Table Of Content

1.12 Fossil Fuels Ilhami Yildiz, Dalhousie University,Halifax, NS,Canada r2018ElsevierInc.Allrightsreserved. 1.12.1 Introduction 521 1.12.1.1 Global EnergySource andDemand 522 1.12.1.2 FossilFuel 522 1.12.1.3 Hubbert PeakTheory 524 1.12.2 Oil 526 1.12.2.1 Sources ofOil 526 1.12.2.1.1 Conventional sources 526 1.12.2.1.2 Unconventional sources 526 1.12.2.2 OilReserves 527 1.12.2.2.1 Reservesof unconventional oil 528 1.12.2.3 OilProduction, Demand andTrade 530 1.12.2.4 Peak Oil 534 1.12.2.5 Environmental Impactsof Oil 535 1.12.2.5.1 Case Study:Oil sandsproduction inAlberta, Canada 536 1.12.3 NaturalGas 536 1.12.3.1 Sources ofNatural Gas 537 1.12.3.2 Natural Gas Reserves 537 1.12.3.3 Natural Gas Production,Demand,andTrade 539 1.12.3.4 Peak Gas 542 1.12.3.5 Environmental Impactsof Natural Gas 544 1.12.4 Coal 545 1.12.4.1 Sources ofCoal 545 1.12.4.2 Coal Reserves 546 1.12.4.3 Coal Production,Demand, andTrade 547 1.12.4.4 Peak Coal 550 1.12.4.5 Environmental Impactsof Coal 551 1.12.4.5.1 Case Study:coalmining in China 552 1.12.5 Further CaseStudies 552 1.12.5.1 Case Study:Global FossilFuel Consumption andSupply 552 1.12.5.2 Case Study:Fossil FuelConsumption andSupplyin Africa 553 1.12.5.3 Case Study:Fossil FuelConsumption andSupplyin NorthAmerica 553 1.12.5.4 Case Study:Fossil FuelConsumption andSupplyin theUnites States 553 1.12.5.5 Case Study:Fossil FuelConsumption andSupplyin Brazil 554 1.12.5.6 Case Study:Fossil FuelConsumption andSupplyin theEuropean Union 555 1.12.5.7 Case Study:Fossil FuelConsumption andSupplyin theMiddle East 555 1.12.5.8 Case Study:Fossil FuelConsumption andSupplyin RussianFederation 556 1.12.5.9 Case Study:Fossil FuelConsumption andSupplyin India 557 1.12.5.10 Case Study:Fossil FuelConsumption andSupplyin OtherEmerging Asia 558 1.12.6 Future Prospects 558 1.12.6.1 Oil 558 1.12.6.2 Natural Gas 559 1.12.6.3 Coal 560 1.12.7 ConcludingRemarks 561 1.12.7.1 Oil 561 1.12.7.2 Natural Gas 562 1.12.7.3 Coal 562 References 563 Further Reading 567 RelevantWebsites 567 ComprehensiveEnergySystems,Volume1 doi:10.1016/B978-0-12-809597-3.00111-5 521 522 Fossil Fuels 1.12.1 Introduction Fossil fuelshave always hadthe majorshare in the global primary energyconsumption.Even though the share of fossil fuel consumptionhasdecreasedinrecentyearsandispredictedtodecreasefurther,theywillcontinuetoholdthemajorshareinthe primaryenergymixintheforeseeablefutureasmoreunconventionalfossilfuelsareexplored.Overallfossilfuelconsumption increasedapproximately51%intheperiodof1995–2015,anditispredictedthattheconsumptionwillincreaseapproximately 18%moreintheperiodof2015–35.Thefollowingsectionsofthischapteroverviewthepast,current,andfuturedevelopments of fossil fuels, including oil, natural gas, and coal with their reserves, productions, consumptions, peaks and environmental impacts. 1.12.1.1 GlobalEnergySource andDemand EnergysupportsallformsoflifeonEarth,andisdirectlyacquiredfromsunlightbyphotosyntheticorganisms,includingplantsand microorganisms.Thisnaturalenergysourceistransmitted,converted,andreleasedthroughthelivingtissuesandfoodchain[1].The mostprimitiveformsofenergy,suchasoil,naturalgas,andcoal,areproducedandaccumulatedunderneaththeearthduetonatural processesinthepastmillionsofyears.Thesenonrenewablefossilfuelresources,whichhavetremendousvalueforusnowandfor ourfuturegenerations,areexpectedtobedepletedduetotheworldpopulationgrowthandindustrialdevelopment[1,2].Withthe emergenceanddevelopmentofindustrialandagriculturalactivities,numerousproducts,includingplastics,textiles,fertilizers,and productsfromsteelmanufacturingandpetrochemicalindustry,havebeengeneratedtomeetourdailyneeds.Aslargerandmore industrialplantsarebuilt,obviouslymoreenergyisrequiredforoperation,processing,andtransportation[3].Theworldpopulation isincreasingrapidly,especiallyinthedevelopingcountries,withanapproximately80millionmoreadditioneveryyear[4].People’s lifestyleshavebeenchanginggradually,particularlyinthedevelopedcountries,andthedevelopingnationsarefollowingthetrend. Energymakesworkandlifemoreconvenientandefficient.Therisingpopulationanddemandforconvenientlifestyleswillrequire more goods and therefore more energy resources. Considering the imbalance between supply and demand due to depletion of nonrenewable energy resources might eventually trigger an energy crisis, open and undercover conflicts from an international perspectivehavealreadystartedtotakeplace.Therefore,renewableenergyexploitationandenergyefficiencyimprovementarecritical themesforsustainableenergysupply,aswellasplayanessentialroleincontinuouslyprovidingadecentlivingstandardforhuman beings [1]. In the years between 1973 and 2010, the global energy consumption grew by 186% and supply for industrial use increasedby157%[2,5,6].Currently,theworldenergysourcesareprimarilycontributedbyfossilfuels,hydropower,nuclearenergy, windenergy,solarenergy,andotherrenewables(seeFig.1).AndtheInternationalEnergyOutlook2016projectsremarkablegrowth inworldwideenergyconsumptionindifferentregionsovertheperiodof2012–40(seeTable1). TheWorldEnergyCouncil(WEC)andInternationalEnergyAgency(IEA)reportedthattheworldenergydemandin2020is expectedtoriseby50%to80%fromthe1990sandthenumberisprojectedtoincreasebymorethanone-thirdbytheyear2035 onthebasisofthepresentlevel.Itshouldbenotedthatapproximately60%ofthegrowthindemandwillmainlycomefrom China, India, and the Middle East [2,7,8]. The global energy demand from all sources is expected to expand, including oil (13%), coal (17%), natural gas (48%), nuclear (66%), and renewables (77%) [9]. Global electricity demand as well is fore- castedtoincreaseby70%bytheyear2030[10].Therenewableenergycontribution,includinghydropower,geothermal,and solar, is expected to reach 30% of total electricity supply by 2035 [10]. However, thermal electricity generation using coal, naturalgasandnuclearwillstillserveforpowergenerationaroundtheworld,andcoalwillcontinuetodominatehavingthe largestshare[11]. Overthepasttwodecades,hundredsofmillionsofpeoplelivingindevelopingcountries,particularlyinChinaandIndia, have gained access to modern energy services due to their quickly growing urbanization and economic development [3]. However,therewerestill1.3billionpeoplewhodidnothaveanyshareintheuseofelectricitygeneratedintheyear2010,and approximately 2.6 billion people still relied on traditional biomass energy, such as wood and other forms of biomass, for cooking and heating purposes [9,12]. Moreover, Global Energy Assessment (GEA) stated that about nine billion people are projectedtorequireaffordableenergyservicesbytheyear2050[13].Therenewableenergyhasrecentlyexperiencedexponential growthintheshareoftheenergymarkets;however,itstillaccountsforonlyasmallportionoftotalprimaryenergysupply,and theircontributionisnotlikelytohaveenormousimpactsinthenearfuture.TheWEC’sOutlookReportin2013indicatedthat development of the renewables not only faces demand challenges, but also significantly depends upon financial and legal supportsfromgovernmentsindevelopingcountries[7].Infact,therenewableenergydevelopmentratehasbeenslowerthanit waspredicted20yearsago[7].Acomparisonofglobalprimaryenergyconsumptionoverthepast10yearsissummarizedin Fig.1.Thefindingsclearlyshowthatthemajorityofconsumptionwasintheformoffossilfuels,whileaslightdecline(0.61%) observedfrom2005to2015.Renewablesonlysharedasmallfractionthatfluctuatedfrom12%to14%,butitseemstohave goneupsteadily. 1.12.1.2 Fossil Fuel Fossilfuel is aprimary energy resource that playsa criticalrole inourdaily activities, includingtransportation, manufacturing, electricityproduction,coolingandheatingsystems,andmanyotheruses[14].Fossilfuelsareformedbynaturalprocesses,suchas anaerobic decomposition of dead organisms, and the energy contained originates in ancient photosynthesis [15]. These fuels FossilFuels 523 2005 Nuclear, 5.7% Solar, 1.0% Wind, 0.2% Other Hydro, 6.0% renewables, 0.5% Oil, 35.6% Gas, 22.7% Coal, 28.3% 2010 Nuclear, 5.1 % Solar, 0.1% Wind, 0.6% Other renewables, Hydro, 6.4% 0.7% Oil, 33.5% Gas, 23.7% Coal, 29.8% 2015 Nuclear, 4.4% Solar, 0.5% Wind, 1.4% Other renewables, Hydro, 6.8% 0.9% Oil, 32.9% Gas, 23.9% Coal, 29.2% Fig.1 Globalprimaryenergyconsumptioncomparisons.DatafromWorldEnergyCouncil.2016Surveyofworldenergyresources,London;2016. Table1 Projectionoftheworld’sregionalenergyconsumption2012–40(EJ) Regions 2012 2025 2040 OECDa 251 274 298 America 124 135 146 Europe 85 92 101 Asia 41 47 51 Non-OECD 322 413 533 Europe 54 58 61 Asia 186 260 340 MiddleEast 34 47 65 Africa 34 32 46 Americas 33 39 50 WorldTotal 591 710 860 aOrganizationforEconomicCooperationandDevelopmentmembercountries.Europe:Austria,Belgium, CzechRepublic,Denmark,Estonia,Finland,France,Germany,Greece,Hungary,Iceland,Ireland,Italy, Luxembourg,theNetherlands,Norway,Poland,Portugal,Slovakia,Slovenia,Spain,Sweden,Switzerland, Turkey,UnitedKingdom.Othermembercountries:Australia,Canada,Chile,Israel,Japan,Mexico,New Zealand,SouthKorea,UnitedStates. Source:ModifiedafterWorldEnergyCouncil.2016Surveyofworldenergyresources,London;2016. 524 Fossil Fuels Table2 Oil,naturalgas,andcoalreservesintopfivecountriesandtheirproductionsin2016 Oil Gas Coal Countries Reserves Production Countries Reserves Production Countries Reserves Production (Mt) (Mt) (tcm) (bcm) (Mt) (Mt) Venezuela 47,000 124.1 Iran 33.5 202.4 UnitedStates 281,582 521.1 Saudi 36,600 285.7 Russian 32.3 579.4 China 244,010 2408.1 Arabia Federation Canada 27,600 218.2 Qatar 24.3 181.2 Russian 160,364 275.4 Federation Iran 21,800 216.4 Turkmenistan 17.5 66.8 Australia 144,818 427.6 Iraq 20,600 218.4 UnitedStates 8.7 749.2 India 94,769 401.3 Global 240,700 4382.4 Global 186.6 3551.6 Global 1,139,331 5223.4 Source:DatafromBP.Availablefrom:http://bp.com/statisticalreview[accessed21.10.17]. formed from the fossilized remains of dead plants [16] are formed by exposure to heat and pressure in the Earth's crust over millionsofyears[17],andtheageoftheorganismsandhencetheresultingfuelsismanytimesolderthan650millionyears[18]. Fossilfuelscontainhighpercentagesofcarbonandincludecoal,oil,andnaturalgas.Someotherusedderivativescanbelistedas kerosene and propane. Fossil fuels cover a range from nonvolatile materials with almost pure carbon (e.g., anthracite coal), to volatilematerialswithlowcarbontohydrogenratios(e.g.,methane)toliquids(e.g.,petroleum).Inhydrocarbonfields,methane canbefoundeitheralone,associatedwithoil,orinotherformsofmethane. Fossil fuels are formed via natural processes continually; however, they are generally considered as nonrenewable resources becausetheytakemillionsofyearstoform,andtheknownreservesarebeingdepletedmuchfasterthanthenewonesbeingmade available[19,20].AsFig.1shows,theglobalprimaryenergyconsumptionin2015consistedofpetroleum32.9%,coal29.2%,and natural gas 23.9%, amounting to an 86.0% share for nonrenewable fossil fuels in primary energy consumption in the world. Nonfossilenergyconsumptionin2015includedhydroelectric6.8%,nuclear4.4%,wind1.4%,solar0.45%,andotherrenewables amountingto0.89%[21].Andworldenergyconsumptionisgrowing. As it is seen clearly, fossil fuels are closely linked to our lives; therefore, it is important to figure out their impacts on the surrounding environment and other related resources [22]. The burning of fossil fuels produces around 21.3 billion tonnes of carbondioxide(CO )peryear.Andnaturalprocessescanonlyabsorbpartofthisrelease,anditisestimatedthatonlyabouthalf 2 ofthisamountcanbeabsorbedbynaturalprocesses.Hence,thereisasurplusof10.65billiontonnesofCO ,whichisreleasedto 2 theatmosphereeveryyear[23].ItisnowacommonknowledgethatCO isagreenhousegas,whichincreasestheatmospheric 2 radiativeforcingduetoitsglobalwarmingpotentialandthereforecontributestoglobalwarming.Thereisaglobaltrendtoward thegenerationofmorerenewableenergytohelpreduceglobalgreenhousegasemissionsincludingtheemissionsfromfossilfuels. Also, the linkage between energy and water has become clearer recently [2,3,24]. The extraction and processing of fossil fuels requirealargeamountofwaterinput,whichfrequentlyimpactsthewaterqualitynegatively[24]. Duetotheenvironmentalconcernsandothers,thecontributionoffossilfuelsisexpectedtodropwiththerapidgrowthof clean and renewable energy sources. Fossil fuel reservoirs are not equally distributed around the world. In 2017, the British Petroleum(BP)publishedreservesandproductionofoil,naturalgasandcoalfromthetopfivecountriesintheyear2016.Table2 showsthatreservesaremainlyconcentratedintheMiddleEast,NorthAmerica,RussianFederation,andAsia.About77%oftotal coal production was exploited from the top five reserves, while only 50% and 24% of global natural gas and oil productions, respectively.Furthermore,theIEA[22]predictedandpublishedtheworldpetroleumandotherliquidfuels,naturalgas,andcoal productionbyOrganisationforEconomicCooperationandDevelopment(OECD)andnon-OECDcountriesovertheperiodfrom 2012to2040(Fig.2)[11]. 1.12.1.3 HubbertPeak Theory AmericangeophysicistM.KingHubbert,in1956,proposedthatfossilfuelproductioninagivenregionovertimewouldfollow roughlyabell-shapedcurve,withoutprovidingapreciseformula.However,forestimatingfutureproductionusingpastobserved discoveries, he later used the Hubbert curve (Fig. 3) – the derivative of the logistic curve (common S-shaped sigmoid curve) [25,26]–whichisanapproximationoftheproductionrateofaresourceovertime.Heassumedthatafterfossilfuel(oil,coal,and naturalgas)reservesarediscoveredandasmoreextractiontakesplace,productionfollowsapproximatelyanexponentialincrease. Andatsomepointofextraction,eventuallyapeakoutputisreached,andproduction startstodeclineuntilitforms,thistime, approximately an exponential decline. The Hubbert curve is roughly symmetrical and has a single peak, satisfying the above- mentionedcharacteristics;andproductionreachesthepeakwhenabouthalfofthefossilfuelthatwillultimatelybeproducedhas beenproduced.Providedanypastfossilfueldiscoveryandproductiondata,aHubbertcurvethatapproximatespastdiscoverydata canbeconstructedandusedtoprovideestimatesforfutureproduction.Eventually,theapproximatetimeofpeakfuelproduction andthetotalamountoffuelthatwouldultimatelybeproducedareestimatedthatway. FossilFuels 525 25 OECD Non-OECD 20 y a 3m/d 15 11.89 on 10 7.12 8.66 Milli 5 7.23 7.23 7.33 0 (A) 2012 2020 2040 7.0 OECD Non-OECD 6.0 5.0 3 m 4.0 n 3.85 o 2.76 Trilli 3.0 2.13 2.0 1.0 1.26 1.47 1.88 0.0 (B) 2012 2025 2040 10,000 OECD Non-OECD 8000 s n n to 6000 6115 6671 7099 o Milli 4000 2000 2029 2174 7133 0 (C) 2012 2025 2040 Fig.2 Worldproductionof(A)petroleumandotherliquidfuels,(B)naturalgas,and(C)coalbyregionsovertheperiodfrom2012to2040. OECD,OrganisationforEconomicCooperationandDevelopment.DatafromUnitedStatesEnergyInformationAdministration.Internationalenergy outlook2016,U.S.DepartmentofEnergy,Washington,DC;2016. 0.25 0.20 0.15 0.10 0.05 0 −6 −4 −2 0 2 4 6 Fig.3 ThestandardHubbertcurve.Forapplications,thexandyscalesarereplacedbytimeandproductionscales. 526 Fossil Fuels 1.12.2 Oil As mentioned earlier, just like natural gas, oil is formed by the anaerobic decomposition of organic matter including phyto- plankton and zooplankton, which were settled in large quantities in deposition basins, such as a seabed or lakebed, over geological time. This organic matter, after being mixed with mud, remained buried under increasing layers of sediment over millionsofyears.Asaresult,theorganicmatterandmudmixturewasexposedtohighpressuresandtemperaturesovermillionsof yearscausingtheorganicmattertochemicallychange,firstintokerogen(awaxymaterial,whichisfoundinoilshales),andthen, withmoreexposuretofurtherheat,intoliquidandgaseoushydrocarbonsinaprocessknownascatagenesis.Throughoutallthese processes,theenergydensityofhydrocarbonsmightincrease;however,theoriginoftheenergyisstilltheancientphotosynthesis. Currently,theworld’sprimaryfuelsourcefortransportationisoil,whichalsoexistsinshaleandtarsands;however,mostoilis pumpedoutofundergroundreservoirs.Oilisextracted,andthenitisprocessedinrefineriestocreatefueloil,gasoline,liquefied petroleumgas,andotherproductslikefertilizers,pesticides,pharmaceuticals,andplastics.However,oilcausesseriousenviron- mental problems and the heavy reliance on oil particularly for transportation makes it difficult to reduce its consumption. Furthermore,theenvironmentaldegradationcausedbyextractionandoilspills,combustionofoilemitsfineparticulates,which canleadtoserioushealthproblemsforhumans,andisalsoamajorsourceofgreenhousegasemissions.Aswekeepdepleting conventional oil sources from underground reservoirs, unconventional sources, such as tar sands and oil shale, attract more attention.Heaviercrudeoilsextractedfromsuchsourcesresultinmoreemissionsandenvironmentaldisturbancecomparedto conventionaloilbecausetheirextractionisinvolvedintheuseofenergyintensivemethods. 1.12.2.1 Sources ofOil Oil comes from both conventional and unconventional sources. The terms, conventional and unconventional sources, are however not clearly defined in the literature and the definitions vary considerably. For instance, Hubbert limited his peak oil prediction in 1956 to the crude oil producible by methods then in use. His later analyses included future improvements in explorationandproduction[27];however,allhispeakoilanalysesexcludedtheoilfromoilsandsandoilshale.Wecangivea 2013study,asanexample,whichpredictedanearlypeak,excludedtheoil,suchasdeepwateroil,tightoil,andoilclosetothe poles, all of which were defined as nonconventional sources [28]. This chapter provides commonly used definitions for con- ventionalandunconventionaloilaspresentedbelow. 1.12.2.1.1 Conventional sources Oilextractedonlandandoffshoreusingstandardtechniquesisdefinedasconventional.Andwithrespecttograde,thoughthe exactdefinitionsofthegradesvarybasedonwheretheoilcomesfrom,thesesourcesarecategorizedaslight,medium,heavy,or extraheavy.Lightoilflowsnaturallytothesurfaceandcansimplybeextractedbypumpingittothesurface.Heavyoilobviously referstotheoilthatdoesnotfloweasilybecauseofitshigherdensity.Whileconventionaltechniquesarepartlyusedforproducing thisheavyoil,typicallytheuseofunconventionalmethodsprovestoprovidebetterrecoveryrates[29]. 1.12.2.1.2 Unconventional sources Itdoesnotmeanthatitwillbesoforever;however,currentlythefollowingoilsourcesareconsideredunconventional. (cid:129) Oil sands: these are unconsolidated sandstone deposits containing large amounts of viscous crude bitumen or extra heavy crudeoil.Theycanberecoveredbysurfaceminingoroilwellsusingsteaminjectionorothertechniques.Suchdeposits are liquefiedbyblendingwithdiluents,upgrading,orheating;andthen,processedatanordinaryoilrefinery.Therecoveryofthese depositsrequiresanadvancedtechnology,whichisdifferentfromaconventionaltechnologyandmoreefficientthanthatofoil shale, for instance, due to the sandstone deposits’ producing oil much more easily compared to oil shale or marl. These formationsarequiteoftencalled"tarsands,"suchasCanadiantarsands;however,thematerialexiststhereisactuallynottar, ratheritisanextraheavyandviscousoilknownasbitumen[30]. (cid:129) Oilshale:oilshaleisusedasacommontermforsedimentaryrock,suchasshaleormarl,whichcontainskerogenthatisyettobe transformedintocrudeoilbythehighpressuresandtemperaturesduetodeepburial.Theseformationsareclosetothesurface; therefore,theyaregenerallymined,crushed,andretorted,eventuallymanufacturingoil(synthetic)fromthekerogen[31]. (cid:129) Tightoil:thisistheoilextractedviahydraulicfracturingfromlow-permeabilityrockdeposits,shaledeposits,andmanytimes fromotherrocktypesaswell[32].Itshouldnotbeconfusedwithshaleoil,whichis,asmentionedabove,theoilmanufactured fromthekerogencontainedinanoilshale. (cid:129) Coalliquefactionorgas-to-liquids(GTLs)product:thesearesynthesizedliquidhydrocarbonsfromtheconversionofcoalor naturalgasbyanumberofprocesses,suchasFischer–Tropschprocess,Bergiusprocess,orKarrickprocess.Sasolcurrentlyhas workingcommercialscalesyntheticoiltechnologiesbasedoncoal-to-liquid(CTL)andnaturalGTLtechnologies,producing $4.40billioninrevenues.Shellhasalsoemployedtheseprocessestoconvertandrecyclewasteflaregasburntoffatoilwells andrefineriesintousablesyntheticoil.However,forCTLconversion,ithasbeennotedthatcoalreservesmaynotbesufficient tosupplyworld’sneedsforbothliquidfuelsandelectricpowergeneration[33]. (cid:129) Minor sources: these include thermal depolymerization, which could indefinitely be used to produce oil out of waste feed- stocks,suchasagriculturalwaste,garbage,andsewage.Forinstance,LosAlamosLaboratory,UnitedStates,statedthathydrogen FossilFuels 527 –potentiallyproducedusinghotfluidfromnuclearreactorstosplitwaterintohydrogenandoxygen–incombinationwith sequesteredCO couldbeusedtoproducemethanol,whichcouldthenbeconvertedintogasoline[34]. 2 1.12.2.2 Oil Reserves Primary energy source levels are the carbon based fossil energy reserves in the ground. Flows or daily productions of such sourcesareknownasproductionoffossilfuelsfromthesereserves.Whenwetalkaboutoilreserves,wespecificallymeanthe amountofcrudeoil,whichcantechnicallyberecoveredinafinanciallyfeasiblemanneratthepresentpriceofoil[35].Thetotal estimatedamountofoilinanoilreservoir,includingbothproducibleandnonproducibleoil,iscalledoil-in-place.Duetothe limitationsofoilextractiontechnologiesatthetimeandreservoircharacteristics,notthewholebutonlyaportionofthisoilcan be recovered and brought to the surface of the Earth. And this producible portion is considered as reserves. Oil resources howeverincludealloilthatcantechnicallyberecoveredatanyprice,notonlyatthepresentprice.Therefore,asitisclearlyseen and understood, unlike oil resources, oil reserves vary as a function of the price. Reserves for instance typically indicate the reservesforapointofinterest,suchasasingleoilwell,asingleoilreservoir,asingleoilfield,asinglecountry,orthewhole world.Theratioofreservestothetotalamountofoilinaspecificreservoiriscalledtherecoveryfactor.Thence,themethodof oilrecoveryused,theoperationitself,andtherelevanttechnologicaldevelopmentsalltogetherdeterminetherecoveryfactorfor agivenfield,forinstance[36].Mostearlyestimatesoftheoilfieldreservesaregenerallyconsideredconservativeandtendto growwithtime(whichiscalledreservesgrowth)asafunctionofnewtechnologicaldevelopments[37].Fig.4showstheglobal oilreservesinbillionbarrels(bbl)in2013. Oil producing nations do not typically reveal their engineered reservoir data due to their national security concerns, and instead,providemanipulateddataforpoliticalreasons[38,39].However,BPattheendof2016reported(seeTable3)thatthe highestprovedoilreserves(includingnonconventionaloildeposits)arelocatedinVenezuela(17.6%ofglobalreserves),Saudi Arabia(15.6%ofglobalreserves),Canada(10%ofglobalreserves),Iran(9.3%),andIraq(9.0%),withthehighestreserves-to- production (R/P) ratios belonging to Venezuela and Canada, 341.1 and 105.1 years, respectively, and the global ratio of 50.6 years.OrganizationofthePetroleumExportingCountries(OPEC)dataattheendof2016showedsimilarreservenumbers[40]. 301 bn bbl 267 bn bbl 110 bn bbl 30 bn bbl 0 Fig.4 Globalmapofoilreservesin2013.ReproducedfromWikipedia.Availablefrom:https://en.wikipedia.org/wiki/Oil_reserves[accessed21.10.17]. Table3 Provedoilreservesintopfivecountriesbetween1996and2016(reservelevelsareinthousandmillionbarrels) Countries 1996 2006 2016 Shareoftotal(%) Reserves-to-production(R/P)ratio Venezuela 72.7 87.3 300.9 17.6 341.1 SaudiArabia 261.4 264.3 266.5 15.6 59.0 Canada 48.9 179.4 171.5 10.0 105.1 Iran 92.6 138.4 158.4 9.3 94.1 Iraq 112.0 115.0 153.0 9.0 93.6 Totalworld 1148.8 1388.3 1706.7 100.0 50.6 Source:DatafromBP.Availablefrom:http://bp.com/statisticalreview[accessed21.10.17]. 528 Fossil Fuels 1.12.2.2.1 Reserves of unconventional oil Oil becomes less and less available every passing year. And this can only be substituted with production of liquid fuels from unconventionalfuelsources,suchasoilsands,tightoil,shaleoil,ultra-heavyoils,biofueltechnologies,CTL,andGTLtechnol- ogies [41]. That is why, International Energy Outlook (IEO) in its 2007 and later reports, in presenting world energy reserves, productionandconsumption,usedtheword“Liquids”ratherthanthe“Oil”[42,43].Also,biofuelswasincludedinthe“Liquids” sectioninsteadofinthe“Renewables”in2009[44].However,theinclusionofnaturalgasliquidsinthe“Liquids”sectionhasup tocertainextentbeencriticizedasitisachemicalfeedstock(by-productofnaturalgas)andgenerallynotusedasatransportfuel [45]. Asmentionedearlier,oilreserveestimatesarefunctionoftheoilprice;andtherefore,asunconventionalsourcesareincludedin thepictureandnewtechniquesreducethecostofextraction,thereserveestimateswillvaryintime.Itisawellknownfactthatitis more labor and resource intensive to produce the unconventional sources, which obviously require additional energy to refine (i.e.,higherproductioncosts).Also,ona“well-to-tank”basis,approx.threetimesmoregreenhousegasemissionsareemittedper bblequivalent[46,47].Theenergyandotherresources needed,andenvironmental effectsofextractingunconventional sources havealwaysbeenhighprohibitingtheextractionofsuchsources;however,anumberofmajorunconventionalsourceshavebeen broughttothetableforlarge-scaleproduction.TheoilsandsintheWesternCanadianSedimentaryBasin(seeFig.5)[48],theoil shaleoftheGreenRiverFormationinColorado,Utah,andWyomingintheUnitedStates,andtheextraheavyoilintheOrinoco BeltofVenezuela[49],canbegivenasexamplesofsuchefforts.Bitumenhasalsobeenextractedformanydecadesbycompanies, such as Suncor and Syncrude; but with the support of new extraction technologies, production has tremendously increased in recentyears[50].Itisestimatedthat,takentogether,theseresourceoccurrencesintheWesternHemisphere,areapprox.equalto the identified reserves of conventional crude oil sources in the Middle East [51]. It is believed that the world's reserves of unconventionaloilareseveraltimeslargerthanthoseofconventionaloil[52](seeFig.6).TheUSGeologicalSurvey,inOctober 2009,updatedVenezuela’sOrinocotarsandsrecoverablemeanvalueto513billionbbls(81.6billionm3),witha90%chanceof beingwithintherangeof380–652billionbbls(103.7billionm3),makingthisareaasoneoftheworld'slargestrecoverableoil fields[53]. Oilextractedfromunconventionalsourcescontainssulfurandheavymetals,whichareenergyintensivetoextractandcanleave thesiteinsomecases[46,54].ThesamethingistrueformuchoftheundevelopedconventionaloilreservesintheMiddleEast, whichisheavy,viscous,andcontaminatedwithsulfurandmetals[55].However,thesesourcesbecomemoreappealingfinancially Fig.5 Syncrude'sMildredLakeminesiteandplantnearFortMcMurray,Alberta,Canada.Theyellowstructuresarethebasesofpyramidsmade ofsulfur–noteconomicaltosellsoSyncrudestockpilesitinstead.Behindthepilesisthetailingspond,recognizedasthelargestdaminthe world.Theextractionplantistotherightofthispictureandthemineistotheleft.ReproducedfromWikipedia.Availablefrom:https://en. wikipedia.org/wiki/Peak_oil#cite_note-102[accessed21.10.17]. FossilFuels 529 Total world oil reserves 80% Conventional oil 70% Heavy oil 60% Extra heavy oil Oil sands bitumen 50% 40% 30% 20% 10% 0% Conventional Unconventional Fig.6 Comparisonofconventionalandunconventionaloilreserves.ReproducedfromAlboudwarejH,FelixJ,TaylorS,etal.Highlightingheavy oil.OilfieldRev2006;18(2):34–53. 150 North America 160 S & C America Europe and Eurasia Middle East Africa 140 Asia Pacific 120 World 120 180 90 80 60 60 40 30 20 North S & C Europe Middle Africa Asia 0 86 91 96 01 06 11 16 0 America America and East Pacific Eurasia Fig.7 2016(left)andhistory(right)ofregionaloilreserves-to-production(R/P)ratios(years).ReproducedfromBP.Availablefrom:http://bp. com/statisticalreview[accessed21.10.17]. whenoilpricesgohigh[56].Mackenzie[57]forecastedthattheworld'sextraoilsupplybytheearly2020swilllikelybecoming fromunconventionaloilsources. Theoilreservesweresuspectedtoberunningoutinthecomingdecades.However,withthehelpofadvancedtechnologies, moreoilreserveshavebeendiscoveredandbecameviable;asaresult,theglobaloilreservesincreasedby60%withinpast20years witha25%growthinoilproduction[7],nowhavingSouthandCentralAmericathehighest(120years)oilR/Pratiosratherthan theMiddleEast(seeFig.7).Itispresentlyexpectedtoexpandfurtherasunconventionaloilsourcesmentionedabovearetaken intoaccount.Weknowthatoilsandsaremixturecompoundsthatcontainclay,water,sand,andbitumen[58];andGosselinetal. [195,59]indicatedthattheAlbertaoilsands(seeFig.5),forinstance,havegreatcompetitivenessinCanadathataccountedfor approximately50%oftotalCanadianoilproductionin2009.Also,thereisnooilintheoilshale;however,itcontainsaunique materialcalledkerogen,whichisaprecursorofcrudeoil[58].Theworldresourcesofoilshaleareestimatedaround730trillion liters, which is reported to have four times greater than crude oil reserves currently [21]. Both oil sands and oil shale must be refinedbeforetheycanworkasconventionalcrudeoil[60].Therefore,theynotonlyrepresentanincreasedoilreserve,butalsoan 530 Fossil Fuels increasedenvironmentalburden.Themoretechnologiesemployedforextractionandprocessing,themoresevereistheimpacton air,water,landandenergyresources. 1.12.2.3 Oil Production,Demand andTrade Fig. 8 below shows the global distribution of oil producing nations in 2013 [61]. BP Energy Outlook 2017 [62] provided a detailedreportforthecurrentandpast20year’soilproductiondataaswellastheprojectionsforthenext20years.Basedonthis report,annualproductioninmilliontonnesofoilequivalent(Mtoe),oil,coal,andnaturalgasprovided85.4%ofprimaryenergy productionin2015(32.4%þ29.2%þ23.9%,respectively).Currently,oilistheworld'slargestprimarysourceofenergy. Table4indicatesthatglobaloilproductionin2015increasedby32.7%comparedtothatin1995,andisprojectedtoincrease furtherinthenext20years(9.3%basedonthe2015productionfigures).ThemainincreasehasbeenandwillbeintheMiddle EastandNorthAmerica(Canada,Mexico,andtheUnitedStates),whilethereisamajordeclineinoilproductioninEuropeand almostasteadyproductioninAfricaandAsiaPacific. Table5,ontheotherhand,showstheregionaloilproductionsin1995,2015,andprojectedoilproductionsin2035,aswellas therelevantchangesinregionalproductions.Basedonthisreport,theMiddleEast,NorthAmerica,andtheCommonwealthof IndependentStates(CIS)willcontinuetopreservetheirleadingsharesofglobaloilproductionwithfurtherproductionincreases through2035,whiletheSouthandCentralAmericasustainingitssharewithincreasedproduction,andotherregionsobservinga Barrels per day (bbl/day) ≥ 10,000,000 ≥ 3,000,000 ≥ 1,000,000 ≥ 500,000 ≥ 150,000 ≥ 100,000 ≥ 50,000 ≥ 25,000 ≥ 10,000 ≥ 5000 ≥ 1000 > 0 0 Countries by oil production in 2013 Fig.8 Globalmapofoilproducingcountriesin2013.ThemapisAliZifan’swork,whichwaspreparedusingdatafromCIAWorldFactbook. ReproducedfromWikipedia.Availablefrom:https://en.wikipedia.org/wiki/Peak_oil#cite_note-102[accessed21.10.17]. Table4 Oilproductionbyregion(milliontonnesofoilequivalent) Regions Years 1995 2000 2005 2010 2015 2020 2025 2030 2035 NorthAmerica 645.8 642.6 637.8 638.8 910.3 940.0 1007.5 995.9 1004.1 S&CAmerica 300.1 343.4 374.4 375.8 396.0 389.9 404.5 434.8 454.0 Europe 311.1 332.3 268.6 196.5 164.7 146.4 133.3 94.6 66.6 CommonwealthofIndependentStates(CIS) 358.3 396.2 580.3 662.8 682.0 692.7 708.3 716.2 730.2 MiddleEast 979.2 1151.1 1227.4 1220.7 1412.4 1508.0 1618.2 1727.6 1818.7 Africa 339.6 370.9 466.4 481.8 398.0 386.6 392.8 390.2 382.7 AsiaPacific 352.2 380.8 382.4 402.4 398.3 355.8 348.7 331.6 311.9 Total 3286.3 3617.4 3937.5 3978.8 4361.6 4419.5 4613.2 4690.9 4768.1 Source:DatafromBP.Availablefrom:http://bp.com/statisticalreview[accessed21.10.17].