Project Goal
The goal of this project is increased understanding of gas hydrate thermal properties through measurements on natural hydrate-bearing sediment cores and hydrate-bearing cores formed within laboratory pressure vessels.

Project Performers
Eilis Rosenbaum, NETL, Office of Research and Development
Ronald Lynn, NETL, RDS/Parsons
Dr. David Shaw, Geneva College

Project Location
National Energy Technology Laboratory, Pittsburgh, PA

Background
NETL utilizes a modified transient plane source (TPS) shown in Figure 1 using a technique originally developed by Gustafsson [1, 2] in a single-sided configuration (Figure 2). The TPS technique is capable of simultaneously determining both thermal conductivity and thermal diffusivity. The TPS serves both as a heat source and temperature sensing element during the measurements. This technique is suitable for small sample sizes utilizing Vishay Micro-Measurement, Inc.’s commercially available ETG-50B temperature sensor (Figure 1). The sensor is attached to PVC, which provides support for the sensor, especially during compaction experiments, and also allows thermal migration to progress to the in situ probe. This single-sided approach does not require large samples and it enables measurements to be made via surface contact with any sample.

	Figure 1: Vishay Micro-Measurements, Inc.'s temperature sensor, used in NETL's single-sided technique.		Figure 2: Single-sided (1 sided) TPS technique with the sensor adhered to PVC, as in NETL's arrangement, and the double-sided arrangement (2 sided).

Project Description
The experimental thermal properties measurement system developed and used for this research was designed to be mobile and adaptable for use with multiple scenarios. The technology and techniques can be used to simultaneously determine the thermal conductivity and thermal diffusivity of hydrate and hydrate-containing sediments using a single-sided measurement approach (i.e., the sensor contacts the sample on one side as opposed to being surrounded by the sample). The motivation for such a design was to create a mobile device suitable for use in other research facilities and, with some adaptations, for use in the field.

The best approach for determining the thermal properties of natural samples is to take measurements on undisturbed cores. The measurement approach and technology employed in this research accomplishes this important criterion. Pressure cores that have been transferred to a properly pressurized vessel will provide the best means to measure thermal properties of natural samples. The thermal properties device developed under this effort is being incorporated into reactors designed for CT scanning. X-ray CT scans will provide context to thermal property measurements by supplying information on the porosity and composition of the sample being measured.

Impact
Gas hydrate thermal properties are important parameters for understanding the behavior of natural gas hydrates. The techniques and technologies developed under this research enable measurement of these thermal properties in a non-destructive manner and can readily be used on hard or frozen sediment. Understanding these parameters will help researchers develop models and methods for predicting the behavior of gas hydrates in their natural environment for gas production or climate change scenarios.

Accomplishments

• Development of a technology/technique that provides a non-destructive means of measuring thermal properties of natural cores.
• Development of a technology/technique capable of being implemented into almost any device.
• Completion of thermal property measurements on pure methane hydrate and methane hydrate in sediments that have been formed in the laboratory.
• Installation of the thermal property sensor into several NETL pressure vessels, which can be placed in the CT scanner to enable visualization during thermal property measurement experiments.
• Ongoing collaborations with other groups to incorporate this technology/technique into other existing devices.

Project Status (March 2013)
This project is complete. A brief outline of key accomplishments is included below and a more detailed definition of project results can be found in the referenced articles, publications, and reports cited within the Methane Hydrate Program Bibliography [PDF]. Ongoing use of the techniques and technologies developed under this effort is documented in the current NETL ORD-Experimental Studies summey web page.

Project Duration
Project period covered is from ~2005 to 2011.

Project Funding
Project funding has totaled ~$1,006,000 over the performance period.

Additional Information:
In addition to the information provided here, a full listing of project related publications and presentations as well as a listing of funded students can be found in the Methane Hydrate Program Bibliography [PDF].

2008 Hydrate Peer Review [PDF-2.08MB]

Publications
In addition to the information provided here, a full listing of project related publications and presentations as well as a listing of funded students can be found in the Methane Hydrate Program Bibliography [PDF].

Rosenbaum, E.J., D.W. Shaw, R.J. Lynn, R.P. Warzinski, “Thermal conductivity and thermal diffusivity of methane hydrate using a single-sided approach,” Proceedings: 237th ACS National Meeting, Salt Lake City, UT; March, 2009.

Warzinski, R.P., I.K. Gamwo, E.J. Rosenbaum, E.M. Myshakin, H. Jiang, K.D. Jordan, N.J. English, D.W. Shaw; “Thermal Properties of Methane Hydrate by Experiment and Modeling and Impacts upon Technology,” [PDF] Proceedings: 6th International Conference on Gas Hydrates, Vancouver, Canada; July, 2008.

Rosenbaum, E.J, N.J. English, J.K. Johnson, R.P. Warzinski; “Thermal Conductivity of Methane Hydrate from Experiment and Molecular Simulation,” J. Phys. Chem. B, 112, 2007, 10207-10216.

Warzinski, R. P., R. J. Lynn, D. W. Shaw and E. J. Rosenbaum, “Thermal Property Measurements of Methane Hydrate Using a Transient Plane Source Technique,” in press, AAPG Hedberg Conference book on Gas Hydrates.

References
1. Gustafsson SE, Transient plane source techniques for thermal conductivity and thermal diffusivity measurements of solid materials. Review of Scientific Instruments, 1991; 62(3): 797 - 804.

2. Gustafsson SE, Device for measuring thermal properties of a test substance-the transient plane source (TPS) method. 1991, U.S. Patent 5,044,767 Thermetrol AB (SE): U.S. p.