A solid ice-like material resulting from the combination of a gas with water under pressure. Of natural gas constituents -- methane, ethane, propane, isobutane, normal butane, and also hydrogen sulfide and carbon dioxide will form hydrates. The greater the pressure in the equipment, the higher the temperature at which the hydrate will form, usually well above freezing. Hydrates can cause restriction or stoppage of flow, and can be controlled by alcohol injection or by dehydration of the gas. Methane hydrates are found in some permafrost regions and beneath portions of the ocean floor and may eventually be a source of methane gas.