Much of the natural gas supplies in the world will be found in offshore and permafrost environments such as the North Sea, the Arctic Oceans, Siberia, and the deep-water (3000 to 10,000 ft) Gulf of Mexico. The efficient exploration, production, and processing of that gas will involve high-pressure phase equilibrium data which are not currently available.
Since deep-water and permafrost temperatures are very cold, it is vital to have phase equilibria and kinetics knowledge of solids such as ice and natural gas hydrates. These crystalline solids tend to plug flow channels and produce severe hindrances to deep-water gas recovery.
We have recently discovered that there is a tremendous quantity of biogenic natural gas which has been concentrated in hydrates through decomposition of oceanic plant and animal matter. The total carbon available as conventional energy in the carbon cycle is about 5 E 15 kilograms; there is twice as much energy available from hydrated gas reserves. New technology will be required to recover it, however, because one of the primary gases encapsulated is methane (a greenhouse gas). The large natural masses of hydrate have caused environmental concern as well.
We have established a Center for Research on Hydrates and Other Solids which comprises an interdisciplinary team of about 20 persons, including Professor Christiansen of Petroleum Engineering, Professor Wada of Physics, Professors Harrison, Wendlandt, and Curtis of Geology, and Dr. Burruss and Mr. Collet of the U.S. Geological Survey.
Three areas of current interest are:
Time-dependent (Kinetic) Hydrate Studies
In this work we seek an answer to the question "How do hydrates form?" to supplement the earlier question 'What are the hydrates?" By learning how hydrates form, we are generating a new type of kinetic hydrate inhibitor which effectively prevents hydrates from growing to a crystal mass which can plug a flow channel. We have a consortium of 12 industrial companies which have funded this work for several years; these companies are currently field testing the chemicals we generate. The Gas Research Institute-and the Gas Processors Association have funded more fundamental research studies in kinetics.
Hydrate Analogs to Carbon Buckyballs
The clusters in our hydrate cavities are geometrically analogous to the carbon clusters cafled-"buckyballs' after Buckminster Fullerenes. The carbon chemistry investigations have been more extensive and demonstrate the possibility of other. as-yet-undiscovered hydrate cavities and structures. This work and the research below are funded by the National Science Foundation.
Structure H Hydrates
One of the newest hydrate structures, these compounds form using large molecules, such as components of diamondoids. gasoline, and napthalene, which move hydrates from the gas industry into the domain of concern of the petroleum industry. We measured the phase equilibria of these compounds and believe they will play a large role in future petroleum processes and separations.
