The Philadelphia Inquirer has an article on green completions that you may be interested in: "The towering flares that turn night into day in the Marcellus Shale gaslands are becoming an increasingly rare sight. Natural gas producers are turning to new techniques to capture the gas emitted during the well-completion process. In the past, a well's initial production was typically vented or burned off to allow impurities to clear before the well was tied into a pipeline."