DOE/NETL Methane Hydrate Projects
Properties of Hydrate-Bearing Sediments Subjected to Changing Gas Compositions Last Reviewed 6/30/2015

ESD12-011

Goal
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).

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

Background
A number of studies have investigated the impact of injecting CO2 and CO2-nitrogen N2 mixtures into methane hydrate for the purpose of sequestering CO2 and releasing methane (CH4), and review articles have been published summarizing the literature. Most of these studies have investigated the fundamental physical/chemical nature of the exchange of CO2 and/or N2 with CH4 in the clathrate. These studies have helped identify the limits of the effectiveness of CO2 injection into methane hydrate for the purposes of methane production and CO2 sequestration.

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.

Impact
The primary benefits of this lab-based research are improved empirical relationships among physical, chemical, mechanical, and hydrologic property changes in methane hydrate-bearing sediments subjected to injection of CO2and N2, which will assist in understanding the results of hydrate production field test data.

Accomplishments (most recent listed first)

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 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 (June 2015)
Budget period 3 activities are ongoing. Progress has been delayed due to personnel transitions, but new personnel is now in place and the preparations of equipment and materials for the planned testing of a layered hydrate system is nearing completion. Over the next month researchers will initiate the planned experiment in which they will attempt to monitor heat flux within the system both parallel and perpendicular to the applied bedding. In addition, discussions are currently underway to define additional activities to be conducted under Budget Period 4 of the project which is expected to start in July 2015.

Project Start: June 1, 2012
Project End: TBD

Project Cost Information: 
DOE Contribution: $280,000; Recipient Contribution: $0

Contact Information:
NETL – Richard Baker (Richard.Baker@netl.doe.gov)
LBNL –Timothy J. Kneafsey (tjkneafsev@lbl.gov)
If you are unable to reach the above personnel, please contact the content manager.

Additional Information

Research Performance Progress Report [PDF-188KB] October - December, 2014

Research Performance Progress Report [PDF-251KB] July, 2013 - April, 2014

Research Performance Progress Report [PDF-140KB] 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


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