Historic Oilfield Arsenic Sources and Historic Oilfield Arsenic Sources and Pit Groundwater Models: an Example Pit Groundwater Models: an Example from Lake St. John Field, LA from Lake St. John Field, LA Mary L. Barrett, Ph.D. Mary L. Barrett, Ph.D. Consulting Geologist & Oilfield Historian Consulting Geologist & Oilfield Historian Shreveport, LA Shreveport, LA [email protected][email protected]65 65 th th Convention, Gulf Coast Assoc. of Geol. Societies Convention, Gulf Coast Assoc. of Geol. Societies September 20 September 20- 22, 2015 22, 2015 --- --- Houston, TX Houston, TX
Transcript
Historic Oilfield Arsenic Sources andHistoric Oilfield Arsenic Sources andPit Groundwater Models: an ExamplePit Groundwater Models: an Example
from Lake St. John Field, LAfrom Lake St. John Field, LA
Mary L. Barrett, Ph.D.Mary L. Barrett, Ph.D.Consulting Geologist & Oilfield HistorianConsulting Geologist & Oilfield Historian
6565thth Convention, Gulf Coast Assoc. of Geol. SocietiesConvention, Gulf Coast Assoc. of Geol. SocietiesSeptember 20September 20--22, 201522, 2015------Houston, TXHouston, TX
Presentation ObjectivesPresentation Objectives
Consider multiple hypotheses for origin ofConsider multiple hypotheses for origin ofelevated groundwater (gw) arsenic (As),elevated groundwater (gw) arsenic (As),iron (Fe) and chlorides (Cl) at legacyiron (Fe) and chlorides (Cl) at legacyoilfield sitesoilfield sites
Consider whether data (as of 4/15)Consider whether data (as of 4/15)reasonably support a 2008 reductivereasonably support a 2008 reductive--dissolution GW model for elevated arsenicdissolution GW model for elevated arsenicpatterns on two leases at Lake St. Johnpatterns on two leases at Lake St. JohnField, Concordia Parish, LAField, Concordia Parish, LA
Public Record Usage for InterpretationsPublic Record Usage for Interpretations
The example from LSJ Field, LA, has a large public recordThe example from LSJ Field, LA, has a large public recordavailable due to litigation (court records in one case) andavailable due to litigation (court records in one case) andespecially due to LA Act 312 (2006+) & LA Office ofespecially due to LA Act 312 (2006+) & LA Office ofConservation (OOC) oversight of oilfield cleanup of allConservation (OOC) oversight of oilfield cleanup of alloilfield litigationoilfield litigation ““legacylegacy”” sites (reports, raw data; hearingsites (reports, raw data; hearingrecordsrecords……))
I was a defense expert retained in the two cases thatI was a defense expert retained in the two cases thatgenerated public records above; geologist, oilfieldgenerated public records above; geologist, oilfieldhistorian (environmental companies responsible forhistorian (environmental companies responsible foranalytical data: ICON; Pisani & Assoc., some Geosyntec)analytical data: ICON; Pisani & Assoc., some Geosyntec)
Work on the last case ended Feb. 2014; I have pursuedWork on the last case ended Feb. 2014; I have pursuedthis research since then, not retained concerning it, nothis research since then, not retained concerning it, nodiscussions with past litigation experts (my opinions)discussions with past litigation experts (my opinions)
Study AreaStudy Area
(Modified from Pisani report, 2008;LA OOC file # 006-007)
Lake St. John Field ExampleLake St. John Field Example
Discovered in 1942, Tensas & ConcordiaDiscovered in 1942, Tensas & ConcordiaParishes, LAParishes, LA
Major producing field for The CaliforniaMajor producing field for The CaliforniaCompany (Standard Oil of CA, later Chevron)Company (Standard Oil of CA, later Chevron)
Both unit (Cretaceous & some Tertiary age) &Both unit (Cretaceous & some Tertiary age) &lease productionlease production (Wilcox Fm mainly)(Wilcox Fm mainly)
Outline of field studyOutline of field study–– Public records indicate 1950s arsenic inhibitor usePublic records indicate 1950s arsenic inhibitor use
–– Modern shallow groundwater geochemistry around leaseModern shallow groundwater geochemistry around lease
emergency pit usage areas documents its impactemergency pit usage areas documents its impact
Reductive Dissolution of Iron Oxides:Reductive Dissolution of Iron Oxides:The Basic ModelThe Basic Model
AnAn equilibriumequilibrium diagram fordiagram forsystem Assystem As--OO22--HH22OOIron oxides common in our LAIron oxides common in our LAsedimentsedimentAs bound to iron oxides,As bound to iron oxides,released into GW withreleased into GW with““reductive dissolutionreductive dissolution”” whenwhensome cause for a reducingsome cause for a reducingenvironment (organics, oil,environment (organics, oil,clayclay……))Iron oxides reIron oxides re--precipitate asprecipitate asGW move into oxidizing zone,GW move into oxidizing zone,also locks up Asalso locks up AsDoes not address AsDoes not address Asdesorption (phosphates)desorption (phosphates)Model looks for relationsModel looks for relationsbetween ORP, Fe, Asbetween ORP, Fe, As
IssuesIssues
Arsenic models are useful, but they areArsenic models are useful, but they areextrapolated to Gulf Coast oilfield regions ofextrapolated to Gulf Coast oilfield regions ofdifferent geology & hydrogeology, and the modeldifferent geology & hydrogeology, and the modeldoes not consider impacts fromdoes not consider impacts from ““oilfieldoilfieldchemistrychemistry”” and anthropogenic activitiesand anthropogenic activities
WasteWaste ““oilfield chemistryoilfield chemistry”” has a history, & pitshas a history, & pitsoften record this historyoften record this history
Any oilfield groundwater model which calls onAny oilfield groundwater model which calls onnaturallynaturally--dissolved iron & arsenic must considerdissolved iron & arsenic must consideranthropogenic sources in these old oil fieldsanthropogenic sources in these old oil fields(and any industrial site, for that matter)(and any industrial site, for that matter)
Amorphous Iron Precipitates: Long History of Study inAmorphous Iron Precipitates: Long History of Study inOilfield Chemistry (Hydrous ferric oxidesOilfield Chemistry (Hydrous ferric oxides——HFOs)HFOs)
1950s Oilfield Water Treatment (Powell & Johnson, 1952)
Iron Analyses, LSJ Field Produced WaterIron Analyses, LSJ Field Produced Water
Anthropogenic Arsenic in OilfieldsAnthropogenic Arsenic in OilfieldsContinued (cow studies)Continued (cow studies)
Veterinary journals document the presence ofVeterinary journals document the presence ofanthropogenic arsenic used around oilfieldanthropogenic arsenic used around oilfieldfacilitiesfacilities
Recognized around pits, tanks and flowlinesRecognized around pits, tanks and flowlines
Past usages in oil fieldsPast usages in oil fields
–– asas ““rust inhibitor and herbiciderust inhibitor and herbicide”” (Coppock & others,(Coppock & others,1996)1996)
–– 19571957, LA Stream Control, LA Stream ControlCommission minutes reportCommission minutes reportphasephase--out of oilfield arsenicout of oilfield arseniccorrosion pellets, strippercorrosion pellets, stripperfieldsfields
–– 19601960, general end of U. S., general end of U. S.oilfield arsenic corrosionoilfield arsenic corrosioninhibitors (Gardner, 1960);inhibitors (Gardner, 1960);move to organicsmove to organics
Iron & 1950s Arsenic Inhibitor in ProducedIron & 1950s Arsenic Inhibitor in ProducedWater (Wilcox Trend, Texas)Water (Wilcox Trend, Texas)
Jones (1955)(Jones, 1955)
LSJ Field Public Documents, ArsenicLSJ Field Public Documents, ArsenicCorrosion InhibitorsCorrosion Inhibitors
(LA OOC Tensas Poppadoc hearing, 2009; Miller/ICONreliance documents, v. 28;Tensas/Miller 02469-02470)
WW--41 History41 History
WW--41, an arsenic corrosion inhibitor patented by41, an arsenic corrosion inhibitor patented byStandard Oil of CA, is one example of arsenicStandard Oil of CA, is one example of arseniccorrosion inhibitors used in some 1950s oilfields ofcorrosion inhibitors used in some 1950s oilfields ofthe U.S.the U.S.
Its history is available in public documents.Its history is available in public documents.
WW--41 History41 History
California ResearchCalifornia ResearchCorpCorp (As & oilfield corrosion)(As & oilfield corrosion)
–– Dec 1950, 2 patents,Dec 1950, 2 patents,Rohrback et al (1954)Rohrback et al (1954)
–– Mar 1951, 2 patents,Mar 1951, 2 patents,
Rohrback et al (1953)Rohrback et al (1953)
–– Dec 1951, patent,Dec 1951, patent,
Rohrback et al (1953)Rohrback et al (1953)
–– Oct 1954, patent,Oct 1954, patent,
Frisius (1959)Frisius (1959)
California SprayCalifornia Spray--Chemical CorpChemical Corp
–– 1952, Patent application1952, Patent applicationgranted in 1953 forgranted in 1953 for ““OrthoOrthoWW--41,41,”” also used isalso used is ““WW--41,41,”” for arsenic corrosionfor arsenic corrosioninhibitor (42 % sodiuminhibitor (42 % sodiumarsenite) (EPA, 1973)arsenite) (EPA, 1973)
(My Opinion from the public record: W-41 was used in the LSJ Fieldin the 1950s; organic inhibitors were used after that)
LSJ Field Study Area: Lease Tank BatteryLSJ Field Study Area: Lease Tank Batteryand SWD Emergency Pitsand SWD Emergency Pits
Mississippi RiverMississippi RiverAlluvium & Aquifer atAlluvium & Aquifer at
LSJ FieldLSJ Field
–– Braided stream gravels atBraided stream gravels atbase; cuts into underlyingbase; cuts into underlyingCatahoula Fm sandsCatahoula Fm sands
–– Mostly pointMostly point--bar sandsbar sands
–– FiningFining--up into levee,up into levee,overbank, floodplainoverbank, floodplaindeposits (clay/silt)deposits (clay/silt)
–– This nearThis near--surface unit issurface unit isaquiferaquifer’’s confining layers confining layer
(Typical near-surfacesection from Pisani,2008; LA OOC file #006-007)
Pan American Pit (closed ~ 1984)Pan American Pit (closed ~ 1984)–– 150150’’ x 200x 200’’ x 8x 8’’ (include 2(include 2’’ levee)levee)
–– UsageUsage ““only in emergencyonly in emergency””
(LA OOC Tensas-Poppadoc hearing; exhibit Tensas/Miller 2455-56)
FineFine--grained Unit Thicknessgrained Unit Thickness
(data from all soil boring descriptions of ICON, Pisani and Geosyntec;Meander & swale lines after Saucier, 1967)
Shallow Groundwater Data (8Shallow Groundwater Data (8’’ to 22to 22’’below surface) Used in This Talkbelow surface) Used in This Talk
The analyses from Pisani & Associates, ICONThe analyses from Pisani & Associates, ICON(G. Miller), are numerous and of high(G. Miller), are numerous and of high--qualityquality(Geosyntec data are limited but of high(Geosyntec data are limited but of high--quality)quality)
Shallow groundwater data are most reflective ofShallow groundwater data are most reflective ofold oilfield impacts & possible controllingold oilfield impacts & possible controllinginfluences in pit areasinfluences in pit areas
Groundwater wells at deeper depths (60Groundwater wells at deeper depths (60’’--8080’’, +, +below surface) do not have arsenic valuesbelow surface) do not have arsenic valuesabove natural variability range; deeper alluviumabove natural variability range; deeper alluviumwaters are a variation within the largerwaters are a variation within the largersediment/water geochemical systemsediment/water geochemical system
What is the LSJ Field AreaWhat is the LSJ Field Area’’s Dissolveds DissolvedArsenic Natural Variability?Arsenic Natural Variability?
Pisani & Associates (2012 report; LA OOC filePisani & Associates (2012 report; LA OOC file# 007# 007--007) interpret the natural range from non007) interpret the natural range from non--detectdetect(ND) up to 0.12 mg/l(ND) up to 0.12 mg/lA study in shallow allluvium across the River in MississippiA study in shallow allluvium across the River in Mississippihas an As range of ND to 0.10 mg/l (Welsh et al, 2010;has an As range of ND to 0.10 mg/l (Welsh et al, 2010;also phosphorous)also phosphorous)ICON data from Tensas Parish landfill, ND up to 0.16 mg/lICON data from Tensas Parish landfill, ND up to 0.16 mg/l(~ 25 mi away, 1994 to 2014 data, LDEQ EDMS # AI(~ 25 mi away, 1994 to 2014 data, LDEQ EDMS # AI43506)43506)The LSJ field study area has localized shallowThe LSJ field study area has localized shallowgroundwater measurements above these valuesgroundwater measurements above these valuesLimited arsenic species measurements at LSJ field; bothLimited arsenic species measurements at LSJ field; botharsenic species were present (AsIII and AsV) in similararsenic species were present (AsIII and AsV) in similaramountsamounts
Arsenic in Pit Soils, Sediment, & WatersArsenic in Pit Soils, Sediment, & Waters
55 years after alleged As usage, the pit solids of today55 years after alleged As usage, the pit solids of todayhave arsenic ranges within Parish soil rangeshave arsenic ranges within Parish soil ranges–– Pits modified, rebuilt 2Pits modified, rebuilt 2--3 times during usage3 times during usage
–– Pan Am & Applegate pit closure ~1984; both rePan Am & Applegate pit closure ~1984; both re--closedclosed(Applegate 2007; Pan Am 2010); Wilcox pit closed in 1990(Applegate 2007; Pan Am 2010); Wilcox pit closed in 1990
–– As analyzed in soils/sediment range from 1 to 10 mg/kg; oneAs analyzed in soils/sediment range from 1 to 10 mg/kg; one(Deuel,1987) Wilcox pit sample at 16.9(Deuel,1987) Wilcox pit sample at 16.9
A 1984 G & E study found elevated arsenic in ApplegateA 1984 G & E study found elevated arsenic in Applegate(0.04 mg/l) and Pan Am (0.05 mg/l) pit surface waters.(0.04 mg/l) and Pan Am (0.05 mg/l) pit surface waters.The 2 ft of bottom sludge ranged from 3 to 4.5 mg/kg AsThe 2 ft of bottom sludge ranged from 3 to 4.5 mg/kg As
–– Sampled during high GWSampled during high GWelevation, high river stage,elevation, high river stage,reverse GW movementreverse GW movementtowards the laketowards the lake
–– Apparent As relationshipsApparent As relationshipswith ORP, Fewith ORP, Fe
–– Apparent relationship ofApparent relationship ofORP and conductivityORP and conductivity
(salinity) ?(salinity) ?
Applegate Pit Area, GW Data Ranges (inApplegate Pit Area, GW Data Ranges (inmg/l) from 2008mg/l) from 2008--20152015
Data from OOC Poppadoc file # 006-007; Geosyntec Report, 2008, Pisani 2012-2015
–– The 2008 data areThe 2008 data aregenerally lower valuesgenerally lower valuescompared to 2007 andcompared to 2007 and20122012--1515
–– The April 2008 samplingThe April 2008 samplingwas 6 months after pit rewas 6 months after pit re--closure & during high GWclosure & during high GWand river elevations (GWand river elevations (GWflow away from river)flow away from river)
–– MWMW--3 has elevated Fe,3 has elevated Fe,why?why?
Interpretation of PatternsInterpretation of Patterns
GW under the Pan Am pit moderately reduced, but no clearGW under the Pan Am pit moderately reduced, but no clearrelation of ORP & Asrelation of ORP & AsAreas of oily waste impacts do not always have elevated AsAreas of oily waste impacts do not always have elevated AsHighest Fe values (interpreted as added) have elevatedHighest Fe values (interpreted as added) have elevatedarsenic, and associated Cl indicate oilfield impactsarsenic, and associated Cl indicate oilfield impactsOther Fe sources besides soil available (produced water,Other Fe sources besides soil available (produced water,rusty old flowlines, etc)rusty old flowlines, etc)Arsenic corrosion inhibitor usage in the 1950s likely source ofArsenic corrosion inhibitor usage in the 1950s likely source ofelevated dissolved arsenic in pits at LSJ fieldelevated dissolved arsenic in pits at LSJ fieldIn addition, arsenicIn addition, arsenic--based herbicides & rust inhibitors possiblybased herbicides & rust inhibitors possiblyused in the past around oilfield facilitiesused in the past around oilfield facilities——this usage and itsthis usage and itsmodern impacts usually not consideredmodern impacts usually not consideredThe Geosyntec 2008 interpretation of a reductiveThe Geosyntec 2008 interpretation of a reductive--dissolutiondissolutionmodel to explain elevated GW arsenic & iron is not supportedmodel to explain elevated GW arsenic & iron is not supportedby the additional data; plus, no followby the additional data; plus, no follow--up ORP data acquired,up ORP data acquired,Fe measurements ended 2014Fe measurements ended 2014
A Possible ModelA Possible Model
Observed ion mobility in GW from PA pit: Cl > Fe > AsObserved ion mobility in GW from PA pit: Cl > Fe > AsHFOs added to emergency pits from produced waterHFOs added to emergency pits from produced waterover decades; As usage in 1950s, strongly absorbed byover decades; As usage in 1950s, strongly absorbed byHFOs when presentHFOs when presentIn pit bottom, oily sludge and sometimes stagnantIn pit bottom, oily sludge and sometimes stagnantsaltwater above this, reducing; GW below reducingsaltwater above this, reducing; GW below reducingMovement of reducing water with Cl, Fe (Movement of reducing water with Cl, Fe (++ As) where pitAs) where pitseepage, into sediment with Fe grain coatingsseepage, into sediment with Fe grain coatingsGW away from pit more oxidizing, see Fe frontGW away from pit more oxidizing, see Fe frontAdded As stays within or close to pit or source originsAdded As stays within or close to pit or source originsOne monitor well (MWOne monitor well (MW--3) in Applegate area has elevated3) in Applegate area has elevatedFe (and possibly As) that is not related to the pit; the FeFe (and possibly As) that is not related to the pit; the Feis a potential clue that another anthropogenic source isis a potential clue that another anthropogenic source isresponsibleresponsible
ConclusionsConclusions
The geochemistry of pit impacts and signaturesThe geochemistry of pit impacts and signaturesis greatly enhanced by historic knowledgeis greatly enhanced by historic knowledgeArsenic GW models for oilfield pits may beArsenic GW models for oilfield pits may beuseful, but oilfield chemistry & past pit functionsuseful, but oilfield chemistry & past pit functionswill strongly modify generic modelswill strongly modify generic modelsA reductive dissolution model for elevatedA reductive dissolution model for elevatedarsenic and iron below oilfield pits must considerarsenic and iron below oilfield pits must considerall anthropogenic sources to be viableall anthropogenic sources to be viableChlorides are an important marker forChlorides are an important marker forrecognizing oilfield impact boundariesrecognizing oilfield impact boundariesElevated iron and its spatial oilfield patterns mayElevated iron and its spatial oilfield patterns maygive additional clues for understanding elevatedgive additional clues for understanding elevatedGW arsenicGW arsenic
