One of the reasons water contamination caused by oil and gas drilling is poorly understood is that well design and construction is extremely complex. Oil and gas well engineering is intricate, and the function is different from the machinery most of us are familiar with. This is why the oil and gas industry gets away with the great lie, “There is no known case of fracking causing water contamination.”
There are several ways oil and gas drilling causes water contamination. The most common causes are spills and improper disposal at the surface, and leakage caused by faulty cement casings at the wellbore.
Dr. Anthony Ingraffea, a professor of civil and environmental engineering at Cornell University, is one of the foremost experts on the fracking process. He has formed the Cornell Fracture Group, which creates, verifies and validates computational simulation systems for fracture control in engineered systems.
He is also a great teacher. He explains complex engineering processes like fracking in a way that is accessible to anyone. I’ll post videos of some of his lectures in the near future.
A clear comparison
He recently posted what I think is a very clear explanation of why oil and gas wells leak, and why this is inherent in their design. You don’t have to be an engineer to read the article. It is clear, concise and informative.
He accomplishes this by comparing the functioning of a wellbore (the hole drilled through the rock layers), casing (steel pipe), and cement (supposedly used as a gasket between all casing layers and the wellbore) to something that most of us are much more familiar with: the cylinder, piston, and piston rings of a car engine.
I recommend you read the article, but I’ve adapted the comparison to the chart below:
Adapted from Anthony Ingraffea, Why a car’s engine has more integrity than a shale gas well
Ingraffea’s summary makes the differences clear:
Car engine manufacturers are able to create engines with an outstanding record of integrity, whereas the manufacturers of shale gas wells, due to their casement integrity design and execution failures, should be issuing recall notices.