Oil and natural gas recovered from resource plays are widely considered to be the next step forward in the fossil-fuel or hydrocarbon recovery challenge.
In a conventional oil and gas field, vertical wells are drilled into conventional sandstone and carbonate hydrocarbon reservoirs, which can be as deep as one to six miles beneath the surface. With resource plays, the oil and natural gas trapped in unconventional, low porosity and permeability, sandstone, carbonate and shale formations is accessed by horizontal well bores of up to two miles in length.
The oil and natural gas is brought to the surface using a technique known as hydraulic fracturing, which fractures these reservoirs and allows the flow of hydrocarbons to the surface. The success of hydraulic fracturing in these unconventional reservoirs is driving the explosive growth of exploiting these previously nonproducing reservoirs. Hydraulic fracturing employs large volumes of water, proppants such as sand or bauxite, and chemicals), to open fractures in the reservoir rock that in turn allow the flow of gas or oil to the surface. An energy company will typically use between 3,000,000 and 5,000,000 gallons of water to hydraulically fracture a single well.
Hydraulic fracturing fluids are created by taking fresh or brackish water, and mixing the water with chemical additives such as biocides to eliminate the aerobic and anaerobic bacteria found in the source water, and scale inhibitors, to prevent chemical corrosion within the steel-cased wellbore. After the hydraulic fracturing process occurs, this fluid returns to the surface as flowback and produced water via the well bore.
Oil and gas producers are then forced to deal with these wastewaters. These wastewaters are typically contaminated with highly resistant bacteria, biofilms, sulfur, heavy metals and high concentrations of salt that also comes from the formation.
The conventional method of handling this wastewater is to dispose of it either in deep injection disposal wells or in evaporation ponds. These methods require extensive trucking of the water, which is expensive and harmful to the environment. To counteract this expense and harm, Biolargo developed its AOS, which is currently being optimized for use by oil and gas operators around the globe to treat and recycle their flowback and production waters.
Typically, the AOS can used at the well site to condition flowback and production fluids in order to create clean brine. This bacteria and scale free fracturing fluid is then used to hydraulically fracture oil and natural gas wells. This allows operators to reduce their water consumption, control their water handling, transportation and treatment costs and to reduce their overall environmental impact.