Proper site selection, well design, construction and operating procedures are critical to protect against spills and failures of surface equipment or wells that could contaminate water supplies.
At ConocoPhillips, we believe the risk associated with well operations, including those involving horizontal drilling and hydraulic fracturing, is very low, yet it is important for us to manage these risks effectively.
We are confident in our ability to develop abundant, clean-burning natural gas resources responsibly by using proven practices. We believe prudent regulations help promote safe operations that protect the environment, and we support the public disclosure of fracturing fluid content as part of effective state regulations.
Multiple Safeguards Protect Groundwater
A well is much more than a pipe in the ground. It is constructed with redundant barriers of steel and cement designed to protect aboveground and underground sources of drinking water throughout the life of the well.
Looking at a cross section of a well, the outermost structure typically includes a shallow conductor casing to stabilize the ground at the well surface and always includes surface casing. The surface casing extends to depths below potential freshwater aquifers in accordance with government regulations and is cemented in place to protect useable groundwater. Inside the surface casing, there may be one or more intermediate casings. The innermost structure is the production casing that extends to the bottom of the well. Cement is pumped into the open space between each casing and the rock, forming a complete seal with multiple layers of protection. The casing and cement system is pressure tested to ensure its integrity.
Beyond these mechanical safeguards, groundwater is protected by physical factors, such as large vertical distances and the presence of natural geologic barriers. These barriers can consist of multiple layers of impermeable rock that separate the target formations from aquifers by thousands of feet.