back to - Gary S. Swindell, Petroleum Engineering

2005 Texas Gas Well Study Summary

Click here for the SPE 70018 paper graphs and text - "Changes in the Performance of Texas Gas Wells"

Click here for the original 1999 Oil & Gas Journal article

Year of First Production  New Gas Well Connections   Wells still Active 2-99   Maximum Production Rate - MCF/month  First year Decline Rate - % Overall 5 year Decline Rate - %  Projected Ultimate Recovery - MMCF/Well  10 Yr Survival Rate %  Annual Prod - Gas Wells MMCF   Annual Prod - All Wells MMCF   From brand new wells   Annual Gas fm Existing  % of gas fm new gas wells  New Oil & Gas Compl (RRC)   New Gas Compl (RRC)  5th yr d1 10th yr d1 10 yr wells  Annual Prod - Oil Wells BCF 
1971               1,934                204                  52,324 10 10                6,245 31%       7,267,069       9,414,963         506,095   8,908,868 7.0%            7,737 11 11 600   2,147,894
1973               2,657                543                  38,675 22 19                3,671 38%       7,200,071       9,196,535         522,471   8,674,064 7.3%            8,656 8 8 1000   1,996,464
1976               4,289                901                  23,329 19 15                2,567 35%       6,217,431       7,675,088         523,081   7,152,007 8.4%          12,982 10 6 1490   1,457,657
1978               5,217             1,310                  18,871 14 16                2,463 39%       5,643,849       7,029,862         486,306   6,543,556 8.6%          15,863 20 2 2040   1,386,013
1980               5,310             1,462                  18,213 24 19                1,697 41%       5,686,583       7,009,876         498,837   6,511,039 8.8%          20,038 13 6 2200   1,323,293
1981               5,687             1,667                  17,772 31 16                1,842 40%       5,379,173       6,736,439         493,663   6,242,776 9.2%          26,442 7 6 2300   1,357,266
1982               6,034             1,870                  15,589 30 14                1,713 41%       4,719,622       6,107,572         466,705   5,640,867 9.9%          25,439 9 10 2500   1,387,950
1983               4,828             1,285                  15,601 12 10                1,967 36%       4,234,354       5,649,601         368,275   5,281,326 8.7%          24,089 8 7 1720   1,415,247
1984               5,627             1,650                  16,652 24 14                1,727 37%       4,387,003       5,875,646         432,612   5,443,034 9.9%          27,696 12 10 2100   1,488,643
1985               4,944             1,505                  21,082 26 18                1,717 38%       4,326,918       5,821,436         490,977   5,330,459 11.3%          24,921 15 10 1900   1,494,518
1986               3,024                962                  19,180 24 16                1,686 40%       4,234,396       5,677,514         320,729   5,356,785 7.6%          13,253 12 10 1200   1,443,118
1987               3,050                990                  21,423 34 19                1,463 38%       4,165,905       5,544,145         315,946   5,228,199 7.6%          11,259 10 6 1150   1,378,240
1988               3,321             1,179                  21,192 26 19                1,630 39%       4,342,480       5,714,180         357,036   5,357,144 8.2%            9,978 15 8 1310   1,371,700
1989               3,389             1,369                  26,416 22 13                2,309 42%       4,282,988       5,605,992         370,229   5,235,763 8.6%            8,503 10 1420   1,323,004
1990               3,372             1,563                  22,123 26 23                1,568 46%       4,257,407       5,553,177         388,018   5,165,159 9.1%            9,014 15 1559   1,295,770
1991               2,979             1,514                  24,917 32 24                1,470 48%       4,226,860       5,536,911         370,936   5,165,975 8.8%            9,053 14 1420   1,310,051
1992               3,165             1,795                  27,820 41 25                1,398 54%       4,146,527       5,467,163         371,919   5,095,244 9.0%            7,596 16 1697   1,320,636
1993               3,860             2,305                  31,127 44 26                1,358 54%       4,335,720       5,645,452         577,094   5,068,358 13.3%            8,460 17 2080   1,309,732
1994               4,431             2,792                  29,882 42 28                1,483 55%       4,492,443       5,711,491         651,222   5,060,269 14.5%            8,055 18 2443   1,219,048
1995               3,883             2,663                  33,170 45                   30                1,382 55%       4,569,900       5,713,023         603,289   5,109,734 13.2%            8,195 2145   1,143,122
1996               4,267             3,131                  39,591 55                   33                1,468       4,770,283       5,868,664         732,617   5,136,047 15.4%            8,729            4,060   1,098,381
1997               4,700             3,734                  35,243 53                   31                1,355       4,819,101       5,854,393         723,512   5,130,881 15.0%            9,076            4,594   1,035,292
1998               4,384             4,075 40999 56                   32                1,425       4,850,384       5,833,474         822,601   5,010,873 17.0%            9,416            4,907      983,090
1999               3,558 43671 51                   34                1,453       4,776,374       5,665,144         681,534   4,983,610 14.3%            5,615            3,566      888,770
2000               4,467 44894 60                   34                1,491       4,881,900       5,756,448         852,301   4,904,148 17.5%            7,691            4,580      874,548
2001               5,629 38743 63                   35                1,207       4,961,971       5,817,318         934,974   4,882,343 18.8%            8,869            5,787      855,346
2002               4,819 41521 62                1,261       4,885,008       5,719,048         856,745   4,862,303 17.5%            8,742            5,474      834,039
2003               5,958 36510 63                1,187       4,978,993       5,816,130         923,501   4,892,629 18.5%            9,447            6,336      837,137
2004               6,879 32355 60                1,039       5,109,751       6,037,275         958,052   5,079,223 18.7%          10,564            7,118      927,524
2005               5,632 32059 61                1,033       5,216,755       5,905,623         913,877   4,991,746 17.5%          10,651            7,197      688,868
Total             97,910
           8,729
           9,874