The fracking revolution gets better, and oil wells produce more.
When it started, fracking was somewhat a hit and miss, trial by error effort to learn how to extract oil and natural gas from shale.
Horizontal wells were initially fairly short, perhaps a few thousand feet long, and only single fracs were used.
As more was learned, horizontal wells became longer and there were more fracs on each well. Multiple fracs are done by separating the horizontal well, or lateral, into shorter sections, beginning at the far end of the lateral, by blocking off each section, and performing the frac operation in each section, one at a time.
Today, horizontal wells, or laterals, can be 10,000 feet long, or nearly two miles long, with thirty fracs taking place in a lateral.
The length and depth of wells vary with each shale formation, but the trend is similar in virtually all areas, longer horizontal wells and more fracs.
Here are a few comparisons:
- Eagle Ford, average horizontal length approximately 6,500 feet, longest 10,000 feet. Deepest vertical, approximately 8,000 feet.
- Permian Basin (all), average horizontal length approximately 7,500 feet, longest 9,500 feet. Deepest vertical, approximately 11,500 feet.
- Bakken, average horizontal length approximately 9,500 feet, longest 9,900 feet. Deepest vertical, approximately 11,500 feet.
- Marcellus, average horizontal length approximately 4,500 feet, longest 7,000 feet. Deepest vertical, approximately 9,000 feet.
In nearly all cases, the amount of oil or natural gas being produced has increased significantly.
As can be seen, fracking typically takes place several thousand feet below the water table, so there is little, if any possibility that fracking can contaminate aquifers or water wells.
One of the trends that has emerged is that the gravity API rating of the oil has become higher, which means the oil has become thinner.
Crude oil used by refineries has an average API of around 34, ranging from 30.07 to 37.27 in different districts this year. Oil that is considerably thinner, with a higher API rating, is less valuable. Oil with an API of 50, might have a value $5 less per barrel than crudes with an API of 34. Condensate, which is even thinner, may be worth $10 less per barrel than oil with an API of 34.
Interestingly, Bakken crude consistently has an API of around 42, which appears to be acceptable to many refineries, those that aren’t designed to process heavier crudes.
The latest study on well contamination, published by the Proceedings of the National Academy of Sciences, Noble gases identify the mechanisms of fugitive gas contamination in drinking-water wells overlying the Marcellus and Barnett Shales, once again demonstrated that fracking does not cause contamination of water wells or aquifers.
The study specifically stated that methane, i.e., natural gas, did not migrate through multiple strata of rock above where the fracking took place, to reach water wells or aquifers.
Contamination by methane can result from poor cementing of wells, but this can be for any kind of drilling. It’s also a preventable problem.
The myth that fracking caused methane contamination was perpetuated by the movie Gas Land which showed a water faucet being set on fire.
This picture, published in the National Geographic Magazine decades before fracking became popular, and decades before the movie Gas Land, clearly demonstrates that methane can migrate naturally into water wells.
New practices are increasing the amount of oil being produced from fracking, bringing the United States ever closer to being independent of foreign crude, other than from Canada and Mexico.
Fracking has been a blessing for the United States, resulting in greater oil production, low cost natural gas for power generation and the heating of homes, increased jobs, bringing manufacturing back to the United States and improving our balance of payments.
The new practices include more fracs in each horizontal well, longer horizontals and the use of greater quantities of sand to prop open the cracks in the shale created by the fracking process.
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