Oil and Gas at Your Door? (2005 Edition) - Earthworks

Oil and Gas Development and Impacts
material. This may create a site with the potential for great soil volume change, and possibly
damage to surface structures. The common practice for disposing of drilling muds is
to either bury the mud reserve pit, or discharge the mud to the surface. For landowners
who may want to build on what was previously a drill site, it is worth noting that in order
to be eligible for FHA mortgage insurance, all unstable and toxic materials must be
removed and the pit must be filled with compacted selected materials. 63
• Wastes that may be associated with drilling fluid include oil derivatives (e.g., PAHs), spilled
chemicals, and empty containers. 64 Drilling muds that circulate through the well and
return to the surface may contain dissolved and suspended contaminants including cadmium,
arsenic, and metals such as mercury, copper and lead; hydrocarbons; hydrogen
sulfide and natural gas, 65 as well as drilling mud additives, many of which contain potentially
harmful chemicals (e.g., chromate, barite).
Drill Cuttings
• The main toxic agents in drilling cuttings are oil and oil products. These accumulate in the
solid phase of drilling cuttings when crude oil and oil-based drilling fluids contact cuttings
during the drilling process. 66 Rock cuttings may also contain arsenic or metals depending
upon the geology. 67
• Cuttings may be spilled around the well pad due to high pressures, dangerous working conditions,
and lack of government oversight of drilling operations. 68
• In West Virginia, the Department of Mines, Minerals and Energy (DMME) received complaints
from residents about soap bubbles flowing from residential faucets. The DMME
attributed this to the drilling process associated with coalbed methane well installation.
Soaps and other substances are used to extract drilling cuttings from the borehole because
the foam expands and rises. As it rises, it carries the cuttings to the surface. During drilling
of the shallow portion of the well (and before the required groundwater casing is cemented
in place) these drilling fluids may migrate from the borehole into the groundwater zone
that supplies private wells. In the incidents of soap contamination in West Virginia, water
was provided to the affected residents until the soaps were completely purged from the
area surrounding their water well. 69
Waste Disposal
• Onshore oil production operations produce quantities of cuttings and mud ranging from
60,000 to 300,000 gallons per day. Lined pits for disposal and storage are sometimes
used, but mud, drill cuttings and other materials are often discharged into unlined pits,
allowing potentially toxic substances to seep into the ground. 70 If improperly fenced, these
pits can be a hazard for livestock and wildlife.
• While it is common for oil and gas companies to drain off fluids from drilling mud pits, it is
very common for companies to simply bury the remaining solids in place or spread them on
the lease site. 71
Blowouts
• Well blowouts are rare, but can be extremely serious. Blowouts have been known to completely
destroy rigs and kill nearby workers. They are most likely to occur during drilling, but
can occur during any phase of well development including production (especially during
well workover operations). If the pressure exerted by the geological formation is much higher
than that exerted by the drilling fluid, then the gas, oil or other fluids in the well may rise
uncontrollably to the surface. Equipment that is within the well may also be thrust to the
surface. If there is a significant quantity of natural gas in the blowout materials, the fluid
may ignite from an engine spark or other source of flame. Some blowouts are controlled in
a matter of days, but others have taken months to cap and control. 72 The section on Impacts
Associated with Oil and Gas Operations has more information on blowouts.
I-12