FORMATION EVALUATION DENSITY AND NEUTRON LOGS Summer 2010Fluorescent Intervls !n 1U Sn" S#r$ trns!t!on %et&een o!l sturte" $' n" non($' o%serve" %' )luorescence !n core sm$lesGEOLOGICAL AND PETROPHYSICAL DATA USED TO DEFINE FLOW UNITS *ore L!t#o)c!es Flo& Un!ts +etro$#'s!cl Dt +ore T'$es Gmm R' Lo, *ore +lu,s vsk Capillary Pressure 5 4 3 2 1 Mo"!)!e" )rom E%n-s et l./ 1002+OROSITY TOOLS Son!c Dens!t' NeutronOVERVIE1 Intro"uct!on to Nucler lo,,!n, Rev!e& o) %s!c tools Dens!t' Tools Neutron Tools A$$l!ct!ons2L!m!tt!ons Lo, e3m$lesNATURAL RADIOA*TIVITY S$ontneous em!ss!on o) n" $rt!cles n"r"!t!on )rom t#e nucleus o)tom Al$# $rt!cle 4 2 neutrons 5 2 $rotons 6sme s #el!um nucleus7 8et $rt!cle 4 #!,# veloc!t' electrons Gmm r's 4 electrom,net!c r"!t!on 6no mss or c#r,e9 ener,' !n MeV7FAMILY OF NU*LEAR TOOLS Particle Source Application GR Neutrons Natural GR Emitted GR Neutrons Emitted Shaliness Correlation Porosity Porosity Density Lithology Gas Oil GR tools Neutron tool Density toolsDENSITY LOGSDENSITY : +OROSITY MEASUREMENTS Uses Dens!t' +oros!t' L!t#olo,' *urves 8ul- "ens!t' ( b a n d ) Pe *OM+ENSATED DENSITY LOG e D %cFrom ;ll!%urton 6EL < 100=71#' #s Son!c %een "!s$lce" s $#! tool +oros!t' cn %e "eterm!ne" &!t#out $rec!se -no&le",e o) roc- mtr!3 No nee" )or com$ct!on correct!on Overl' o) "ens!t'(neutron e3cellent !n"!ctor o) ,s Trns!t!ons )rom one roc- t'$e to not#er "etecte" S#le e))ects more ev!"entDENSITY +RIN*I+LE Detect GR>s )rom t#e source !c# #ve %een scttere" %c- %' t#e )ormt!on Formation Lo Density !indos "ydraulic sonde Sta#ili$er S%id Cesium Source Caliper armDetectors Gamma rays Near Detector &ungsten 'ore Liner Gamma ray emitting source Far Detector &ungsten Shield+RIN*I+LE Gmm r's em!tte" )rom r"!oct!ve source Gmm r's coll!"e &!t# electrons !n )ormt!on/ los!n, ener,' Detectors mesure !ntens!t' o) %c-scttere" ,mm r's ;!,# ener,' GR relte to ( Dens!t' Lo& ener,' GR relte to ( L!t#olo,'GAMMA(RAY GENERATION *#em!cl source ( Focuse" ( T'$!cl $ro$ert!es *es!um (1?= mter!l 1.= *ur!e stren,t# ?? 'er #l)(l!)e @@2 -eV ,mm(r' ener,'GAMMA RAY INTERA*TIONS 1IT; MATTER +!r +ro"uct!on *om$ton Sctter!n, +#otoelectr!c A"sor$t!on+AIR +RODU*TION Not o) s!,n!)!cnce to "ens!t' tool o$ert!on s!nce t#e source stren,t# !s 0.@@2 MeV n" !t reAu!res 1.02 MeV )or $!r $ro"uct!on 6 0.B1 MeV !s t#e ener,' eAu!vlent o) t#e mss o) one electron 7GAMMA RAY S*ATTERING *om$ton E))ect Me"!um to ;!,# Ener,' GR>s ( scttere" %' electrons !n )ormt!on Nucleus Eo=ho E=h e-( ec# !nterct!on loses ener,' ( more electrons 4C more sctter!n, ( Relte" to elect. : roc- "en. Eo=ho X ray +#otoelectr!c E))ect Lo& Ener,' GR>s ( %sor%e" %' toms ( more electrons 4C more %sor$t!on ( In"!ctes t#e tom!c num%er ( l!t#olo,' e- *OM+TON S*ATTERING Mesur!n, t#e num%er o) ,mm r's !n t#e *om$ton Sctter!n, ener,' rn,e ,!ves us t#e %ul- "ens!t'+;OTOELE*TRI* A8SOR+TION T#e num%er o) ,mm r's c$%le o) $#otoelectr!c %sor$t!on !n"!ctes t#e Atom!c Num%er n" #ence t#e +e T#!s !n)ormt!on !n"!ctes t#e l!t#olo,'1;AT T;E DETE*TOR DSEESE L!t#olo,' Re,!on 6+#otoelectr!c e))ect7 Dens!t' Re,!on 6*om$ton sctter!n,7 SourceEFFE*T OF FORMATION DENSITY ON DETE*TOR *OUNT RATES At. No. sme9 "!))erent "ens!t'EFFE*T OF FORMATION ATOMI* NUM8ER ON DETE*TOR *OUNT RATES Dens!t' sme9 At. No. "!))erentDENSITY LOGS 8ul- "ens!t'/ %/ !s "e$en"ent u$onF L!t#olo,' Formt!on $oros!t' Dens!t' n" sturt!on o) )lu!"s !n $oresDENSITY LOG GR 0 API 200 RHOB 2 G/C3 3 CALIX 6 IN 16 DRHO 0!25G/C3 0!25 CALIY 6 IN 16 4100 Gmm r' Dens!t' Dens!t' correct!on 4200 *l!$er From NE3T/ 10008ULG DENSITY INTER+RETATION ( 1 T#e %ul- "ens!t' 6!n ,2cc7 !s t#e &e!,#te" sum o) t#e mtr!3 n" )lu!" "ens!t!es b = ( ) * m a + f lT'$!cl vlues Mtr!3 "ens!t' 2.@B SS9 2.=1 LS9 2.H= Dol Flu!" "ens!t' 0.0 < 1.0 O8M n" )res# 18M 1.1 ( 1.2 slt' 18M Dens!t' $oros!t' curve !s "er!ve" )rom %ove eAut!on8ULG DENSITY INTER+RETATION ( 2 Rerrn,!n, t#e eAut!on ,!ves +OROSITY D mab = ma f l 2BI *#rts +OR(B 6S7 +OR(10 6;7 2.?1 ,2cc8ULG DENSITY INTER+RETATION ( ? T#e "ens!t' correct!on 6 ) curve !s Dmesurement Aul!t'E +oor $" contct ,!ves > 0.0B O)ten correltes &!t# cl!$er I) correct!on C 0.20 ,2cc 8ul- "ens!t' curve !s !nvl!" CAL +,-./ , 0,-./+;OTOELE*TRI* INTER+RETATION ( 2 +;OTOELE*TRI* INTER+RETATION ( 1 T#e +e vlue 6!n %rns2electron7 !s t#e &e!,#te" sum o) t#e mtr!3 n" )lu!" c$ture cross sect!ons ( ) * e P e ma maP e+ e Pef l f l= ( ) * e + ema fl T'$!cl Vlues Mtr!3 +eF 1.H SS9 B.1 LS9 ?.1 DOL Mtr!3 e Pe: 4.H SS9 1?.H LS9 0 DOL Flu!" e Pe: 0.1 ( 0.J O8M n" )res# 18M 0.J < 1.0 slt' 18M +;OTOELE*TRI* INTER+RETATION ( 2 T#e lo,,!n, curve !s +e T#e $ro"uct ePe 4 U/ c$ture cross(sect!on2cc U= ( ) * Uma+ Uf lT#!s loo-s l!-e t#e "ens!t' eAut!on 1e "on>t solve )or %ecuse U)l KK Um See A$$en"!3 J *#rts )or vlues o) +e+;OTOELE*TRI* INTER+RETATION ( 2 TY+I*AL FORMATIONS 2 RHOB 3 0 PEF 10 Mtr!3 vlues L!mestone 5!1 2!"1 Dolom!te 2!#"3!1 Sn"stone 1!# 2!65S*;LUM8ERGER 1IRELINE TOOL ;ISTORY Powered Gamma Tool (PGT) Litho Density Tool (LGT) Three-Detector Lithology Density (TLD) Fle1 2oint Nal(&3*Scintillation Detector Geiger+4uller Detecter Gamma Ray Source Nal(&3*ScintillationDetector Nal(&3*ScintillationDetector Gamma Ray Source Nal(&3* Scintillation Detector Nal(&3* Scintillation Detector GSO(Ce* Scintillation Detector Gamma Ray Source Fle1 2oint mab FA*TORS AFFE*TING DENSITY LOG RES+ONSE S#les n" cl's M' cuse $oros!t' re"!n, to %e too #!,# or too lo& Vsh n"s hcn %e o%t!ne" )rom lo, re"!n,s !n s#le Lones ;'"rocr%ons In o!l Lones/ h c= o!c# cn %e mesure" )rom )lu!" sm$les In ,s Lones/ h c= g!c# cn %e mesure" or clculte" us!n, ,s $ro$ert!es Gs &!ll cuse nomlousl' lo& "ens!t' n"/ t#us/ #!,# "ens!t'$oros!t'D = maftDENSITY LOG *OMMENTS GR 0 API 200 RHOB 2 G/C3 3 DRHO 0!25G/C3 0!25 CALIX 6 IN 16 CALIY 6 IN 16 4100 Dens!t' Gmm r' Dens!t' correct!on Ver' rel!%le tool Use" to "eterm!ne %ul- "ens!t' +oros!t' l!t#olo,' S#llo& "e$t# o) !nvest!,t!on ( 10 to 1B cm 4200 *l!$erI) correct!on C 0.20 ,2cc 8ul- "ens!t' curve !s !nvl!" From NE3T/ 1000NEUTRON LOGSNEUTRON LOGS Uses o) neutron lo,s I"ent!)' $orous Lones Determ!ne $oros!t' I"ent!)' ,s !n $orous Lones 1#ere neutron lo,s cn %e use" An' %ore#ole O$en or cse" L!Au!"( or !r()!lle" De$t# o) !nvest!,t!on @(12 !nc#es )or *NNEUTRON MEASUREMENT b Uses L!t#olo,' +oros!t' *ur ve PeNEUTRON TOOL +RIN*I+LE Source Am8e 1B(20*u BMeV Detects neutrons )rom t#e source !c# #ve %een scttere" %c- %' t#e )ormt!onT#e neutron tool em$lo's"ul "etector "es!,n to com$enste )or mu"c-e/ l!t#olo,'/ etc. St!ll/ correct!ons re reAu!re" )or t#e N+;I vlues NOTE F T#e tool !s $resse" ,!nst t#e %ore#ole &ll to m!n!m!Le mu" e))ectsLIFE OF A NEUTRON ( 2 LIFE OF A NEUTRON ( 1 Neutrons em!tte" )rom source Neutrons !nterct &!t# ;'"ro,en !n )ormt!on Neutrons lose ener,' Neutrons re %sor%e" or re)lecte" %c- to "etectors ;!,# counts 4 Lo& $oros!t' Lo& counts 4 ;!,# $oros!t' LIFE OF A NEUTRON ( 2 Source Am8e 1B(20*u BMeV neutrons *oll!s!ons cuse neutrons to lose ener,' Ener,' loss "ue m!nl' to #'"ro,en T#ere)ore tool mesures mount o) #'"ro,en !n )ormt!on/ !e./ &ter/ o!lLIFE OF A NEUTRON ( 2 T#erml Neutrons T#e neutron tool res$on"s $r!mr!l' to t#e $resence o) #'"ro,en T#e more #'"ro,en/ more neutrons slo&e" to t#e t#erml level n" c$ture" %' t#e )ormt!on Ot#er m!nerls lso #vesmll e))ect on t#e neutron tool/ !c# reAu!res com$enst!onNEUTRON TOOL DESIGN 8ot# "etectors $lce" !n lon, s$c!n, Lone *ount rtes t t#e "etectors re !nversel' $ro$ort!onl to )ormt!on $oros!t' n" "!stnce )rom source Ner2Fr Rt!o $ro$ort!onl to $oros!t' Rt!o com$enstes )or mu"c-eENVIRONMENTAL EFFE*TS ON N+;I L!t#olo,' E))ects T#e tool res$on"s mostl' to t#e $resence o) #'"ro,en/ %ut "!))erent m!nerls &!ll slo& neutrons to "!))erent "e,rees T#ere)ore/ t#e Neutron tool re"s "!))erent vlues )or N+;I !n "!))erent )ormt!ons o) t#e sme $oros!t' T#!s must %e t-en !nto ccount )or t#e N+;I curveNEUTRON LOG INTER+RETATION ( 1 Rt!o converte" to $$rent $oros!t'! Mn' env!ronmentl e))ects Assumes Mtr!3 Usull' LS Somet!mes SS 1ter()!lle" *#rts +OR(12((1@ *#rt vr!es &!t# toolMuest!onF Onl!mestone scle/ t#e N+;I !s 20I. ;o&ever t#e )ormt!on !s sn"stone. 1#t !s t#e true $oros!t'N Ans&er F 2BI.GAS EFFE*TS ON N+;I Gs #slo&er #'"ro,en concentrt!on t#n o!l or &ter "ue to !t>s lo&er "ens!t' A neutron tool !nter$rets ,s to %e &ter occu$'!n,smller volume9smller volume menssmller $oros!t' ;ence !n ,s Lones/ t#e neutron tool re"s nomlousl' lo& $oros!t'NEUTRON LOG INTER+RETATION ( 2 Re"s "ee$er t#n "ens!t' More ))ecte" %' v!r,!n Lone )lu!" Gs e))ect Gs lo&ers ; concentrt!on/ lo&ers $$rent $oros!t' N51B52150(? Gs e))ectGAS EFFE*T Not!ce t#e N+;I re"!n, !s less !n,s Lone t#n !n n o!l Lone !n t#e sme l!t#olo,' In,s Lone/ N+;I re"s too lo& n" D+;I re"s too #!,# T#e 2 curves trc- closel' !n o!l(sturte" LoneS;ALE EFFE*TS ON N+;I S#l!ness ))ects neutron $oros!t' S#le #s %oun" &ter !n ltt!ce structure T#!s &ter !s !mmo%!le n" "oes not re$resent EFFE*TIVE $oros!t' ;o&ever/ t#e neutron tool res$on"s to t#e $resence o) #'"ro,en !n t#e %oun" &ter o) s#les/ n" t#e neutron tool re"s nomlousl' #!,# N+;INEUTRON LOG INTER+RETATION ( ? S#le e))ect Res$on"s to %oun" &ter Ec# +;IN "!v!s!on 4 ?I 0 +or. 4 ?0I S#le e))ectNEUTRON S;ALE EFFE*T +EF Sn" < *len O 1.H Sn"