are needed to better control temperature gradient.
  • Completed lab setup for experiments on gas production from layered hydrate system and conducted initial experimental runs.
  • Completed a new system for the automated calculation of bulk and shear modulus for sub-volumes of a larger 3D image sequence as part of the effort focused on grain scale computation of HBS properties using MicroCT images.
  • Developed MATLAB interface to allow utilization of ELAS3D finite element code in an automated context to be applied to evaluation of elastic properties of models of hydrate bearing sediments.

Budget Period 3 (June 2014 – June 2015)

  • Obtained all materials required for conducting a test of a layered system and working to resolve leak path issues for the experimental setup.
  • Rebuilt hydrate pressure vessel.
  • Redesigned and built new temperature control jacket allowing Teflon coating of pressure vessel to eliminate external corrosion.
  • Examined hydrate sample layering techniques using sand and available layered sandstone.

Budget Period 2 (June 2013 – May 2014)

  • Completed development of computational protocol to provide theoretical distribution of hydrates in an experimentally measured sediment matrix.
  • Developed the permeability and diffusivity calculation codes for use in grain-scale computation of hydrate-bearing sediment properties based on micro CT sample descriptions.
  • Completed initial experiments measuring kinetics of gas exchange between a CO2 / N2 mixture and existing CH4 hydrate in a system with excess free water and comparing it to a system without excess free water.

 Budget Period 1 (June 2012 – May 2013)

  • Completed and documented results of a series of lab tests to monitor changes (gas exchange rates, permeability, and geomechanical properties) in CH4 hydrate-bearing samples exposed to an N2/CO2 gas mixture.
  • Completed design and construction of an experimental system to measure kinetics of gas exchange in hydrate-bearing sediments.
  • Established a new laboratory set-up (including a new CT scanner) capable of performing and monitoring hydrate exchange kinetics experiments.
  • Please see the project page for ESD05-048 to view accomplishments from past, related efforts.

Current Status (December 2017)
Efforts under Budget Period 6 are just underway due to delay in access to researchers. Focus in the upcoming months will be to initiate new experimental activities focused on continued/refined investigation of layered gas hydrate systems, and initiation of experiments focused on the comparison of the effectiveness of vertical and horizontal wells for gas production within a layered hydrate-bearing system. Equipment and initial design of these planned experiments are available and experiments are expected to begin in early 2018.

Project Start: June 1, 2012
Project End: September 30, 2018

Project Cost Information: 
DOE Contribution: $685,000; Recipient Contribution: $0

Contact Information:
NETL – Richard Baker (
LBNL –Timothy J. Kneafsey (
If you are unable to reach the above personnel, please contact the content manager.

Additional Information

Quarterly Research Performance Progress Report [PDF] October - December, 2017

Research Performance Progress Report [PDF] Period Ending September, 2017

Research Performance Progress Report [PDF] Period Ending June, 2017

Research Performance Progress Report [PDF] Period Ending April, 2016

Research Performance Progress Report [PDF] October - December, 2014

Research Performance Progress Report [PDF] July, 2013 - April, 2014

Research Performance Progress Report [PDF] July - September 2013

Topical Report : Behavior of Methane Hydrate Bearing Sediments Subjected to Changing Gas Composition [PDF-1.55MB]

Graphical representation of system to measure kinetics of gas exchange in hydrate-bearing sediments

Experimental system shown with reactor vessel inside of CT scanner