Beneficial Use Matrix – Industrial Use
Industrial Use during Oil and Gas Production
Dust Control
Some oil and gas regulatory agencies allow operators to spray produced water on dirt roads to control the dust. Generally, this practice is controlled so that produced water is not applied beyond the road boundaries or within buffer zones around stream crossings and near buildings1. Produced water used for dust mitigation must have TDS and sodium levels that meet BLM and other regulatory standards2. Environmental concerns associated with dust mitigation using produced water include:
- Salt build up along roadways;
- Migration of water and associated pollutants off the roadway;
- Impacts to vegetation;
- Salt loading to river systems
In addition to salt-related concerns, impacts of other pollutants in produced water must be considered. These include hydrocarbons, heavy metals, and chemical additives used during drilling, stimulation, or workover of the wells. It is very difficult to obtain information on the concentrations of treatment chemicals and additives in produced water2.
The use of produced water would be voluntary; however, ultimate approval to do so would be up to the state authority that has primacy over the disposal and use of produced water. It may also be necessary to include the states in the implementation of any permitting process related to roadspreading because these agencies have the expertise and develop the environmental standards related to surface and groundwater pollution. There is a precedent for involving environment departments. In WY, although the Oil and Gas Conservation Commission is responsible for permitting roadspreading applications, the operations must also be approved by their Department of Environmental Quality2.
Hydraulic Fracturing
Some natural gas wells need hydraulic fracturing to enhance production operations. Each "frac job" requires hundreds of thousands of bbl of water. Local water supplies may not be adequate to meet the demand for frac water, and trucking of frac flowback water off-site for disposal may be very expensive. Produced water or frac flowback water can be treated and reused for new frac jobs. Reuse of produced water to supply oil and gas exploration activities might help taking some stress off the local water supply to meet the demand.
Drilling Operation
For drilling operations, produced water should be free of hydrogen sulfide, which reacts with water to form a weak acid that is very corrosive to drilling equipment3. Drilling water quality requirements may be different and dependent on the drilling program. An example of drilling water quality requirements is: TDS < 20,000 mg/L and calcium < 400 mg/L for shallow drilling or calcium < 100 mg/L for deep drilling.
References
- Produced Water Management Technology Descriptions Fact Sheet 2009, http://www.netl.doe.gov/technologies/pwmis/techdesc/
- OGWG, Oil & Gas Work Group of the Four Corners Air Quality Task Force. Oil & Gas, 2007, http://www.nmenv.state.nm.us/aqb/4C/Docs/ Mobile_NonRoad_4CAQTF_Draft_Report_vers_6_042507.doc
- Peacock, P., Beneficial use of produced water in the Indian Basin Field: Eddy County, NM, 2002 Ground Water Protection Council Produced Water Conference, Colorado Springs, CO, October 16-17, 2002.