Well stimulation flowback water generally contains the chemicals and/or byproducts of a hydraulic fracturing process used on a specific well. Produced water is a different category, which is naturally occurring formation brine that is produced along with the hydrocarbons from the well, and can contain large quantities of dissolved salts, dispersed hydrocarbons, and other materials. Both of these waters are considered waste by-products of oil and gas production and typically present logistical difficulties for operators. Some of the challenges include transportation of waste water over long distances as well as local government and environmental regulations related to the safe disposal of the water from oil fields.
The ability to recycle flowback and produced water provides great opportunities for service providers and producers to help reduce the total amount of fresh water that is used in their operations. By reducing the volumes of fresh water that are used in hydraulic fracturing and, at the same time, reducing the amount of flowback and produced water that has to be transported and disposed, operators are able to show their commitment to the community, the environment and can potentially minimize logistics. These benefits, however, can come with difficulty. For example, the cost of purifying flowback and produced water to near potable quality might not be financially feasible, while bypassing treatment entirely can pose difficulties in using the water effectively for fracturing fluids. In this paper, new and customized fluid compositions that can be used effectively with recycled waters are discussed, as well as successful case studies.