05.07.2009

The used up oil or gas reservoirs that are used most often to store natural gas and comprise the majority of storage.

Resources that have been extracted, including resources that have been recovered, resources that have been lost and resources that have been reclassified as un-economic to produce

Formations that have already been tapped of all their recoverable natural gas and which leaves an underground formation, geologically capable of holding natural gas. Using an already developed reservoir for storage purposes allows the use of the extraction and distribution equipment left over from when the field was productive. Of the three types of underground storage, depleted reservoirs, on average, are the cheapest and easiest to develop, operate, and maintain. The factors that determine whether or not a depleted reservoir will make a suitable storage facility are both geographic and geologic. Geographically, depleted reservoirs must be relatively close to consuming regions. They must also be close to transportation infrastructure. Geologically, depleted reservoir formations must have high permeability and porosity. The porosity of the formation determines the amount of natural gas that it may hold, while its permeability determines the rate at which natural gas flows through the formation, which in turn determines the rate of injection and withdrawal of working gas. In order to maintain pressure in depleted reservoirs, about 30-50 percent of the natural gas in the original formation must be kept as cushion gas.

Such as in the installation was drained of gas; deplete the natural gas field; exhaust the natural gas field

The departure terminal is the start of the pipeline. It contains gas storage and valve facilities, including scraper launch and outlet flowmeter systems, to send the material (oil/gas) through the pipeline system.

A log for open-hole surveying that responds to variations in the specific gravity of formations. It works as a contact log in that the logging tool is held against the wall of the hole

The mass or weight of a substance per unit volume. For instance, the density of a drilling mud may be 10 pounds per gallon. Specific gravity, relative density, and API gravity are other units of density. The weight of crude oil, indicating the proportion of large, carbon-rich molecules, generally measured in kilograms per cubic meter (kg/m3) or degrees on the American Petroleum Institute (API) gravity scale