liquid and solid waste streams in appalachian basin unconventional gas by paul ziemkiewicz, phd

WEST VIRGINIA UNIVERSITY WV Water Research Institute

Liquid and solid waste streams in Appalachian Basin unconventional gas

Paul Ziemkiewicz, PhDWater Research InstituteWest Virginia University


LIQUID WASTE STREAMS

• Origins• Volumes• Chemistry

– Inorganics– Organics– NORM-naturally occurring radioactive materials


TERMINOLOGY: LIQUIDS• Makeup water-impoundments/tanks

– fresh water– waste water

• Hydraulic fracturing fluid-frac fluid~ 100,000 to 120,000 bbl injected

– Makeup water +– Proprietary mixture of chemicals– Proppant

• Flowback-produced water Fluids returned from the well after frac~70-90% lost in formation

• Recycle– Flowback-produced water used for makeup


FLUIDS AT THE WELL SITEIf major local well completions: Hydrofracing is a net consumer of water

If not: then about


PRODUCED WATER PROFILE

Flowback ^Q ^Q day (bbl/day) (gpm)

1 4711 13730 392 1160 236 790 176 5

180 106 3360 64 2

The decline in produced water returns varies from well to well, not well documented out to 10 years


CHEMICAL CHARACTERIZATION

•Flowback/produced water•Recycled flowback + makeup water + additives

•Hydraulic fracturing fluid•Drilling mud


Flowback: predominantly Na, Ca, Cl

FPW 4 FPW 5 FPW 3 FPW 2 FPW 1

TDS 189,000 104,000 38,700 12,610 8,800

Cl 107,000 65,000 17,100 7,172 6,575

Na 48,100 33,700 8,560 2,863 3,550

Ca 22,200 12,800 1,640 1,749 319

Mg 2,000 1,470 193 122 31

Sr 2,970 1,440 301 nd nd

K 668 444 243 57

SO4 49 414 28 71 99

Ba 1,300 176 175 nd 27

Fe 48 30 37 27 37

pH 5.7 6.3 7.4 6.1 7.6

TSS 519 570 99 220 44 O&G 3 nd 5 49 5

Flowback inorganic chemistry from five Marcellus wells (mg/L)


Nearly all parameters were higher in flowback than frac fluid Pink: exceeds drinking water MCL

Inorganics Organicsunits MCL frac fluid flowback

As mg/L 0.01 - - Ba mg/L 2 5.7 514.7 Cr mg/L 0.1 - 0.0 Hg mg/L 0.002 - -

Nitrate mg/L 10 - 0.0 Nitrite mg/L 1 - 0.1

Pb mg/L 0.015 - 0.0 Se mg/L 0.05 - 0.1

Ag mg/L 0.1 - - Al mg/L 0.05 0.1 1.4 Cl mg/L 250 4,712.3 42,683.1 Fe mg/L 0.3 9.1 67.1 Mn mg/L 0.05 0.6 5.5 pH mg/L 6.5 7.2 6.6

SO4 mg/L 250 65.7 38.7 TDS mg/L 500 9,369.5 74,710.8 Zn mg/L 5 0.5 0.1

Br mg/L 54.6 466.0 Na mg/L 2,202.5 26,202.3 Sr mg/L 62.6 1,365.4

units MCL frac fluid flowbackBenzene µg/L 5 7.4 149.6

Ethylbenze µg/L 700 2.2 52.5Toluene µg/L 1000 22.1 621.7

Xylene (m,p) µg/L 10000 41.0 698.7Xylene (o) µg/L 10000 8.8 142.3

Xylene (total) µg/L 10000 49.8 841.0

Styrene µg/L 100 0.0 10.8

MBAS mg/L 0.5 0.0 0.2COD mg/L 539.5 1420.1O&G mg/L 6.0 63.5TOC mg/L 105.4 176.4

Ethane µl/L 0.0 571.2Methane µl/L 88.5 3420.5Propane µg/L 0.0 86.9

TPH (Diesel) mg/L 38.7 60.6TPH (Gas) mg/L 1.6 25.8TPH (Oil) mg/L 3.3 10.2


Cation:Cl ion pairs dominate in FPWequivalents

ion pairs? PA well WV well

Sr SrCl2 114.2 50.2

Mg MgCl2 160.5 250.2

K KCl 99.7 176.5

Na CaCL2 2,756.5 1,487.0

Ca NaCl 1,177.1 1,835.4

cation sum 4,308.0 3,799.3

Cl 4,197.2 3,526.8

% Cl 103% 108%


IN FPW CHLORIDE IS THE DOMINANT ANION:SOLUBILITY VS. SULFATE AND CARBONATE MINERALS


FLOWBACK EVOLUTION-MAJOR INORGANIC IONS

Ziemkiewicz et al., 2011 Hayes 2009


FLOWBACK EVOLUTION-ORGANICS

Ziemkiewicz et al., 2011 Hayes, 2009


EVIDENCE THAT SULFATE PRECIPITATES TO FORM SCALE

2,920 mg SO4 in HF fluid 11 mg SO4 in HF fluid

If this SO4 precipitated as SrSO4, it would form 4 t/day of scale over the first week


WATER TREATMENT TECHNOLOGIES FALL INTO SIX MAIN CATEGORIES:

treatment1. Bulk filtration2. Lime softening3. Sulfate addition4. Nano filtration

5. Reverse osmosis6. Evaporation/Crystallization

removes1. suspended solids2. Mg, Ca –as carbonates3. Sr, Ba, Ra- as sulfates4. multivalent ions: Fe, Mg, Ca, Sr,

Ba, SO4

5. All ions6. All inorganic ions


COSTS INCREASE

FROM LEFT TO RIGHT

Treatment end points

Sulfate addition

Nanofiltration

Reverse osmosis

Costs:pre treatmentsolids disposaltransportationdisposal fee

Bulk filtration:TSS/Organics

surface dischargerecycle Deep well injection



Lime softening

Evaporation/Crystalization

Costs:transportationsolids disposal

Costs:astronomical

Do not over treat your

water


SUMMARY• Shale gas development creates large volumes of

contaminated waste water• Pollutants include inorganic and organic constituents• Most flowback water is recycled• Recycling is contingent on nearby well development• Need efficient treatment for end of life cycle waste

water


TERMINOLOGY: SOLID WASTES• Drilling mud

– Returns to the surface with cuttings during drilling– Recycled after cuttings removed– To disposal after well completed

• Drill cuttings – Rock fragments-clay to fine gravel– ~500-800 tons/well or 25 to 50 truckloads– To disposal after separation from drilling mud

• Flowback Solids-filter cake, precipitates, suspended solids


DRILLING WASTESMud Cuttings


SOLIDS SEPARATIONCuttings pit

Flowback pit

Plate and frame filter press

Bag filters

Flowback tank


Liquid fraction: Drill Cuttings% samples > TCLP limit

Drill %>Cuttings TCLP min max

Cr 100% 6.7 32.8 mg/LAs 90% 2.4 30.6 mg/LPb 80% 3.5 84.9 mg/LBa 70% 23.9 7,870.0 mg/L

Benzene 70% 0.0 300.0 µg/LSe 40% 0.0 3.3 mg/LHg 10% 0.0 0.3 mg/L

Drill Cuttings: Vertical Section


Radioactivity: Naturally occurring radioactive materials (NORM)• Flowback/produced water• Drill cuttings• Drilling mud• Special handling as dictated by exposure risk


Radioactive isotopes increase during flowback


FLOWBACK SOLIDS ARE MORE

RADIOACTIVE THAN VERTICAL DRILLING MUDS/CUTTINGS:

BUT IS THE DIFFERENCE SIGNIFICANT?

Vertical only MarcellusDrilling mud solid

samplesFlowback

solidsSolids units average Donna C pit

Gross Alpha pCi/g 17.35 65.10Gross Beta pCi/g 25.22 28.80

Potassium-40 pCi/g 24.51 19.69Radium-226 pCi/g 1.22 26.95Radium-228 pCi/g 1.33 5.12Thorium-228 pCi/g 1.23 2.33Thorium-230 pCi/g 1.01 1.10Thorium-232 pCi/g 0.90 1.11Uranium-234 pCi/g 0.91 1.08Uranium-235 pCi/g 0.03 0.07Uranium-238 pCi/g 0.85 0.69Alpha + beta pCi/g 42.6 93.9

gamma pCi/g 32.0 58.2Total pCi/g 74.6 152.1


POTENTIAL EXPOSURE PATHWAYS:

• Migration from horizontal leg to surface/shallow groundwater

• Poor casing/cement integrity• Handling failures at the drill pad• Fires, tank ruptures• Pit and tank leakage• Flowback transportation-truck

accidents, pipeline failures


EXPOSURE PATHWAYSA. JUDGING BY THE PRESS, YOU MIGHT THINK THAT THE PRIMARY RISK INVOLVES MIGRATION OF FRAC FLUID TO A DOMESTIC AQUIFER.

B. SHALLOW AQUIFER CONTAMINATION FROM BAD CASING IS MORE LIKELY TO OCCUR.

maybe

doubtful

A

B


Shallow Aquifer

Domestic well ~30 m

Well site spills and pit leakage

Flowback pit

Spring

Well

MOST LIKELY HUMAN/ENVIRONMENTAL EXPOSURE PATHWAYS

Pit or well site leakage could appear in a domestic well, a spring or a stream

Casing/cement failure

Volatile organics


Protective measures: Polymer liner across drill pad will be covered with gravel. Containment around tanks


MSEEL ENVIRONMENTAL STUDY

Background

• Funding: USDOE/NETL, Northeast Natural Energy Inc.

• WVU prime, OSU sub• Begin April 2015• Two wells installed in 2010• Project will study two new

horizontal wells• Test bed for new

technologies

Environmental objectives

• Reduce environmental uncertainty and improve environmental performance

• Characterize:– Air emissions– Liquid and Solid wastes

• Organic• Inorganic• Radiologicals


RECOMMENDATIONS: REDUCING ACCIDENTAL RELEASES OF FPW

• Recycle/reuse flowback and produced water for frac water makeup• On site containment:

– Production casing integrity-testing prior to well completion– Drill pad-lined and bermed– Pits-construction/design/inspection according to State standards– Flowback lines to be properly installed/protected

• Transportation:– Tracking and accountability

• Solid waste characterization and disposal according to protective standards (RCRA?)


FOR MORE INFORMATION PLEASE CONTACT:

Paul Ziemkiewicz, DirectorWVU Water Research Institute304 293 [email protected]

mailto:[email protected]

liquid and solid waste streams in appalachian basin unconventional gas by paul ziemkiewicz, phd

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