feasibility assessment shal-water

Download Feasibility assessment  shal-water

Post on 02-Dec-2014

732 views

Category:

Technology

5 download

Embed Size (px)

DESCRIPTION

 

TRANSCRIPT

  • 1. RPSEAFeasibility Assessment of Early FlowbackWater Recovery for Reuse in Subsequent Well Completions Report No. 08122-05.07 Barnett and Appalachian Shale Water Management and Reuse Technologies Contract 08122-05 October 24, 2011 Principal Investigator Project ManagerL. Peter Galusky, Jr., Ph.D., P.E. Thomas D. Hayes, Ph.D.Principal Environmental Engineer Coordinator, Environmental Texerra Engineering Solutions Monument, CO Gas Technology Institute 1700 S. Mount Prospect Rd. Des Plaines, IL
  • 2. LEGAL NOTICEThis report was prepared by the Gas Technology Institute as an account ofwork sponsored by the Research Partnership to Secure Energy forAmerica, RPSEA. Neither RPSEA members of RPSEA, the National EnergyTechnology Laboratory, the U.S. Department of Energy, nor any personacting on behalf of any of the entities: a. MAKES ANY WARRANTY OR REPRESENTATION, EXPRESS OR IMPLIED WITH RESPECT TO ACCURACY, COMPLETENESS, OR USEFULNESS OF THE INFORMATION CONTAINED IN THIS DOCUMENT, OR THAT THE USE OF ANY INFORMATION, APPARATUS, METHOD, OR PROCESS DISCLOSED IN THIS DOCUMENT MAY NOT INFRINGE PRIVATELY OWNED RIGHTS, OR b. ASSUMES ANY LIABILITY WITH RESPECT TO THE USE OF, OR FOR ANY AND ALL DAMAGES RESULTING FROM THE USE OF, ANY INFORMATION, APPARATUS, METHOD, OR PROCESS DISCLOSED IN THIS DOCUMENT.THIS IS AN INTERIM REPORT. THEREFORE, ANY DATA, CALCULATIONS,OR CONCLUSIONS REPORTED HEREIN SHOULD BE TREATED ASPRELIMINARY.REFERENCE TO TRADE NAMES OR SPECIFIC COMMERCIAL PRODUCTS,COMMODITIES, OR SERVICES IN THIS REPORT DOES NOT REPRESENTOR CONSTIITUTE AND ENDORSEMENT, RECOMMENDATION, ORFAVORING BY RPSEA OR ITS CONTRACTORS OF THE SPECIFICCOMMERCIAL PRODUCT, COMMODITY, OR SERVICE.
  • 3. Table of ContentsAbstract ................................................................................................................................ 4Introduction .......................................................................................................................... 6Objectives and Scope .......................................................................................................... 7Methods ............................................................................................................................... 7Results and Discussion ........................................................................................................ 8 Flowback Rates and Volumes .......................................................................................... 8 Flowback Chlorides and Total Dissolved Solids ............................................................. 14 Observed Relationships in Flowback Water Quality versus Flowback Quantity ............. 18 Optimizing Flowback Water Segregation for Potential Reuse ........................................ 22 Total Flowback Water Reuse Possibilities and Constraints ......................................... 25Conclusions........................................................................................................................ 29Acknowledgments .............................................................................................................. 32References ......................................................................................................................... 32Appendix ............................................................................................................................ 34 APPENDIX A Individual Well Flowback Measurements and Model Estimates ............ 35 APPENDIX B Flowback Chloride Concentrations vs Cumulative Frac water Recovery for Six Individual locations .............................................................................................. 48
  • 4. List of FiguresFigure 1: 1a (above) and 1b (below) Daily flowback rates (Figure 1a) and accumulateddaily volumes (Figure 1b) averaged among eleven Barnett Shale locations (black dots) andmodeled using exponential (red lines) and hyperbolic (blue lines) functions. ..................... 12Figure 2: (above) and 2b (below) Modeled flowback rates (Figure 1a) and accumulatedvolumes (Figure 1b) estimated for eleven averaged Barnett Shale locations. Error barsindicate the magnitudes of +/- one standard deviations among the eleven locations. ........ 13Figure 3: Flowback chloride concentration versus cumulative fraction of frac waterrecovered, averaged among six locations in the Barnett Shale. ......................................... 14Figure 4: TDS versus chloride from four Shale Barnett locations. ..................................... 15Figure 5: TDS versus specific (electrical) conductance from four Shale Barnett locations. 16Figure 6: TDS concentrations shown with the drop in flowback rate, calculated for a typicalwell by modeling flowback rate using hyperbolic decline with parameters averaged amongeleven Barnett locations. .................................................................................................... 17Figure 7: The rate of change in TDS accumulation shown with the drop in flowback rate,calculated for a typical well by modeling flowback rate using hyperbolic decline withparameters averaged among eleven Barnett locations. ..................................................... 18Figure 8: 8a & 8b Flowback TDS concentrations (projected based on the average patternobserved from six locations) versus flowback day (8a, above) and cumulative percent fracwater recovery (8b, below). ................................................................................................ 20Figure 9: Cumulative mass of recovered TDS (in flowback) versus cumulative flowbackwater mass. ........................................................................................................................ 21Figure 10: Potential direct reuse of flowback as a function of maximum TDS threshold.These projections are based on a well completed with 100,000 bbls of frac water flowingback at an initial rate of 2,000 bbls/d and yielding 40,000 bbls of recovered frac water asflowback. ............................................................................................................................ 22Figure 11: Volume-weighted flowback dilution factors to meet specified TDS criteria inrelation to the cumulative fraction of frac water recovered. ................................................ 24iiOn the Reuse of Shale Gas Flowback Water
  • 5. Figure 12: Cumulative flowback dilution volumes required to meet specified TDS criteria inrelation to the cumulative volume of frac water recovered. ................................................ 24Figure 13: Per-well modeled flowback rate and cumulative volume. ................................. 26Figure 14: Time course of per well modeled TDS and chloride concentrations. ................ 26Figure 15: a (above) and b (below) - Summary of key metrics for flowback reuse for ahypothetical scenario in the Barnett Shale. ........................................................................ 28iiiOn the Reuse of Shale Gas Flowback Water
  • 6. Feasibility Assessment of Early Shale Gas Flowback WaterRecovery for Reuse in Subsequent Well CompletionsAbstractFresh water is critical for natural gas production in the Barnett Shale, where in excess of 3to 5 million gallons are required for the completion of each gas well. The financial costs,logistical challenges and public relations concerns over the use of fresh water supplies thusimpel Barnett gas producers to use less fresh water and to use it more efficiently. Theobjectives of this work were to develop a simple, empirical modeling approach forcharacterizing and forecasting flowback water rates and total dissolved solids (TDS) and touse such models to characterize the efficacy of flowback water recycling based onpredefined TDS reuse criteria.Approximately one third of the fracwater used for a typical Barnett Shale well is recoveredfrom the initiation of blowback until the time that the well produces salable volumes ofnatural gas. Flowback water production could be efficiently described and modeled usingeither an exponential or hyperbolic equation; (these are commonly used in forecastingpetroleum and natural gas production). Both models were found to be particularly sensitiveto the initial flowback rate, which unfortunately tends to be rather erratic during the first fewdays of flowback production. It is suggested, therefore, that the initial value used notnecessarily be that of the first day of flowback, but may be averaged among the first threeto five days or otherwise adjusted so that the resulting flowback rate and production curvesfollow a reasonable course.Flowback chloride and TDS concentrations were efficiently described by a power functionof cumulative flowback. The rate of change in flowback TDS concent

Recommended

View more >