Produced Formation Water Sample

Results from Shale Pla

y

s

Nancy Pees ColemanOklahoma City OklaOklahoma City, Okla
Produced Formation Water Review

Conducted a review of the anresults of non esults

of n

o

n

-potable produ

le

p

rodu

formation water from four sh

MarcellusBarnettFayettevilleHaynesville

Utilized several available dat

Gas Technology Institute StudMarcellusUSGS databaseAdditional privately generated 
Purpose of the Data Review

Identify sentinel parameters to be included in basepotable water sampling program

Criteria for selection of sentinel parameters was baspote t a ob ty g ou d ate syste s, to c ty, a 

n

tial mobility in 

g

rou

n

d

water syste

ms, toxi

city,

a

ability to accurately quantitate the parameters in proformation water

Identify parameters which could be released from rockSupport decision making on disposal and treatmenreuse/recycling related to produced water
Shale Play Data Evaluated

Source water for hydraulic fracturing fluidsMixed hydraulic fracturing fluidsProduced formation water from operating wellsProduced formation water after hydraulic fracturing activ

I i l i Iterative samples over

time

Varying sampling times utilized by different data sources

― GTI Study in Marcellus – samples up to 90 days after hydraulic fracturing― Additional Data 

– samples up to 30 days after hydraulic fracturing

Analytical results available for the following parameters:

Volatile organics, including glycols Semi-volatile organicsMetals, total and dissolvedGeneral chemistryRadiochemistry (gross alpha/beta, Radium 226/228, and some isotopic nuclides by gamma spectroscopy)
Shale Information

Shale Play Barnett Fayetteville Haynesville 

Average Depth From 

Surface (ft)

7,400 4,500 11,500 

( )

Bottom Hole 

Temperature (F)

190 130 320 

Bottom Hole 

Pressure (psi)

2,900 2,000 10,000 

 Natural gas producing shale zones are thousands of feet 

the formations which produce potable water
Sampling and Analytical Challenges f

Produced Formation Water

Analytical data has limitations due to sampling chal

Natural gas is contained under high pressure in specialized not designed for producing a high quality environmental saSample matrix causes collection problemsI iti l d d t th d f i Initi

al pro

duced wa

ter pressures are thousan

d

s

of psi

Temperature of produced water 30-70 degrees CelsiusSafety issues for sampling personnel

Analytical data has limitations due to analytical chal

Organic chemistry analyses has fewer issuesInorganic and Wet Chemistry tests were affected by very higcontent and other matrix complexitiesRadiochemistry affected by solids and barium
Glycols in Produced Formation Water

Data available for ethylene glycol and 1,2-propylene glycolData is inconclusive with regards for use as a sentinel compo

Detected values ranged from 12,000 to 87,400 μg/L Detected in 14 of 34 samples

Results for all formation produced water samples were inconall shale plays due to issues with the analytical methodAnalytical method: EPA Method No. 8015

Insufficiently robust to achieve meaningful detection limsample matrixDetection limits ranged from 10,000 to 50,000 μg/L
Volatile and Semi-Volatile Organics in 

Produced Formation Water 

Data was available for produced formation water foperating wells and iterative (time series) samples produced water following hydraulic fracturing activThe majority of the VOC and SVOC results were bedetection limits for both sets of samplesB Eth l b T l d X l Benzene, Eth

yl benzene, Toluene and Xylenes mos

consistently detected VOCs - produced in formatioPhenol and Pyridine most consistently detected SVNo consistent trends in VOC or SVOC concentrationtime in the iterative samples 
Summary of Analytical Results

Selected Volatile Organic CompoundsProduced Formation Water after Hydraulic Fracture (First 30 Days)

Concentrations in Produced Formation Water by 

Parameter

(μg/L)

Barnett Fayetteville Haynesville 

Benzene <

1 – 97 <1 – 140 <1 ‐3,460 

Ethyl benzene <1 ‐ 249 <1 – 11 <1 – 1,470 

Toluene 1 – 578 <1 – 117 2.6 – 11,400 

Xylenes, total <3 – 2,480 <3 – 60.1 12 – 10,700 

No. of Wells

Sampled

3 23 
Summary of Analytical Results

Selected Volatile Organic CompoundsProduced Formation Water from Operating Wells

Concentrations in Produced Formation Water

b

y 

Parameter

y

(μg/L)

Barnett Fayetteville Haynesville 

Benzene 4.37 – 1,600 <1 – 1.05 76 – 3,140 

Ethyl benzene <1 – 102 ND 2.5 – 839 

Toluene 8.8 – 3,250 ND 84 – 11, 300 

Xylenes, total <3 – 2,630 <3 – 4.86 31 – 14,500 

No. of Wells

Sampled 15 9 5 
Summary of Analytical Results

Selected Semi-Volatile Organic CompoundsProduced Formation Water after Hydraulic Fracture (First 30 days)

Concentrations in Produced Water

b

y Shale P

Parameter

y

Barnett Fayetteville Haynesville 

Phenol ND – 1,160 ND ND ‐ 971 

Pyridine ND

– 264 ND

– 534 ND 

No. of WellsSampled 32 3 
Summary of Analytical Results

Selected Semi-Volatile Organic CompoundsProduced Formation Water from O

p g eratin

g Wells

Concentrations in Produced Water

b

y Shale P

Parameter

y

Barnett Fayetteville Haynesville 

Phenol 12 ‐ 31 ND ‐ 32 250 – 3,720 

Pyridine 12 ‐ 758 ND

– 92 ND

– 15.5 

No. of Wells

Sampled 15 9 5 
General Chemistry Analytical Results from 

Produced Formation Water

Total Dissolved Solids, Divalent Cations, and Chlorielevated in produced formation water samples for playsConcentrations of Barium and Strontium tended to correlate with Total Dissolved Solids resultsChloride represents the most abundant anionThe data are generally consistent between the datThe data are generally consistent with the reported of Total Dissolved Solids in produced formation waall types of wells available in the literature
Arsenic Analytical Results

for Produced Formation Water

Initial concern due to known potential for interactiobetween refined hydrocarbon products in groundwanaturally-occurring arsenicArsenic concentrations were rarely found to be abomethod detection limits in the produced formation sampled

GTI results for Marcellus

― Influent water – ND – 9.1 

μg/L 

―

5-D d d t Day pro

duced water

– ND 

– 124 

μg/L

― 90-day produced water - ND - 114 

μg/L

Other data sources reviewed for the Barnett, Fayetteville aH ill ll t ti b l th l ti l d t Haynesvill

e – all concen

trations b

elow th

e analytical d

e

te
Radionuclides in 

Produced Formation Water

Presence of radionuclides in produced formation water is well dAnalytical method of choice: EP Analytical method of choice: EPA Method 901 A Method 901 1 modified (Gam

.1 modified (Gam

Spectroscopy)

Less influenced by matrix interferences

Data must be reported with activity, accompanied by standard minimum detected concentration 

Example: 970 ± 130 pCi/L (MDC 30 pCi/L) Radium-226Necessary to put data result into context, particularly for novalues. Unless data is presented in this format, it is meanin

Focus should be on Radium-226, Radium-228, and Uranium-23

Radium 226 and radium 228 represent more than 80% of tradiation dose in ingested water
Conclusions

Produced formation waters are highly variable within and between formationsAnalytical techniques must be robust to the matrix interferences froMost reliable sentinel compounds are TDS, chloride and divalent caFew VOCs and SVOCs are consistently found in produced formation Benzene, ethyl benzene, toluene and xylenes are the most frequent

VOCs and are naturally occurring

The concentrations of VOCs and SVOCs in produced formation wategenerally too low for use as sentinel compounds