Feasibility and Design Approach for Automated Classification and Segregation of Early Flowback Water for Reuse in Shale-Gas Hydraulic Fracturing
Large volumes of water (1-6 million gallons containing chemical additives, friction reducer and sand propant) are required for the completion of a typical shale gas well. Approximately 10 to 50 percent of this “fracwater” is produced as “flowback” water during the initial weeks of fluid production.
Document Type
Report
Report Type
Topical Report
Report Period
July 2011
Author(s)
L. Peter Galusky, Jr., Ph.D., P.E.; Thomas D. Hayes, Ph.D.
Corporate Source
Gas Technology Institute (GTI)
Sponsor
Research Partnership to Secure Energy for America (RPSEA)
Feasibility and Design Approach for Automated Classification and Segregation of Early Flowback Water for Reuse in Shale-Gas Hydraulic Fracturing
Barnett and Appalachian Shale Water Management and Reuse Technologies
RPSEA Report No: 08122-05.06
The rate of flowback water production is usually highest in the first day and rapidly decreases with time to a very low flow within a month to several weeks of a well completion. Shale gas flowback water contains various inorganic salts that increase in concentration over time from the onset of flowback production until flowback diminishes.
An effort was made to characterize flowback waters from a limited number of shale gas well completion locations in the Barnett Shale. This characterization included measurements of cumulative volume, electrical conductivity and selected constituents of interest (inorganic salts) in flowback water samples taken over time from each location. This report summarizes these data and examines the feasibility of using real-time electrical conductivity measurements to identify and segregate early flowback waters containing relatively low concentrations of total dissolved solids (TDS). Such low TDS early flowback water has potential for reuse in well drilling and completion with only relatively minor pre-treatment for its intended purposes. This could serve to significantly reduce the quantity of fresh water that is presently used to drill and complete shale gas wells and to reduce the total quantity flowback water that needs to be disposed. This could lead to significant logistical efficiencies and economic savings with respect to water acquisition, handling, trucking and disposal.
