NETL-ORD4

NETL ORD – Methane Hydrate Research - Thermal Properties of Hydrate – Tool Development

Last Reviewed 6/22/2011

Project Goal

The goal of this project is to provide high-quality information on gas hydrate thermal properties, which are among the important parameters for understanding the behavior of natural gas hydrates. Understanding these parameters will benefit the development of models and methods for predicting the behavior of gas hydrates in their natural environment for gas production or climate change scenarios. This project provides a means to measure the thermal properties of natural hydrate-bearing sediment cores, and hydrate-bearing cores formed inside 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

Project Description

The experiment system was designed to be mobile and adaptable for multiple scenarios. The technique can 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 that is suitable for use in other research facilities and, with some adaptations, a device that can be used in the field. To more accurately determine the thermal diffusivity, a time dependent value, a numeric approach was developed and extensively tested with experimental data.

The thermal properties device is being incorporated in reactors designed for CT scanning. X-ray CT scans provide information on the porosity and composition of the sample being measured. The best approach for determining the thermal properties of natural samples is to take measurements on undisturbed cores. Pressure cores that have been transferred to a properly pressurized vessel will provide the best means to measure thermal properties of natural samples.

Background

Measurement Technique
NETL utilizes a modified transient plane source (TPS) shown in Fig. 1 in a technique originally developed by Gustafsson [1, 2], in a single-sided configuration (Fig. 2). The TPS technique provides simultaneous determination of the thermal conductivity and thermal diffusivity. During the measurements, the TPS serves as a heat source and temperature sensing element. 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 adhered to PVC which provides support for the sensor, especially during compaction experiments and also allowed for development to progress to an in-situ probe. This single-sided approach does not require large samples and it enables measurements to be made by 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).

Facilities and Equipment
Figure 3 shows one of the NETL experimental setups. The TPS for this type of experiment is part of an integrated container called the High-Pressure Thermal Properties Measurement Device (HTMD) that allows sample formation to occur directly on the sensor and subsequent sample consolidation, all in the same container under pressure. The HTMD consists of a sample cup containing the TPS sensor, an internal piston for controlling gas volume and for performing sample compaction, and pressure (digital Heise gauge, ± 0.02 %) and temperature (platinum RTD, ± 0.3°C) sensors. The HTMD is housed in an explosion resistant, programmable environmental chamber to provide temperature control (243 K to 343 K within 0.1 K) during experiments. Measurements are made on the sample during formation and throughout the experiment. Since the sample is formed in the container where measurements are made, sample integrity is better preserved. A picture of compacted methane hydrate formed in the HTMD and recovered in liquid nitrogen is shown at the bottom of Fig. 3.

Figure 3. The NETL high-pressure thermal property measurement system.
A sample of compacted methane hydrate formed in the HTMD is also shown.

Current Status
Thermal property measurements have been made on pure methane hydrate and methane hydrate in sediments that have been formed in the laboratory. NETL has developed a technique capable of implementation into almost any device. NETL researchers are in pursuit of collaborations with other groups to incorporate this technique into existing devices for measurements on preserved hydrate-bearing sediments.

Project Funding:
FY05: $160,000
FY06: $264,000
FY07: $190,600
FY08: $212,900
FY09: $129,900
FY10: ~$49,000

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.

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