When Colonel Edward Roberts of New Jersey fought in the battle of Fredericksburg, Virginia in 1862, he noticed the effect the Confederate artillery had on a canal on the battlefield. It gave him the idea for what is now known as fracking, the popular short term for hydraulic fracturing.
Fracking today involves injecting a combination of water, sand and chemicals under high pressure into a rock formation where a natural gas or oil reservoir is found. The process fractures the strata, releasing larger amounts of gas or oil than would otherwise be obtained by drilling alone. The high-tech methods used today are in sharp contrast to the first attempts, which relied on the use of torpedoes.
Col. Roberts devised the Roberts Torpedo, which was filled with gunpowder (later nitroglycerin), and lowered into a well. The hole would be filled with water which would "tamp" the explosion, preventing it from being directed upwards (thus putting his battlefield observations to practical use). This also enhanced the fracturing of the soil containing the oil reserves.
The results were immediate — some wells boosted production by 1,200% in just one week — and the Roberts Petroleum Torpedo Company was born. Although Roberts obtained a patent on the Roberts Torpedo in 1866, many tried to circumvent his substantial fees by mimicking his methods late at night, coming to be known as "moonlighters." Roberts charged a minimum of $100 per torpedo and received a one-fifteenth share of the increased oil flow. Roberts spent $250,000 to pay Pinkerton detectives to find and stop moonlighters, and lawyers to prosecute them.
Cement casing of the borehole was developed in 1919 and was designed to guard against collapse. However, this necessitated the invention of methods to break through the casing. In the 1930s, Ira McCullough invented a multiple bullet-shot casing perforator which would shoot projectiles through the borehole casing and into the surrounding strata, and that became the popular method. Acid treatments were also used in the process during this time.
During World War II, Swiss chemical engineer Henry Mohaupt came to the U.S. where he led the invention of the bazooka, the shoulder-fired rocket-propelled grenade launcher. After the war, he was recruited by the Well Explosives Company in Fort Worth, Texas, to develop the idea of a conically shaped explosive charge to perforate oil drill casings as well as the surrounding formations. He obtained a patent for his "Shaped Charge Assembly and Gun" in 1951.
The first experimental hydraulic fracturing, which used napalm and sand, took place in 1947 in the Hugoton gas field in southwestern Kansas. This was based on the research of Floyd Farris of Stanolind Oil and Gas Corporation, who looked at the relationship between treatment pressures and well output. The first commercial fracking occurred in 1949 in Oklahoma and Texas by the Halliburton Oil Well Cementing Company, which was granted an exclusive license and a patent. The patent expired in 1968, leaving the door open for other companies to follow.
The type of fracking done today was first used in 1998 to extract shale gas. Sometimes called horizontal slickwater fracking, this method can use various fluids, including gels and foams. Fracking uses a "proppant," a material that will help keep the hydraulic fracture open. Sand is usually used for this purpose, but ceramics are used as well, since the substance must be porous enough to allow the flow of gas or oil to the well, but still be strong enough to keep the fracture from closing.
Fracking supporters say that it boosts local economies and frees up needed oil and gas reserves. Opponents argue that it contaminates ground water, causes other environmental problems through the disposal of contaminated wastewater and leaking of methane, and triggers earthquakes. The process became more controversial after the release of the documentary "Gasland" in 2010 by filmmaker Josh Fox.
Fracking has been subject to state regulation, but is becoming increasingly subject to federal regulation in the U.S. The EPA now requires the installation of equipment to reduce air pollution by January 2015, and a draft rule was issued earlier this year by the Department of the Interior to require companies to disclose the chemicals they use in the fracking process and to have a water management plan in the event that chemical fluids should escape.
As fracking becomes more controversial, scientists are looking for ways to reduce its environmental impact. University of Minnesota researchers have recently developed a method to clean fracking waste-water by using bacteria encased in tiny beads of silica gel. The bacteria destroy the contaminants in the waste-water without contaminating it themselves by remaining encapsulated in the gel.