Data Home | Math Topics | Environment Topics | Topics Matrix | Master List | Help
 Download the Data Data Set #066 About the Data View the Data Help with Using Data Play with the data on StatCrunch

Go to Top

Natural gas is an important fuel source in the United States, produced by wells drilled into rocks in the Gulf Coast states, in California, and along the continental shelf (among other locales). Natural gas consumption is currently running about 20 trillion cubic feet annually and is expected to increase another 10 Tcf over the next few decades as consumers switch from oil and electric heat to natural gas, and as new demands for natural gas crop up (such as gas fired electric generators).

Gas produced during the low demand summer months must be stored until needed, which presents a big challenge to the gas industry. Above ground storage tanks are useful and convenient on a small scale, but most natural gas is stored underground. Underground reservoirs for gas include oil fields that have been depleted of their petroleum (the extraction wells can be easily reversed and turned into injection wells) and abandoned salt mines (common in the Gulf Coast states where natural gas is produced from nearby rock formations). The current US underground storage capacity is over 3 trillion cubic feet, as can be seen from the data.

The data show the variation in cumulative natural gas storage capacity in the US (almost all underground) from 1932 to 2000. New storage capacity is added to the previous year's total to create an ever increasing series of values, though not at a constant rate. Much of today's storage capacity came online from approximately 1950-1980, as reflected in the steeper portion of the S-shaped distribution of values. The shape of the cumulative storage capacity curve reflects the variability in new storage additions with time. Students could be asked to sketch this other curve (time versus additions) based on the shape of the cumulative curve.

The student can analyze the data using a logistic model, a form of exponential growth where the rate of growth decreases linearly with increasing time (in this case). Trial and error may be appropriate to finding a well-behaved model, or the student may have a logistic regression algorithm on their technology of choice. What is the projected limit to gas storage according to the model? Logistic growth is common in many natural organisms; their size or abundance is often limited to physiology or environmental conditions (a fixed food supply). Is there really some "physical limit" to underground gas storage capacity, and if so, what might that be?

Source: American Gas Association's report, The Evolution of Underground Natural Gas Storage: Changes in Utilization Patterns, prepared by International Gas Consulting, Inc. (whose website contains a condensed version of this report).

Go to Top
View the Data

 US Cumulative underground gas storage capacity, 1932-2000 Source: International Gas Consulting, Inc. volume of natural gas in billions cubic feet (Gcf) year Gcf 1932 12 1933 12 1934 12 1935 18 1936 53 1937 88 1938 88 1939 88 1940 123 1941 187 1942 193 1943 199 1944 199 1945 216 1946 216 1947 363 1948 404 1949 474 1950 550 1951 708 1952 719 1953 854 1954 906 1955 930 1956 930 1957 994 1958 1135 1959 1205 1960 1246 1961 1328 1962 1386 1963 1561 1964 1626 1965 1678 1966 1854 1967 1860 1968 1912 1969 1930 1970 2111 1971 2175 1972 2252 1973 2398 1974 2415 1975 2538 1976 2678 1977 2725 1978 2790 1979 2795 1980 2889 1981 3023 1982 3047 1983 3047 1984 3047 1985 3047 1986 3047 1987 3053 1988 3053 1989 3064 1990 3105 1991 3123 1992 3158 1993 3246 1994 3246 1995 3292 1996 3310 1997 3310 1998 3322 1999 3380 2000 3404
Go to Top