Two industry milestones have been reported recently. In 2009, marketed production of natural gas reached 21.9 trillion cubic feet (Tcf), the highest recorded total since 1973, according to the Energy Information Administration’s latest Annual Energy Outlook 2010.

Separately, and for the first time in about a decade, more oil wells were completed in second-quarter 2010 than gas wells, according to the American Petroleum Institute.

Estimated second-quarter oil-well completions surged 59% over last year’s quarter, to 4,847 wells, versus 4,396 natural gas wells. The latter rose 22% from 2009’s second quarter.

Production from shales and tight-sand formations continues to increase, thanks to more efficient techniques for horizontal drilling and fracturing. Shale gas has been the primary source of recent growth in U.S. technically recoverable natural gas resources, said the EIA.

The gas-rig count fell to a low of 665 on July 17, 2009, marking the lowest level since 2002, before recovering to 759 by December 31.

As of July 9, 2010, the gas-directed rig count had climbed further, to 964, per Baker Hughes’ weekly tally. The gas-directed rig count is only nine rigs below the 14-month high of 973 hit on April 16, 2010, according to Reuters.

Low gas prices in the first quarter had many people expecting gas drilling to slow down this year, but it did not.

EIA’s Annual Energy Outlook 2010 includes estimates of unproved, technically recoverable, shale-gas resources of 347 Tcf, versus its 2009 estimate of 267 Tcf. Proved reserves have continued to grow over the past several years—at the end of 2008, proved reserves of dry natural gas were an estimated 245 Tcf, increasing for the 10th consecutive year.

If the increase in the U.S. rig count continues on its current path, producers will move more reserves into the proved column.

Total wells completed in the second quarter rose 38% year-over-year to 10,358 oil, gas and dry holes, according to API’s 2010 Quarterly Well Completion Report: Second Quarter. This occurred after the well completion tally had declined 22% in the first quarter relative to 2009.

“The roller-coaster year of 2009 has given way to somewhat brighter prospects in U.S. drilling activity in 2010,” said Hazem Arafa, director of API’s statistics department.

“As expectations for crude and natural gas demand have become more bullish, drilling activity has started to reverse its steep decline from the last five quarters. In 2010’s second quarter, the estimated number of exploratory oil and natural gas wells drilled jumped 35% from second-quarter 2009, demonstrating the oil and natural gas industry’s continued commitment to finding new sources of oil and gas to increase U.S. production.”

API also reported total estimated footage of 58,373,000 feet drilled in the second quarter of 2010, a 16% increase from second-quarter 2009.