Produced Formation Water SampleResults from Shale PlaysNancy Pees Coleman, Ph.D.Oklahoma City OklahomaOklahoma City,OklahomaProduced Formation Water ReviewConducted a review of the analyticalresultsof non-potableproducedesults of nonle producedformation water from four shale playsMarcellusBarnettFayettevilleHaynesvilleUtilized several available data sourcesGas Technology Institute Study for theMarcellusUSGS databaseAdditional privately generated data sources2Purpose of the Data ReviewIdentify sentinel parameters to be included in baselinepotable water sampling programCriteria for selection of sentinel parameters was based onpotential mobilityingroundwatersystems,toxicity,andthet a ob ty g ou d ate syste s, to c ty, a d t eability to accurately quantitate the parameters in producedformation waterIdentify parameters which could be released from hostrockSupport decision making ondisposal and treatment andreuse/recycling related to produced water3Shale Play Data EvaluatedSource water for hydraulic fracturing fluidsMixed hydraulic fracturing fluidsProduced formation water from operating wellsProduced formation water after hydraulic fracturing activitiesI i l iIterativesamplesovertimeVarying 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 fracturingAnalytical results available for the following parameters:Volatile organics, including glycolsSemi-volatile organicsMetals, total and dissolvedGeneral chemistry4Radiochemistry (gross alpha/beta, Radium 226/228, and some additionalisotopic nuclides by gamma spectroscopy)Shale InformationShale Play Barnett Fayetteville Haynesville MarcellusAverage Depth FromSurface(ft)7,400 4,500 11,500 6,750( )Bottom HoleTemperature (F)190 130 320 140Bottom HolePressure (psi)2,900 2,000 10,000 4,000Natural gas producing shale zones are thousands of feet belowthe formations which produce potable water5Sampling and Analytical Challenges forProduced Formation WaterAnalytical data has limitations due to sampling challengesNatural gas is contained under high pressure in specialized equipmentnot designed for producing a high quality environmental sampleSample matrix causes collection problemsI iti l d d t th d f iInitialproducedwaterpressuresarethousandsofpsiTemperature of produced water 30-70 degrees CelsiusSafety issues for sampling personnelAnalytical data has limitations due to analytical challengesOrganic chemistry analyses has fewer issuesInorganic and Wet Chemistry tests were affected by very high solidscontent and other matrix complexitiesRadiochemistry affected by solids and barium6Glycols in Produced Formation WaterData available for ethylene glycol and 1,2-propylene glycolData is inconclusive with regards for use as a sentinel compoundDetected values ranged from 12,000 to 87,400 μg/LDetected in 14 of 34 samplesResults for all formation produced water samples were inconsistent inall shale plays due to issues with the analytical methodAnalytical method: EPA Method No. 8015Insufficiently robust to achieve meaningful detection limits due tosample matrix7Detection limits ranged from 10,000 to 50,000 μg/LVolatile and Semi-Volatile Organics inProduced Formation WaterData was available for produced formation water fromoperating wells and iterative (time series) samples forproduced water following hydraulic fracturing activitiesThe majority of the VOC and SVOC results were belowdetection limits for both sets of samplesB Eth l b T l d X l tBenzene,Ethyl benzene,Tolueneand Xylenesmostconsistently detected VOCs - produced in formationPhenol and Pyridine most consistently detected SVOCsNo consistent trends in VOC or SVOC concentrations with8time in the iterative samplesSummary of Analytical ResultsSelected Volatile Organic CompoundsProduced Formation Water after Hydraulic Fracture (First 30 Days)ConcentrationsinProducedFormationWaterbyShalePlayParameter(μg/L)BarnettFayettevilleHaynesvilleMarcellusBenzene <1– 97 <1– 140 <1‐3,460 <1– 1,950Ethylbenzene <1‐249 <1– 11 <1– 1,470 <1‐164Toluene 1– 578 <1– 117 2.6– 11,400 <1– 3,190Xylenes,total <3– 2,480 <3– 60.1 12– 10,700 <2– 1,970No.ofWellsSampled323 49Summary of Analytical ResultsSelected Volatile Organic CompoundsProduced Formation Water from Operating WellsConcentrationsinProducedFormationWaterbyShalePlayParametery(μg/L)BarnettFayettevilleHaynesvilleMarcellusBenzene 4.37– 1,600 <1– 1.05 76– 3,140 <1‐513Ethylbenzene <1– 102 ND 2.5– 839 <1– 51.6Toluene 8.8– 3,250 ND 84– 11,300 <1‐918Xylenes,total <3– 2,630 <3– 4.86 31– 14,500 <3‐439No.ofWellsSampled15 9 5 1510Summary of Analytical ResultsSelected Semi-Volatile Organic CompoundsProduced Formation Water after Hydraulic Fracture (First 30 days)ConcentrationsinProducedWaterbyShalePlay(μg/L)Parameteryy(μg/ )Barnett Fayetteville Haynesville MarcellusPhenol ND– 1,160 ND ND‐971 ND‐459Pyridine ND–264 ND–534 ND NDNo.ofWellsSampled32 3 411Summary of Analytical ResultsSelected Semi-Volatile Organic CompoundsProduced Formation Water from OperatingWellsgConcentrationsinProducedWaterbyShalePlay(μg/L)Parameteryy(μg/ )Barnett Fayetteville Haynesville MarcellusPhenol 12‐31 ND‐32 250– 3,720 ND‐34Pyridine 12‐758 ND–92 ND–15.5 ND‐56No.ofWellsSampled15 9 5 1512General Chemistry Analytical Results fromProduced Formation WaterTotal Dissolved Solids, Divalent Cations, and Chloride wereelevated in produced formation water samples for all ShaleplaysConcentrations of Barium and Strontium tended tocorrelate with Total Dissolved Solids resultsChloride represents the most abundant anionThe data are generally consistent between the data sourcesThe data are generally consistent with the reported rangesof Total Dissolved Solids in produced formation water fromall types of wells available in the literature13Arsenic Analytical Resultsfor Produced Formation WaterInitial concern due to known potential for interactionsbetween refined hydrocarbon products in groundwater andnaturally-occurring arsenicArsenic concentrations were rarely found to be abovemethod detection limits in the produced formation waterssampledGTI results for Marcellus―Influent water – ND – 9.1μg/L5D d d tND124g/L―-Dayproducedwater––μ―90-day produced water - ND - 114μg/LOther data sources reviewed for the Barnett, Fayetteville andH illll t ti b l th l ti l d t ti li it14Haynesville– allconcentrationsbelowtheanalytical detectionlimitRadionuclides inProduced Formation WaterPresence of radionuclides in produced formation water is well documentedAnalytical method of choice: EPA Method 901 1 modified (GammaAnalytical method of choice: EPA Method 901.1 modified (GammaSpectroscopy)Less influenced by matrix interferencesData must be reported with activity, accompanied by standard deviation andminimum detected concentrationExample: 970±130 pCi/L (MDC 30 pCi/L) Radium-226Necessary to put data result into context, particularly for non-detectedvalues. Unless data is presented in this format, it is meaningless.Focus should be on Radium-226, Radium-228, and Uranium-238Radium 226 and radium 228 represent more than 80% of the potentialradiation dose in ingested water15ConclusionsProduced formation waters are highly variable within and between shaleformationsAnalytical techniques must be robustto the matrix interferences from TDSMost reliable sentinel compounds are TDS, chloride and divalent cationsFew VOCs and SVOCs are consistently found in produced formation water.Benzene, ethyl benzene, toluene andxylenes are the most frequently detectedVOCs and are naturally occurringThe concentrations of VOCs and SVOCs in produced formation water aregenerally too low for use as sentinel compounds16