30 Kasım 2012 Cuma

MIT Blockbuster Study Finds Shale Gas Methane Emissions Greatly Exaggerated: Shale Gas Is Cleaner Than Even EPA Number

To contact us Click HERE
Yesterday researchers from MIT published a peer reviewed, blockbuster study that finds that Prof. Howarth of Cornell University greatly exaggerated the methane emissions coming from shale gas wells. Indeed, the MIT data indicate that Howarth's now infamous study overstated methane emissions to the atmosphere by a range of 7 to 30 times the actual release from the nearly 4,000 shale gas wells that the MIT study analyzed.
web.mit.edu/newsoffice/2012/fugitive-methane-from-shale-less-than-thought.html. And this is the MIT study:
iopscience.iop.org/1748-9326/7/4/044030/pdf/1748-9326_7_4_044030.pdf.

The MIT paper notes that Prof. Howarth looked at a handful of shale gas wells; then overstated the potential release of gas from that handful of wells; and further totally falsely assumed that all shale gas wells vented 100% of the full gas potential release.  In other words, Howarth miscalculated how much each gas well could release, even if all gas was vented during the flowback period.  And then Howarth falsely assumed that no shale gas well is green completed or flared but all gas is vented.

The MIT researchers politely said of Howarth's assumption that it is "unreasonable."  Of course, the venting assumption was far from the only "unreasonable" assumption in the Howarth paper.

By contrast, MIT looked at 4,000 shale gas wells, and not just a handful, to get a more accurate estimate of what each gas well could potentially release to the atmosphere, were it vented. MIT then looked at actual industry practices for venting, flaring, and green completions at shale wells.  Francis O'Sullivan and Sergey Paltsev, the two MIT researchers conducting the study, calculated that 70% of shale gas wells are green completed; 15% are flared; and 15% are vented.

The bottom line of the MIT researchers paper is that the "carbon footprint" of a shale gas well has been greatly exaggerated and is even lower than the EPA 2011 estimate.

The MIT study also looks at the cost of green completing a Barnett shale gas well and compares those costs to the revenues gained by paying for a green completion.  The paper finds that 95% of the time the green completions paid for themselves and would still pay for themselves 83% of the time if the costs of completion were doubled.  This cost data indicates that companies in most cases would be losing money by not green completing a shale gas well.

Climate change is an enormous challenge that demands honest, disciplined science. Even the passions stirred by the fracking debates should not allow the real science and facts of methane emissions from shale gas wells to be manipulated and demagogued. The facts are and science shows that shale gas has reduced substantially US carbon emissions and could be doing the same globally because it is cleaner than coal or oil.  Telling good people the opposite is irresponsible!

Hiç yorum yok:

Yorum Gönder