DOE/NETL Methane Hydrate Projects
Numerical Studies for the Characterization of Recoverable Resources from Methane Hydrate Deposits Last Reviewed 6/17/2014

ESD12-010

Project Goal
The overall objective of this project is to conduct numerically-based studies to characterize and analyze recoverable resources from gas hydrate deposits, evaluate appropriate production strategies for both permafrost and marine environments, and analyze the geomechanical behavior of hydrate-bearing sediments, as well as provide support for DOE’s hydrate-related activities and collaborative projects.

Performer
Lawrence Berkeley National Lab (LBNL), Berkeley, CA 94720: model modifications and runs; project management

Background
TOUGH+/HYDRATE (pT+H) is a code developed by LBNL that simulates the behavior of hydrate-bearing geologic systems. By solving coupled equations of mass and heat balance, pT+H can model the non-isothermal gas release, phase behavior, and flow of fluids and heat under conditions typical of common natural methane (CH4) hydrate-bearing deposits in complex formations. TOUGH+/HYDRATE includes both an equilibrium and kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH4, hydrate, and water-soluble inhibitors such as salts or alcohols portioned among four possible phases (gas phase, liquid phase, ice phase, and hydrate phase) and up to five components (heat, hydrate, water, CH4, and water-soluble inhibitors). Hydrate dissociation or formation, phase changes, and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects, and inhibitor-induced effects. Under this project, LBNL is developing and maintaining pT+H as well as actively using the program to predict the behavior of hydrates and hydrate-bearing geologic systems in the laboratory or field, and from pore to regional scale.

Potential Impact
These numerical modeling efforts will allow hydrate scientists to better assess, identify, and predict the behavior of hydrate-bearing sediments under natural- and hydrate-production conditions for various hydrate occurrences in both Arctic and deepwater marine environments. The efforts will contribute to the planning and assessment of hydrate program field tests, and continue to define the feasibility of hydrates as an energy resource.

Accomplishments:

Budget Period 2 (June 2013 – June 2014)

  • Completed initial analysis and history matching efforts of the depressurization phase of the 2012 ConocoPhillips Ignik Sikumi gas hydrate production test.
  • Completion of simulations on the effectiveness of slanted wells in production of gas from highly stratified hydrate deposits and analysis of results. Manuscript preparation has not yet begun.
  • Completed a study of production from a large-scale extremely heterogeneous reservoir in contact with large aquifers in the GoM using both horizontal and vertical wells (paper currently in press in Transport in Porous Media)
  • Completed the simulation analysis of coupled flow, thermal, and geomechanical system response during gas production for sites in the GoM (GC955 and WR313) expanding on a prior OTC paper
  • Addition of tracking capabilities to TOUGH + HYDRATE code enabling tracking of properties, conditions, and flows throughout the simulation
  • Completed incorporating a new package of parallel solvers (PETC Package) into the unicode version of TOUGH + HYDRATE
  • Completed the simulation analysis of coupled flow, thermal, and geomechanical system response during gas production from a well representative of PBU L106 well (Alaska North Slope) using both horizontal and vertical wells (submitted for publication toSPE Journal)
  • In cooperation with the Korea Institute of Geosciences and Minerals, completed simulations in support of planning for a 2014 short-term production field test in the Ulleung Basin of the Korean East Sea including a base case, three different depressurization rates, sensitivity analyses on multiple parameters, and a fully coupled flow and geomechanics study. Results presented in a paper at OTC 2014. An expanded version of the OTC paper is under review for publication in SPE Journal of the Society of Petroleum Engineers.

Budget Period 1 (June 2012 – May 2013)

  • Developed a working prototype of a Unicode version of the TOUGH+ HYDRATE code (uT+H)
  • Publicly released new versions of both the serial and the parallel TOUGH+HYDRATE codes (with improved thermodynamics and thermophysical properties, and new control and output capabilities)
  • Completed two collaborative studies (with KIGAM, Korea) on the production potential, and corresponding geomechanical system behavior, of Korean marine hydrates in the Ulleung Basin (two related papers published or in review)
  • Developed and tested a two-way, fully-coupled flow-thermal-geomechanical simulator (involving TOUGH+HYDRATE and ROCMECH)
  • Published two papers on coupled flow-thermal-geomechanical processes in producing hydrate systems
  • Completed the largest numerical study ever conducted on the evaluation of the behavior of marine hydrate deposits
  • Completed studies on gas recoverability from the PBU-L106 site in Alaska
  • Published a chapter in Advanced Biofuels and Bioproducts on the status of gas production from hydrates.

For accomplishments from past, related efforts, please see the project page for FWP G308.

TOUGH+/Hydrate is available to commercial and non-commercial users from LBNL [external site]. Non-commercial licenses are available to academic and research institutions at reduced cost and free of charge for users working on U.S. government-sponsored research projects. Details on licensing and associated licensing costs can be found on the TOUGH+ licensing site [external].

Current Status (June 2014)
Budget Period 2 activities have been completed to the extent possible with available funds.  Much of the work performed has been documented through papers in print or manuscripts submitted for publication (see accomplishments section).  Initial activities focused on history matching of the depressurization phase of the 2012 Ignik Sikumi gas hydrate production trial showed mixed results.  Complexities in achieving a full match are believed to be the result of continuing release of CO2 and N2 during this latter depressurization phase.  The TOUGH+HYDRATE code is not able to capture the behavior of the complex hydrates that would likely be seen in the presence of these constituents.  Efforts are now underway to define a new set of activities for the next budget period of this FWP, which is expected to begin in early July 2014. 

Project Start: April 1, 2012
Project End: TBD

Project Cost Information:
DOE Contribution: $250,000; Recipient Contribution: $0

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

Additional Information

Research Performance Progress Report [PDF-109KB] June, 2013 - May, 2014

Research Performance Progress Report [PDF-387KB] April - December, 2012


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