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Gas Hydrates Project Physical Properties Laboratory

An important aspect of gas hydrate studies is understanding the properties of the reservoirs that host hydrate deposits. The USGS Gas Hydrates Project analyzes the sediments that make up gas hydrate reservoirs in the Physical Properties Laboratory. 

The physical, geotechnical, and geophysical properties of sediments can determine how much hydrate forms in the reservoir, where the hydrate forms with respect to sediment pores, whether gas migrates through sediments or becomes trapped, and whether reactions between sediment grains and pore waters affect the thermodynamic stability of gas hydrates.

The most important analyses conducted in the Physical Properties Lab provide index property data on grain size distribution in sediments, bulk and grain density, and liquid/plastic limits.  For these analyses, researchers often use the sediment left behind after hydrate recovered in pressure cores breaks down.  To make these measurements, researchers use a variety of grain size analysis techniques, a drying oven, a 5-cell pycnometer, an optical microscope, and benchtop methods.  Because different sediment types (e.g., clay vs. sand) can produce different gas hydrate nucleation and growth patterns, researchers also measure specific surface and use X-ray diffraction data to discern the composition of sediment grains.

A man wearing a mask using laboratory equipment
Grain density results obtained using a pycnometer inform other geotechnical testing, such as the consolidation results from the laboratory’s oedometers.