The economic production of natural gas from oceanic hydrate deposits will require new offshore drilling systems and methods. Also, the product of hydrate dissocia­tion may be relatively low pressure, wet gas, especially where the excess pressure produced by hydrate dissociation can be equilibrated rapidly through high-porosity sediments. Natural gas derived from hydrate may result in […]

If commercial production from oceanic natural gas hydrates is eventually estab­lished, there are at least three ways to transport the gas ashore: (1) by conventional pipeline; (2) by converting the gas hydrates to liquid middle distillates via the newly improved Fischer-Tropsch process and loading them onto a conventional tanker or barge; or (3) by reconverting […]

The main cost here is only that of the pipeline used to transport the gas to the pro­duction platform. For subsea systems that do not produce to a fixed platform, a drilling template must be used that connects to a group of wells. Drilling capabilities developed for conventional deepwater hydrocarbon explo­ration and production are presently […]

Subsurface occurrences of natural gas hydrate can be classified into six types: (1) pore-space hydrate, (2) platy hydrate, (3) layered/massive hydrate, (4) dissemi­nated hydrate, (5) nodule hydrate, and (6) vein/dyke hydrate. The anomalies of chloride contents in pore water, core temperature depression, core observation, as well as visible gas hydrates confirmed well-interconnected and highly saturated […]

Gas hydrates are found within and beneath permafrost on the North Slope of Alaska, in the Canadian Arctic, and in northern Siberia. The Arctic hydrates have the potential to become economically viable sources of natural gas. The best do­cumented Alaskan accumulations are in the Prudhoe Bay-Kuparuk River area, which contains approximately 30 trillion standard cubic […]

There are two gas hydrate reservoirs. They are Arctic hydrates and marine hy­drates. Gas hydrates are found within and under permafrost in Arctic regions. They are also found within a few hundred meters of the seafloor on continental slopes and in deep seas and lakes. The reservoir architecture, technology needs, and eventual economic importance of […]

The third method is chemical inhibition, a concept similar to the chemical means presently used to inhibit the formation of water ice. This method seeks to displace the natural gas hydrate equilibrium condition beyond the hydrate stability zone’s thermodynamic conditions through injection of a liquid inhibitor chemical adja­cent to the hydrate. The chemical inhibitor injection […]

The second method is thermal stimulation, in which a source of heat provided directly in the form of injected steam or hot water or another heated liquid, or indirectly via electric or sonic means, is applied to the hydrate stability zone to raise its temperature, causing the hydrate to decompose. In the thermal stimulation process, […]