The Donets Basin (Ukraine/Russia) contains one of the major coal fields in the ... during 2001 was 83.4 mio. t. in the Ukrainian and 6.5 mio. t. in the Russian part ...
CoalGeology of theDonetsBasin(Ukraine/Russia): An Overview V. A. Privalov,R. F.Sachsenhofer. E. A. Panovaand V. A. Antsiferov The DonetsBasin(Ukraine/Russia) containsoneof the majorcoalfieldsin theworldwithprovenreservesin theorderof 60 Gt.The Carboniferous basinfill hostsabout130seams,eachwitha thickness over0.45m. Coalrankrangesfrom subbituminous to anthracite. The thickness of coalseamscurrentlyminedis in the rangeof 0.6to 2.5m. Production during2001was83.4mio.t. in the Ukrainian and6.5mio.t. in the Russianpartof the basin.Coalseamsusuallyhave highashyields(12-'18"/")andhighsulphurcontents(2.5-3.5%), butthesedatavarysignificantly depending on peat facies.Coalminesin the DonetsBasinare amongthe gasiestin the world.The averagemethanecontentof coalis 14.7m3lt,butnumerous seamshavesignificantly a severemine highergascontent. Thehighmethane contentpresents safetyproblem.On the otherhand,it represents alsoa highpotentialfor coalbed methaneprojects.Coaland gasoulburstsconstituteanothermajormininghazardand accountfor manyfatalities. Kohlengeologiedes Donets-Beckens(lJkraine/Russtand): Eine Übersichf. Das Donets-Becken(Ukraine/Russland) beinhaltet eine der gröBtenKohlenlagerstätten Vorrätenvon ca. 60 Gt. Die karbone der Erdemit nachgewiesenen Beckenfüllung beinhaltet ca. 130Flözemit einerMächtigkeit reichtvom Glanzbraunüber45 cm. Der Inkohlungsgrad kohlen-biszumAnthrazitstadium. DieMächtigkeit zwischen 0,6 und2,5m. lm der heuteabgebauten Flözeschwankt ukrainischen Teildes Beckenswurde200183,4Mio.t Kohlegefördert, im russischen Teil6,5Mio.t. Die Flözesind meistasche-(12-18%) und schwefelreich (2,5-3,5%). Abhängigvom Ablagerungsmilieu schwanken die Gehalte jedochbeträchtlich. Die Kohlenbergwerke im DonetsBeckengehörenzu denweltweitgasreichsten. DerdurchschnittlicheMethangehalt der Kohlebeträgl14,7m3lt, der Gasgehalt zahlreicher Flözeistjedochdeutlichhöher.Die hohen Methangehalte stelleneingroßesSicherheitsproblem FlözgaszeigensieaucheinhohesPotenzialfür dar.Gleichzeitig projekte. HäufigeKohle-undGasausbrüche fürvieleUnglücke. stelleneineweitereGefahrdarundsindmitdieUrsache
The DonetsBasin(Donbas) is locatedmainlyin the Ukrainewiththe easternpartof the basinextendinginto Russia(Fig.1).The basincoversan areaof 60000km, andcontains oneof themajorcoalfieldsintheworldwith provenreservesin theorderof 60 Gt (Zhykalyak and Privalov,2002;Nazarovaet al.,2003). TheCarboniferous basinfillhostsabout130seams, each with a thicknessover 0.45m. Coal rank ranges from subbituminous (Glanzbraunkohle) to anthracite (Levenshtein et al.,1991a).Thethickness of coalseams currentlyminedis in the rangeof 0.6 to 2.5m. In 1991, beforethecollapseof the SovietUnion,therewereabout ''undergroundmines (Marshall 300 operating et al., 1ee6). The averagemethanecontentof coal is 14.7mslt coal (Marshall etal., 1996),but numerous seamshave presenting significantly highergascontent, a highpotential for coal minemethaneprojects(e.9.Triplettet al., 2001).On the other hand,the high methanecontent presentsa severemine safetyproblem.Actually,coal Doz"Dr. VitaliyA. PrivalovDonetskNationalTechnicalUniversity,Artemstr.58, 83000Donetsk/Ukraine; Univ.Prof.Dr. Reinhard F. Sachsenhofer, Institutfür Geowissenschaften der Montanuniversität Leoben,8700 Leoben/Austria; Dr. ElenaA. Panova,UkrNlMl,NationalAcademyof Scienceof Ukraine, Tchelyuskintsev str.291, 83121Donetsk/Ukraine; VadimA. Antslferou UkrNlMl,NationalAcademyof Scienceof Ukraine, Tchelyuskintsev str.291, 83121Donetsk/Ukraine. 21 2 p rivatov,Sachsenhofe r, Panova, Antsiferov
minesin the DonetsBasinare amongthe most dangerousin theworld. amounts Although the DonetsBasinhostssignificant of coal and gas, its geologyand miningindustryare poorlyknownin middleandwesternEuropean countries. is to fillthisgap. Mainaimof the presentcontribution
andBasinStructure 1. BasinEvolution The DonetsBasinformspartof the Pripyat-Dniepr-Doriftstrucnets-Karpinsky Basin(Fig.1),a LateDevonian ture locatedon the southernpart of the EasternEuropean craton (Stovbaand Stephenson,1999; Stephensonetal., 2001).Someimportantaspectsof the in Fig.2. evolution of the basinaresummarized preTotalthicknessof Devonian and syn-riftrocksis of the DonetsBasin,butupto 6 km 750m at themargins et al., 2003).Major alongthe basinaxis (Maystrenko post-rift occurred duringthe Permo-Carbonsubsidence up to 14km thick, iferous. TheCarboniferous sequence, into lithostratigraphic unitsnamedsuites is subdivided andStepanov, A (C,'),B (C,'),C (C,'),to P (C.3)(Lutugin 1913).Thecoal-bearing succession consistsof elemencoal, tary sequences, composedof fluvialsandstone, marinelimestone or claystone, anddeltaicclaystoneand (Shirokov, 1963;Shulga, 1981).Thesequences siltstone are controlledby sea levelvariationsdue to glaciations (lzartet al.,2003).The on theGondwana supercontinent percentageof continentaldeposits is higher in the BHM,149.Jg. (2004),Heft6
Fig. 1. Geologicsketch map of the Donets Basin (modifiedafter Popov,1963): Geologicalcross-sectionafter Maystrenkoet al. (2003)
andsainiotet al. (2003)
westernpart than in the easternpad of the Donets Basin.Withthe exception of the carbonate suiteA (C,t) of Turnaisian to earlyViseanage,coalseamsand intercalationsof coal are presenlthroughout the Carboniferoussuccession. However, (suite lowerSerpukhovian C) and Moscovian successions (suitesK to M) are especiallyrichin coal(Levenshtein et al.,1991b). Permianrocksare preserved alongthe westernand northern basinmargins, wheretheyarerepresented bya sandstone-mudstone serieswith limestoneinterbeds (Nesterenko, 1978).Thickevaporites hostingeconomic salt and gypsumdepositsoccurin Asselianand Sakmarianlevels.Only relatively thin sediments were depositedduringthe Mesozoic andCenozoic. lmportantinformation on the deep structureof the DonbasFoldbelt, paftof theDnieprwhichistheinverted DonetsBasin,is provided bv the"DOBRE" reflection line BHM,149.Jg. (2004),Heft6
(Maystrenko etal.,2003;Fig.1).The structure of the centralbasinis dominated by WNW-ESE trendingfolds (Fig.1).Thesefoldsare fairlytightand in someplaces overturned. The Main(Gorlovka) is the largest Anticline andmostpervasive foldin thiszone.lt is an almostsymmetricstructurewith steeplydippinglimbs(60"-80"), complicated by faultsas (oblique)thrusts,as oblique normaland strike-slip faultsdeveloped at its hinge,in (Saintot whichdextralmovementhas beenrecognised et al., 2003).The Main Anticlineis borderedby two gentlesynclines(Northand SouthSyncline)and anticlines(Fig.1). Majorthrustsoccuralongthe nodhern marginof the basin.Minorfolds,reversed faultsand rotatedfaultblocksprevailalongthesouthern boundary of the basin.The age of the compressional structures is a matterof controversy. FollowingtraditionalideasPopov (1963),Nagornyand Nagorny(1976),Privalovetal. Privalov,Sachsenhofer, Panova,Antsiferov21 3
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tuminous(Glanzbraunkohle: 0.4-0.6% Rr) and bituminous coals (Steinkohle: 0.6-2.5% Rr) are restrictedto the westernand northernbasin margins.Coalification patternsin the DonetsBasinwere mappedby Levenshteinetal. (1991b;Fig.5A).lso-reflectance linesgenerallyfollowthe mainstructural elements, likeantiforms and synforms.Breaks in coalificationare observed acrossthrust planes.Coalification, therefore,is older thanthe mainthrusting event.On the otherhand,transectsacrossthe Main(Gorlovka) Anticlineshowthat the dip of iso-reflectivity lines is gentlewhereasthe dip of beddingplanesis steep(insetin Fig.5A). This is clear evidencethat coalification alongthe GorlovkaAnticline predatesthe late stagesof its formation,but postdates its earlystages. BHM,149.Jg. (2004),Heft6
Fig.5. (A) Coalificationmap of the Donets Basin at the top of the Carboniferoussequence (modifiedafter Levenshteinetal,, 1991a). (B) Some aspects of the thermal historyof the basin are indicatedaccordingto Sachsenhoferet al. (2002). lsolinesshow the heat flow distributionduring maximumPermianburial.Areas with a Permo-Triassicheat flow event norlh of Krasnoarmeiskand east ol Donetskare highlightedby grey shading.Numbersin boxes indicatethe amountof post-Carboniferous erosionin km. The positionof intrusive bodies (Aleksandrovet al., 1996) is indicatedtogetherwith the locationof epigeneticmineraldepositsand occurrences(Lazarenkoet al., 1975)
BHM,149.Jg. (200a),Heft6
Panova,Antsiferov21 7 Privalov,Sachsenhofer,
The rankof specificstratigraphic unitsincreases towardsthebasincenter.Forexample, vitrinite reflectance of a coalseamin suiteK (kr)is below0.6% Rr SW of Donetskand N of Lugansk,but above6.0% Rr near KrasnijLuch,despitea similarpresent-day elevation (sea level).Anomalouslyhigh coalification including naturalcoke is observedin close vicinity(several metres)to magmaticsills and stocksSW of Donetsk (e.9.Jernovaya, 1997;Fig.5 A). Sachsenhofer et al. (2002)appliednumericmodels to assessthe different factorswhichcontrolcoalification patternsin the Donets Basin. Among these are (Fis.5B): - depthof Carboniferous rocksduringmaximum(permian)burial, Permianuolift - lateralheatflow variations duringmaximumburial.
-
Theresulting patternwasoverprinted coalificaton by: Permian(-275 Ma) sillsand stocks,whichcoked seamsSW of Donetsk. However, theamountof heat transported by the magmaticrockswas not high enoughto causeregional heatflowandcoalification anomalies. A late Permian/early Triassic(-250 Ma) heating event,whichwas most probablycausedby magmaticintrusions (Spiegel et al.,2004). 4. Gases in Coal (Methane,COr)
Coalminesin theDonetsBasinareamongthegasiestin the world(Marshall et al., 1996).The averagemethane contentof coalis 14.7m% (Marshall etal., 1996),but numerous seamshavesignificantly highergas content. Mineswith seams,which producemore than 40 m3/t
minedcoal are highlightedin Figs.3 and 6. Some seams i n s o m e m i n e se v e n c o n t a i nm o r e t h a n 1 0 0 m 3 4m i n e d coal.The high methanecontentpresentsa severe mine safetyproblemin this area. On the other hand, it represents also a high potentialfor coal bed methane(CBM) projects(e.9.Triplettet al., 2001). ' A c c o r d i n gt o M a r s h a l le t a l . ( 1 9 9 6 ) ,i n 1 9 9 1 n e a r l y 3 . 4 x 1 O ' m 3 o f m e t h a n e w e r e l i b e r a t e dw i t h 1 6 7 o (539x 106m3)capturedby methanedrainagesystems. Only 170x106m3 of this methanewere used, thus 'l 3.2 x O' m3were vented to the atmosphere.Within the last ten years, the relation between these numbers changed insignificantly, but because of a decreasing coal production,the total amounts were reduced by r o u g h l y5 0 % . There is a clear depth dependencyof the gas composition. Within the uppermost few hundred meters methaneis often missingand N, and CO, are prevailing (gas weathering or "COr-nitrogen"zone). Below this zone followsa transitionzone with methanecontentsincreasingdownwardsfrom 0 to 70"Ä (nitrogen-methane zone) and the methanezone with more than 70o/" CHa. The thicknessof the gas weatheringzone rangesfrom 50 m (e.9. Makeevkaregion),to severalhundredmeter (Brizhanyevand Panov,1990;Fig.6) and is probablyrelated to the present day stress field (Panova and Privalov,2001; Privalov,2003). The isotopic and chemical compositionof carbon clearlyindicatesthe thermogenicorigin of the methane ( F i g . 6 ) .M e t h a n eo c c u r sw i t h i nt h e c o a l s e a m ,b u t a l s o within sandstone reservoirs. For examole. the total methane resourcewithin sandstonereservoirsis estim a t e d 1 2 . 9x 1 0 sm s i n t h e Z a s y a d k o m i n e a n d 9 . 1x 1 O 'm 3i n t h e G l u b o k a y am i n e( T r i p p l eet t a l . ,2 0 0 1, see Fig.6 for position of mines). The study of these sandstonereservoirsis important,becausethe coal gas migrated into the sandstonereservoircan come back
Fig 6. Topof the methane zonein different partsof the DonetsBasin(according to datafromBrizhanyev andPanov,1990).Dataon CO,contents according to Brizhanyev andKraschenko (1975). Theposition of poiential CBMsites(Prikhodchenko andPrikhodchenko, 2001)andgas-bearing cupolas is shown.Theinsetshowsisotope dataof coal-bed methane fromtwowells(afterPrivalov etal.,2004)
21 8 privatov,Sachsenhofer, Panova.Antsiferov
BHM,149.Jg. (2004),Heft6
into coal galleriesduringexploitation by fracturesand faults. Somedomalstructures alongthe nonhernmarginal faultof the DonetsBasinand in the southernKrasnoarmeisk and Yuzhno-Donbassky regionshost conventionalgas deposits(Fig.6).Someof theseare or were exploited(Brizhanyev and Galazov,1987; Ulmishek et al.,1994). Thereare largeareaswithhighrankcoalswithinthe Donets Basin where no methane,but significant amountsof CO,occur(Fig.6). In the Dolzhansky-Rovenetskyregionthe CO, contentin someminesis up to 35 m3/tminedcoal.CO, constitutes a significant mine safetyproblemwithinthesemines.Perhapsthe lackof methaneis dueto demethanization duringmajorCretaceous uplift developedmainly along the southerneasternmarginof the basinand the occupation of the freespaceby CO, (Privalov, 2002).
5. CoalMiningin theDonetsBasin Table1 givesan overviewon somemilestones of early coalexploration andextraction in the DonetsBasin. Table 1. Some milestones of early coal exploration and extraction in the Donets Basin 1722 1723 1724 1796 1806 1836 1866 1868 1892-94
PeterI the Greai signs an order for expeditionto Don, Voronezhregionsfor coal exploration Expedition, drillingof 100-130m deep boreholes Extractionof coal near Bakhmut l"tcoal mine (LisitchyaGuly),39 m deep Foundationof Lisitchansk"Steiger"school (4 years of education) Foundationöf Kapitalnayamine in the Lisitchansk regron Dagmaramine in the Lisitchanskregionreachesa depthof 128 m Kotchegarka minein Gorlovkatown (closedin 2000) Expeditionsfor mappingthe Donets Basin in the scale of 1 :42OOO(F. N. Tchernishev. L. l. Lutuoin. N. N. Yakovlev,P. l. Stepanov,A. A. Gapeev).ti. t. Lebedevsuggestedthe term "suite".
ln 1991202 coalmineswereactivein the Ukrainian paft of the DonetsBasin.This numberdecreasedtill 2002to 161. In the mid-1990s, coalproduction dropped from164.8Mt (1990)lo 71.7Mt (1996),beforeinching backto 83.4Mt in 2001.In the Russianoartof the Donets Basinthe numberof minesdecreasedfrom 67 (1990)to 18,whichproduced 5.4Mt of coalduring2002 (Nazarova et al., 2003).93 % of the minedcoal in the Russianpaftis anthracite. Depending on coal rankthe coal eitheris usedfor electricpowergenerationor is processedinto cokefor the ironandsteelindustry. Thedeclinein coalproduction duringthe 1990swas causedmainlyby the collapseof domesticdemandand the closingof heavyindustrysinceUkrainebecameindependent in 1991.Ukrainian coalminingindustryhas employedaround450000people,suffersnow from labourstrikes,hazardeous workingconditions, inefficiency (Table and still low productivity 2), consumernonpayments,unpaidwages,hugedebts,andoutmoded equipment.Main reasonfor the latterwas the investment policyof the formerSovietUnion:Coal miningoperationswereplannedto be reducedin the DonetsBasin, becauseit was possibleto developcoal fieldsin the easternregionsof Russiacontaining cheapercoal. BHM,149.Jg. (2004),Heft6
fable 2. Productivity index 1996-1998
Averageperworker(Vmonth) (Vday) Faceproductivity Formechanized faces(Vday)
1998
1996
1997
15.8 244 357
18.2 19.8 289 312 421 463
They are The geological resources are significant. outsidebalsubdivided into balancesheetresources, ance sheet resourcesand prognosticresources(see Fettweis,1979 for furtherdetails).Differentthreshold as valuesareusedfor different coaltypesto be included balancesheet resources(Table3). Data on balance sheetresoucesare presentedin Table4. Table 3. Threshold values for balance sheet resources
Coking coal Energeticcoal Antracite
Thickness
Ashyield
Sulphur
> 0.55 m > 0.60 m > 0.60 m
< 40 "/o
