Direct experiments on the ocean disposal of fossil fuel CO2

Field experiments were conducted to test ideas for fossil fuel carbon dioxide ocean disposal as a solid hydrate at depths ranging from 349 to 3627 meters and from 8 degrees to 1.6 degrees C. Hydrate formed instantly from the gas phase at 349 meters but then decomposed rapidly in ambient seawater. At 3627 meters, the seawater-carbon dioxide interface rose rapidly because of massive hydrate formation, forcing spillover of the liquid carbon dioxide from the container. A strong barrier between the liquid carbon dioxide and interaction with the sediments was observed. A pool of liquid carbon dioxide on the sea floor would expand in volume more than four times, forming hydrate, which will dissolve.

Hydrocarbon Drainage along Corners of Noncircular Capillaries

An approximate solution for liquid flow along corners of noncircular capillaries is proposed that relates the flow resistance to the geometry of a capillary and to the contact angle of the interfaces. The theory predicts liquid flow rates for both two-phase (hydrocarbon/air) and three-phase (hydrocarbon/air/water) drainage. This solution is found to be superior to other expressions in the literature. Drainage rates of two different hydrocarbons along corners of square capillaries are measured with both air and water as stationary phases. The new solution was used to predict the measured hydrocarbon drainage rates successfully. Comparison of the measured and predicted drainage rates indicates that a free boundary is appropriate for the air/hydrocarbon interface and a no-flow boundary condition is valid for the water/hydrocarbon interface. The effect of spreading coefficient on drainage rates is also demonstrated by the measurements and is compared with the proposed solution. A brief discussion of three-phase relative permeabilities is offered based on the measured drainage rates and proposed solution.