Hydraulic fracturing is essential to producing energy resources from tight rock and shale formations; without it, production cannot economically occur. In 2011, Anadarko participated in the drilling of more than 1,800 wells in the U.S. onshore – approximately 80 percent of which required hydraulic fracturing. Hydraulic fracturing is generally applied to formations that are more than a mile below the surface (4,000 to 14,000 feet); whereas, potential sources of ground water typically reside much closer to the surface (between 100 and 500 feet). Hydraulic fracturing involves the injection of fluid (generally consisting of water, sand and a proportionately small amount of additives) under pressure through multiple protective layers of steel pipe, concrete and rock into a pre-determined oil or natural gas-bearing formation. The water and pressure open microscopic pathways, which are propped open by grains of sand. These pathways allow the natural gas or oil to flow to the wellbore and ultimately be produced at the surface. For a general demonstration of the hydraulic-fracturing process, please view this informational video at Energy from Shale.
Hydraulic Fracturing Committee
In October 2012, Anadarko formed a Hydraulic Fracturing Committee that will assist the company’s management in continuously monitoring, evaluating and addressing matters related to its hydraulic fracturing operations.
What’s in it?
The ingredients used in fracture-stimulation fluids vary according to geology. In general terms, water makes up more than 90 percent of the solution; sand or proppant constitutes approximately 9 percent; and additives make up less than 1 percent of the total volume. The relatively small amounts of additives generally consist of friction reducers, biocides to prevent bacterial development and scale inhibitors. This pie chart available at FracFocus shows a general breakout of fracing ingredients.
Cross-section of a Typical Horizontal Well