Table 19.-Natural gas: Production, by country—Continued 1 In addition to the countries listed, Albania, People's Republic of China, Cuba, East Germany, Malaysia (Sarawak), Mongolia, Spain, Syrian Arab Republic, Thailand, and Turkey, produce crude oil and presumably produce natural gas, but available information is inadequate to ascertain output levels and the share of gross production that is marketed. Of these countries, only People's Republic of China is regarded as being a significant gas producer. 2 Comprises all marketed production (see footnote 3) plus gas vented, flared, reinjected for repressuring and used to drive turbines (without being burned). Comprises all gas collected and utilized as fuel or as a chemical industry raw material, including gas used in oil and/or gasfields as a fuel by producers even though the latter is not actually sold. Gross production not reported, marketed output has been reported in lieu of a gross production estimate because the quantity flared, vented and reinjected is believed to be small. Marketed production reported includes gas produced from coal mines as follows in million cubic feet: Czechoslovakia: 1969-10,064, 1970-11,442, 1971- 11,654; Poland: 1969-9, 1970-not available, 1971not available. Available statistics used for both gross and marketed output comprise marketable production plus gas used for repressuring, but excludes gas vented and/or flared; reportedly gas used for repressuring constituted only 0.4 percent of the 1968 total shown. Information is inadequate to make a reliable estimate of gas vented or flared but it is believed to be small if any. 7 Marketed production reported includes gas produced from coal and oil shale as follows in million cubic feet: 1969-61; 1970-not available; 1971-not available. 8 No marketed production reported; there may be some small field use, but available information is inadequate to make reliable estimates. Includes gas reinjected, if any. 10 Data for both Kuwait and Saudi Arabia each include 1⁄2 of the total output recorded for the former KuwaitSaudi Arabia Neutral Zone. Reported sales; presumably excludes fuel use in fields and pipeline system. Natural Gas Liquids By S. O. Wood, Jr.1 and Leonard L. Fanelli 2 Production of natural gas liquids from gas-processing plants increased to a new high of 617.8 million barrels, 12 million barrels above 1970 output. The value of 1971 output was $1,386 million, $111 million or 8.7 percent higher than that of 1970. Natural gas liquids are products obtained from the processing of natural gas at natural gasoline plants, cycling plants, and fractionators. Included are ethane, the liquefied petroleum (LP) gases (butane, propane, and butane-propane mixtures), isobutane, mixed gases, natural gasoline, plant condensate, and finished products including gasoline, special naphthas, jet fuel, kerosine, distillate fuel oil, and miscellaneous finished products. Continued demand for petrochemical feedstock along with increased producing capacity contributed to the 7.1-millionbarrel, 9.7-percent, increase in ethane production. The largest volume increase, however, was in propane production, 9.6 million barrels. Isopentane production increased 1.7 million barrels, a rate increase of 44.0 percent. Plant condensate production declined 6.2 million barrels, a decrease of 19.0 per cent. Increased production coupled with a continued low level of industrial activity and a mild winter resulted in propane stocks attaining a record high of 63.3 million barrels in October 1971. Total LP gases stocks at that time were 93.4 million barrels, compared with 1970 stocks of 70.6 million barrels. The average unit value for natural gas liquids production was $2.24 per barrel, a 6.7-percent increase from the comparable 1970 value. Unit value changes by groups from 1970 to 1971 were as follows: LP gases and ethane, up 9.5 percent to $1.84 per barrel, natural gasoline and isopentane, up 5.6 percent to $3.00 per barrel; plant condensate, up 6.0 percent to $3.37 per barrel; finished gasoline and naphthas, up 7.2 per cent to $4.34 per barrel, and other products, down 4.0 percent to $2.62 per barrel. Data presented in this chapter were compiled from operating reports of natural gasoline plants, cycling plants, and fractionators that process natural gas and include all natural gas liquids except the small volume, considered to be insignificant in the national and State totals, recovered at pipeline compressor stations and gas dehydration plants. Plant condensate is included in natural gas liquids; field separated condensate, however, is included with crude oil. Ethane and liquefied gases such as butane and propane, recovered from the crude oil refining operations are classed as liquefied refinery gases (LRG) and reported as refinery products. Annual reports were received from all large producers and distributors and from most of the dealers that sell more than 100,000 gallons of LP gases per year. To reflect total shipments, the sample of dealer shipments was expanded by Petroleum Administration for Defense (PAD) districts on the basis of domestic demand in the districts. Components of natural gas liquids used in this chapter are defined as follows: Ethane. Includes ethane only. All other LP gases mixed with ethane are reported in their respective product classification. Propane. Includes all products covered by the Natural Gas Processors Association (NGPA) specifications for commercial and HD-5 propane. Butane-Propane Mix.-Includes all products covered by NGPA specifications for commercial butane-propane mixtures. Butane. Includes all products covered by NGPA specifications for commercial butane, except those that contain 80 percent or more isobutane. 1 Petroleum engineer, Division of Fossil Fuels. 2 Survey statistician, Division of Fossil Fuels. Isobutane. Includes all products covered by NGPA specifications for commercial butane, which contains 80 percent or more isobutane. Isopentane. Includes segregated isopen tane. Natural Gasoline.-A hydrocarbon mixture used primarily for blending or further processing into finished gasoline. Plant Condensate.-Includes those liquids, mostly pentanes and heavier, recovered and separated at raw natural gas inlet separators and scrubbers. Gasoline. Includes all products within the gasoline range for shipments as motor fuel. Special Naphtha.-Includes all hexanes and heptanes. Jet Fuel.-Includes all aviation turbine engine fuel for both military (JP-4 and JP-5) and commercial use. Kerosine. Includes all grades of kerosine or range oil. Distillate Fuel Oil.-Includes all light oil for shipment as fuel, including diesel fuel oil. Other Products.-All products not otherwise classified. Production of natural gas liquids is reported by States, however production for Louisiana and Texas is also reported by districts. Louisiana is divided into an Inland district and a Gulf Coast district. The Gulf Coast district includes Vernon, Rapides, Avoyelles, Pointe Coupee, West Feliciana, East Feliciana, Tangipahoa, St. Helena, and Washington Parishes and all parishes in the State south of these. All parishes not inIcluded in the Gulf Coast district are in the Inland district. The Bureau of Mines producing districts in Texas correspond, with one exception, to groupings of Texas Railroad Commission districts: 1.-East Coast-District of Coumbia, Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, the following counties of New York: Cayuga, Tompkins, Chemung, and all counties east and north thereof, and the following counties of Pennsylvania: Bradford, Sullivan, Columbia, Montour, Northumberland, Dauphin, York and all counties east thereof. 1.—Appalachian No. 1-West Virginia and those parts of Pennsylvania and New York not included in the East Coast district. 2.-Appalachian No. 2-The following counties of Ohio: Erie, Huron, Crawford, Marion, Delaware, Franklin, Pickaway, Ross, Pike, Scioto, and all counties east thereof. 2.-Indiana-Illinois-Kentucky - Indiana, Illinois, Kentucky, Tennessee, Michigan, and that part of Ohio not included in the Appalachian district. 2.-Oklahoma-Kansas, Missouri Oklahoma, Kansas, Missouri, Nebraska, and Iowa. Minnesota-Wisconsin-North 2. DakotaSouth Dakota-Minnesota, Wisconsin, North Dakota, and South Dakota. 3.-Texas Inland-Texas, except Texas Gulf Coast district. 3.-Texas Gulf Coast-The following counties of Texas: Newton, Orange, Jefferson, Jasper, Tyler, Hardin, Liberty, Chambers, Polk, San Jacinto, Montgomery, Galveston, Waller, Fort Bend, Brazoria, Wharton, Harris, Matagorda, Jackson, Victoria, Calhoun, Refugio, Aransas, San Patricio, Nueces, Kleberg, Kenedy, Willacy, and Cameron. 3.-Louisiana Gulf Coast-The following parishes of Louisiana: Vernon, Rapides, Avoyelles, Pointe Coupee, West Feliciana, East Feliciana, Tangipahoa, St. Helena, Washington, and all parishes south thereof; the following counties of Mississippi: Pearl River, Stone, George Hancock, Harrison, and Jackson; and in Alabama: Mobile and Baldwin Counties. Figure 2.-The relative production of natural gas liquids, 1971. propane, 62.9; normal butane, 17.2; isobutane, 9.6; butane-propane mix, 1.2; and other butanes, 9.1. Natural gasoline and isopentane production was 165.3 million barrels, virtually un changed from 1970, and accounted for 26.8 percent of natural gas liquids output. Ethane production, 80.5 million barrels, amounted to 13.0 percent of the natural gas liquids. RESERVES The American Gas Association, Inc. (AGA), Reserves Committee estimated proved reserves of natural gas liquids at yearend 1971 to be 7,304 million barrels. Proved reserves declined for the fourth consecutive year. According to AGA data, the yearend reserve to 1971 production ratio was 9.8:1, compared with 13.4:1 in 1967. Reserve additions from the discovery of new fields and new reservoirs totaled 119 million barrels of which 90 million barrels were in South Louisiana, principally offshore. Texas accounted for 42 percent, and Louisiana accounted for 34 percent of the Nation's proved natural gas liquids reserves at year |