PRODUCED WATER ACCOUNTING AND CHARACTERISTICS: THE CASE OF HYDRAULIC FRACTURING IN TEXAS

The rapid growth of hydraulic fracturing to extract oil and gas from low- to very low-permeability formations (shales and other tight formations) has drawn attention to the fate of the so-called flowback and produced waters. In Texas, reporting to the regulatory state agency allows for a reasonable accounting of the volumes handled. We will present a life-cycle analysis of water in selected unconventional plays of the state. As expected, amounts of produced water vary though time and space. In addition, these by-products of the hydrocarbon production process can be considered waste or resource. In Texas, recycling and reuse of produced waters from unconventionals for additional fracturing operations is not widespread, mostly because of the abundance of injection wells available for disposal. However, in order to limit competition with other users and to reduce the amount of fresh water consumed –fresh water is typically used for hydraulic fracturing- in a state with periodic, sometimes severe, droughts and a fast growing population, more and more operators have started considering flowback and produced water as a resource. Cost of treatment is often cited as a barrier controlling a more widespread use of this resource. We will also explore through laboratory experiments the more fundamental aspects of rock-water interactions between hydraulic fracturing fluid and host rock as it relates to the composition of the flowback / produced waters.