Section 5. Crude oil and natural gas resource development

Monthly Energy Review, March, 2005

The February 2005 rotary rig count was 1,276, 2 percent higher than the count in January 2005 and 14 percent higher than the count in February 2004. Of the total number of rigs in operation, 1,170 were onshore and 106 were offshore. For February 2005, the number of onshore rigs was up 15 percent and the number of offshore rigs was up 7 percent from the February 2004 count. Rotary rigs drilling for natural gas as a share of total rigs stood at 85 percent in February 2005.

Total footage drilled in February 2005 was 18.2 million feet, 2 percent higher than the footage drilled in January 2005 and up 35 percent from that drilled in February 2004.

The number of exploratory and development crude oil and natural gas wells drilled during February 2005 was 2,763, 2 percent higher than the number drilled in January 2005 and up 16 percent from the number drilled in February 2004. The number of crude oil wells drilled was 671, and the number of natural gas wells was 2,092, 25 percent higher and 13 percent higher, respectively, than their February 2004 levels.

The number of dry holes drilled in February 2005 was 395, up 3 percent from the number drilled in January 2005 and up 15 percent from the number drilled in February 2004.

There were 2.1 thousand well service rigs active in February 2005, 3 percent higher than the previous month and 5 percent higher than the count a year ago.

The number of seismic crews active in the 48 States onshore in December 2004 was 41, 9 more than a year earlier. The number of crews active in the 48 States offshore was 7, 3 fewer than a year earlier. Two crews were active in Alaska in December 2004, 2 more than a year earlier.

Crude Oil and Natural Gas Resource Development

Table 5.2 Notes

Three well types are considered in the Monthly Energy Review (MER) drilling statistics: "completed for crude oil," "completed for natural gas," and "dry hole." Wells that productively encounter both crude oil and natural gas are categorized as "completed for crude oil." Both development wells and exploratory wells (new field wildcats, new pool tests, and extension tests) are included in the statistics. All other classes of wells drilled in connection with the search for producible hydrocarbons are excluded.

Prior to the March 1985 MER, drilling statistics consisted of completion data for the above types and classes of wells as reported to the American Petroleum Institute (API) during a given month. Due to time lags between the date of well completion and the date of completion reporting to the API, as-reported well completions proved to be an inaccurate indicator of drilling activity. During 1982, for example, as-reported well completions rose, while the number of actual completions fell. Consequently, the drilling statistics published since the March 1985 MER are Energy Information Administration (EIA) estimates produced by statistically imputing well counts and footage based on the partial data available from the API. These estimates are subject to continuous revision as new data, some of which pertain to earlier months and years, become available. Additional information about the EIA estimation methodology may be found in "Estimating Well Completions," the feature article published in the March 1985 MER.

Users of the well completion and footage figures published by the Energy Information Administration (EIA) prior to August 1998 should be aware that these data have been revised. The published well completion and footage figures are produced by the Well Completion Estimation Procedure (WELCOM) based on drilling records provided under contract to the EIA. Problems in the files received by EIA necessitated revision of the historical series for well completions and footage drilled. Queries regarding this matter may be directed to William Trapmann (202-586-6408 or william.trapmann@eia.doe.gov).