Natural gas, an abundant resource in the United States, offers significant advantages compared to other fossil fuels in terms of both environmental impact and economic security. The technology of hydraulic fracturing, pioneered in the 1940?s, has been recently transformed, leading to the economical production of stranded natural gas. An economical and reliable source of natural gas is essential for the energy sector as well as the chemical industry. Unfortunately, the public opinion is concerned about the possibility of environmental issues that might be traced back to the unregulated practice of hydraulic fracturing.
This proposal requests support to organize a two-day workshop in Washington, D.C. to identify fundamental research needs of hydraulic fracturing in the general areas of interfacial and transport phenomena that could potentially enable the sustainable deployment of shale gas extraction. Researchers from academia, industry, and government will address this topic in an open forum and provide recommendations on how to employ current and future research capabilities. Topics include:
a) General observations (details concerning the fracture technology, current and future utilization of natural gas, seismic technologies to probe shale formations, the effect of carbon dioxide on rock formations, water quality where hydraulic fracturing is practiced) b) Methane hydrates c) Transport in dual-permeability media d) Role and fate of the fracture fluids chemicals e) Thermodynamic properties of compounds used in fracture fluids, including complex mixtures containing water, natural gas, and carbon dioxide f) Water usage and disposal g) Simultaneous natural gas extraction and carbon dioxide sequestration
Broader Impacts:
The primary outcomes expected from the proposed workshop are recommendations for future research needs that will benefit the economical and environmentally-benign extraction of natural gas from shale formations. This workshop will bring together scientists from industry, academia, and the government. The PI will broadcast recommendations to the community via one review article that will be submitted for publication in a scientific journal. A summary of the workshop discussion will be published on the World Wide Web. An executive report will be submitted to NSF within two months of the workshop. A detailed report will be submitted to NSF within six months from the end of the workshop.
Funds provided by the National Science Foundation under the present award have been used exclusively to organize a workshop, titled: Identification of Fundamental Interfacial and Transport Phenomena for the Sustainable Deployment of Hydraulic Shale Fracturing – Role of Chemicals Used The workshop took place on May 14th-15th, 2012, in Arlington, VA. We selected the location because it offered affordable accommodation for all participants, economical and relatively easy travel for the participants (the attendees were from the United Kingdom, California, Texas, Oklahoma, Pennsylvania, Washington D.C., New York, Ohio, Wisconsin, Illinois, New Mexico, etc.), and participants from governmental agencies could attend. The full summary of the report, inclusive of list of speakers, titles of the presentations, and recommendations has been delivered to the National Science Foundation. A copy of the report is available via the internet at: http://hotohke.ou.edu/~astriolo/HydraulicFracturingWorkshopReport.pdf A more concise summary, focused primarily on the research needs that have been identified at the workshop, has been recently published in the following commentary: A. Yethiraj, A. Striolo, Fundamental Physical Chemistry Topics Relevant for Hydraulic Fracturing, invited commentary, J. Phys. Chem. Lett. 4 (2013) 687-690. The goal of the workshop was to bring together industry, academia, governmental agencies, and national laboratories to discuss some fundamental issues related with hydraulic fracturing. The National Science Foundation programs who funded this workshop are ‘Interfacial Processes and Thermodynamics’, ‘Particulate and Multiphase Processes’, and ‘Fluid Dynamics’. The discussion focused primarily on topics of interest to these programs. The industrial representatives were extremely helpful in identifying several fundamental topics that could be addressed by the academic community, in collaboration with industry and national laboratories, to better understand the physical processes involved in the operation of hydraulic fracturing. For example, topics that require fundamental investigations include, but are not limited to the fate of water within the shale formations, the treatment of water once it returns to the surface after the operation and during the production of natural gas and oil, understanding the rock properties and how they depend on the fluid loading, the transport of fluids (natural gas, oil, but also water and perhaps carbon dioxide) within the narrow pores in the shale formations, the complete characterization and diversification of various shale formations (we learned that the properties of the shales in the Marcellus region are different, for example, compared to those in the Barnett region), the invention of new additives that could be as effective as existing ones, but at conditions of high salinity (this would allow practitioners to use salty water instead of fresh water in the fracturing operations), etc. It was argued that fundamental understanding of these processes could lead to more economically attractive development of shale formations with less, if any, environmental impact.
