Offshore drilling has been happening in places like the North Sea and Gulf of Mexico for the best part of half a century. In the last decade or so drilling has pushed out into deeper and deeper water as production from shallower waters have declined, and energy prices have risen.
Where once drilling was confined to water not much more than a thousand feet deep, in recent years this has risen to almost 10,000 feet (about 2 miles) of water. Now a major push is under way to start drilling in waters deeper than 10,000 feet.
The dangers associated with offshore drilling are high, both for workers and the environment.
These dangers mount quickly as the drilling moves out into more extreme environments, into deeper waters. Deeper water means larger waves and greater difficulty anchoring things securely. This was amply demonstrated by the BP Deepwater Horizon disaster, when a well blowout at 5,000 feet, with water gushing over 5 million barrels of oil during 87 days, until it was finally capped. A similar blowout in over 10,000 feet of water would probably be unfixable.
What is Deep Water Fracking?
On land, fracking involves the process of first digging a vertical oil well. Once the vertical shaft is created, horizontal shoots are constructed to begin the process of finding the oil that is embedded within the neighboring rocks. Upon the creation of the horizontal shafts or tunnels, highly pressurized fracking fluid are injected into the rock/shale. Through the latter process, the rocks are cracked open, which allows the oil and gas to flow more freely into the wells.
Deep water fracking involves drilling an oil well at depths greater than 1,000 feet.
Offshore fracking uses a similar process to onshore fracking, in that it pumps hundreds of thousands of gallons of water, sand, and chemical mixtures into constructed tunnels within the ocean rock formations. The aim of offshore fracking is simple: get all of the possible oil out of various rock formations, while avoiding loose sand, with as minimal environmental impact as possible.
So how does it work?
Cracking rocks underground to allow oil and gas to flow more freely into wells, and has grown into one of the most lucrative oil industry practices of the past century. The technique is also widely condemned as a source of groundwater contamination.
Offshore fracking is a part of a broader industry wide strategy to make billion-dollar deep-sea developments pay off. The practice has been around for two decades, yet only in the past few years have advances in technology and vast offshore discoveries combined to make large scale fracking feasible.
In the Gulf of Mexico, water flowing back from fracked wells is cleaned up on large platforms near the well by filtering out oil and other contaminants. The treated wastewater is then dumped overboard into the vast expanse of the Gulf of Mexico, where dilution renders it harmless, according to companies and regulators.
A treatment process is regulated by the Environmental Protection Agency, but in California, where producers are fracking offshore in existing fields, critics led by the Environmental Defense Center have asked federal regulators to ban the practice off the West Coast until more is known about its effects.
Another expert said that one of the key problems, is that nobody has really looked at the environmental impacts of offshore fracking, and we find that incredibly concerning. “Nobody really knows what they’ve been discharging and in what amounts.”
A spokesperson for the Environmental Protection Agency in the US was not aware of any studies having been done on the impact of offshore fracking as the practice has long been viewed as “a somewhat short-term discharge and often mixed with other discharges.”
To frack some of the world’s biggest offshore wells, roughly seven million pounds of people and gear, including rock-crushing engines and tons of sand to prop open cracks in the rock, must be crammed onto a 300-foot-long ship, called a stimulation vessel.
Deep-water wells cut through multiple pancaked layers of oil-soaked rock, and each layer must be fracked to get the most oil out -- a task that can take a full day to get to the bottom of the well. Halliburton and others have figured out a way to save time and money by fracking all those layers in one trip down the well, instead of doing each layer separately.
The more intense fracking means larger volumes of water, sand and equipment are needed to coax more oil out -- and bigger boats to carry it all.