Sequential extraction—a useful tool for reservoir geochemistry?

0r9. 6e0chem. V01.2~ N0. 12 pp. 1157 117L 1996 C0pyr19ht • 1996E ~ e ~ 5~en~ Ltd Fr1n~d1n6~m 8r1tMn.A11F9ht5~ e d P1~ 50146-6380(96)00100-3 014~6~96 $15~0 + 0.00

5e4uent1a1 extract10n--a u5efu1 t001 f0r re5erv01r 9e0chem15try• A. W1LHELM~*, 1. H 0 R 5 7 A D ~ and D. KARL5EN ~ ~Dep~tment ~f 6e~09L U ~ r 5 1 f f 0f 0 ~ P. 0. 80x 1047, 0316 0510, N0rway and ~5a9a P~r0Mum A.5., P. 0. 80x 490, 1301, 5and~ka, N0rway A65~act--L1tt1e 15 kn0wn a60ut the m~r05ca~ d~tf16uf10n and p0tenf1M m01ecu1ar ~a~10nat10n 0f 61tumen re51d1n91n re5erv01r r0ck~ Few data e~5t 0n the c0mparat1ve 0r9an1c 9e0chem1~ry 0f hydr0car60n5 1n auth19en~ 1ndu~0n5 f0rmed 1n re5erv01r r0ck5 and the ~tumen 1n the p0re 5pac~ A three 5~p 5e4uent1~ extract10n ~chn14ue ha5 6een app11ed ~0 d~5f1c petr0~um re5erv~r 5am~e5, u~n9 a 5u1~ 0f 501xem5 w1~h1ncrea51n9p01ar1ty, ~ 0rder t0 addre~ the5e 4ue5t10n5. 1n the an~y2ed 5amp1e5 the f0110w1n9 ma1n trend5 were 065erved: (1) the f1r5t extract repre5ent5 >95% 0f the t0t~ ex~ac~ (11) the rdat1ve p01ar c0mp0und c0ntent 1ncrea5e5 9~n9 ~0m the f1~t t0 the ~ extra0; (111)the ~ a extraa ha5 9 e n e r ~ a 5119ht1y10wer apparent matur1ty a5 a~e~ed u~n9 ~0marker param~er5. Add1f10n~ a reduct10n 1n the de9ree 0f 610de9radat10n ~0m the f1r~ t0 the 1a5t extract5 wa5 065erved, 1mp1~n9 ~ntat1vdy that 610de9radaf10n take5 p1ace d0m1nant1y1n the center 0f the p0re5. F1u1d 1ndu~0n extrac~ 5h0w d15t1n~ 50urce charac~f15t1c5, h0wever the ~5t extract appear5 t0 appr0ach the f1u1d1nc1u~0nextract ~9nature 1n 50me a5pec~. 7he u5e 0f 5e4uent1a1extract10n a5 a r0ut1ne t001 1n the re5erv01r 9e0chem~ c0n~xt 15jud9ed t0 6e f1m1~d: h0wew~r 1t may hdp t0 50he 5pe0f1c pr06~m5. C0pyr19ht • 1996 E15e~er 5~ence Ltd Key w0rd55e4uenf1~ extract10n, f1~d 1ndu~0n~ ~ r

~7R0DUC7~N

~0c~m15try

marker matur1ty rat10~ ha5 6een 065erVed (Pr1Ce and Chyt0n, 1992; 6hen1m~ 1993). 5e4uent1M exffact10n ~ud1e5 have 6een rep0~ed f0r Here a 5y5~mat1C ~5t 0f the U5efU1ne~ 0f 5e4uen50urce r0ck5 (5~90 et a1., 1983; 5p1r0, 1984; Pr1ce t1~ extract10n 1n re5erv01r 9e0chem1ca1 ~ud1e5 0f and Chyt0n, 1992~ c0a15 (L0ve et a1, 1991) and d1f1n~9ra~d 5and5t0ne5 wa5 at~mp~d. re5erv01r r0ck5 (6hen1m~ 1993; W11hdm5, 1993). Add1t10na11y 1he re5u1~ 0f petr01eum f1u1d 1nduf10n 5e4uent1~ extract10n ~ u d ~ uf1n9 the 5ame 501vent an~yf1~ f0r a 5u65~ 0f the 5amp1e5, were c0mpared thr0u9h0ut, were perf0rmed 0n uncru5hed r0ck t0 the re5pect1ve re5uR5 ~0m 5e4uent1~ extract10n. w1th d1fferent durat10n 0f ex~act10n (Pr1ce and 7he ~art1n9 p ~ n t f0r th15 w0rk wa5 a h19h1y f1mC1ayt0n, 1992), c0m61n1n9 extract10n 0f uncru5hed pf15t1c c0nceptu~ m0dd f0r petr01eum accumuand cru5hed r0ck5 (5~90 et a1., 1983) 0r emp10~n9 ht10n 1n p0r0u5 med1a; 1.e. the 0n10n 5~n m0de1 ex~act10n 6ef0re and a~er 5dect1ve m1ner~ d1~01- (F19. 1). ut10n (5p1~0, 1984). 1t 15 a55umed that 50me 0f the p0~r c0mp0und5 Re5erv0~ r0ck ~ud1e5 u51n9 5e4uent1~ extract10n 0f the f1r~ petr01eum char9e en~r1n9 a 5and~0ne have 6een hm1ted t0 a f1n91e 5amp1e (6hen1m~ re5erv01r ad50r6 0nt0 the m1nera1 5urface~water 1993) 0r t0 9ra1n f12e ~act10n5 ~0m tw0 5amp1e5 ~ye~. Later p~r01eum char9e5 have t0 ad50r6 0n (W11hdm5, 1993). 6hen1ma (1993) f0und a trend 0f t0p 0f the 1n1t1a1p01ar ~yer (th15 ad50rpt10n ~ en~decreaf1n9 matur1ty 1n 0ne tar mat 5amp1e u~n9 a 5a9ed t0 6e weaker c0mpared t0 the p01ar c0mtw0 5~p extract10n. W11hdm5 (1993) aud1ed 9ra1n p0und-m1nera1 5urface 1n~ract10n). Dur1n9 th15 f12e ~act10n5 ~0m 0ne 011 ~9 and 0ne tar mat pr0ce55 hydr0car60n5 are trapped/0cc1uded 1n the p 0 ~ r mater1~ (8ehar and Vanden6r0ucke, 1988). 5amp1e ~hree 5~p ex~act10n) and 065erved matu~ 8y 1ncrea~n9 the 5tren9th 0f the 501vent5 1ty and fa~e5 var1at10n5 6etween the 5e4uent1~ emp10yed 1n 5e4uent1~ extract10n 1t m19ht 6e p055ex~ac~ and 6etween the 9ra1n f12e ~act10n~ A11 0f 161e t0 rec0n~ru~ the re5erv01r f1111n9 h1~0ry, the a60ve ment10ned ~ud1e5 n0t1ced a rap1d acc0rd1n9 t0 the f1r~ ~ - ~ 5 t 0ut hyp0the51~ wh1ch decrea5e 1n the extract10n f1dd and a rdat1ve 5tate5 that the f1r5t p ~ r 0 ~ u m enter1n9 a p0re w1~ 1ncrea5e 1n the percenta9e 0f p 0 h r mater1a1 1n the 1nteract m05t 5~0n~y w1th the m1ner~ 5urface~ the 5ucce551ve extract~ 1n 50me ca5e5 a decrea5e 1n the 5u65e4uent p~r01eum 1nteract1n9 w1th th15 1n1t1~ rdat1ve apparent matur1ty, a5 a55e55ed 6y 61010~c~ petr0~um. Wherea5 d1ffu510n pr0ce55e5 w0u1d n0rma11y *Pre5ent addre~: N0r5k Hydr0 Re5earch Cen~L N-5020 rem0ve 1n1t1~ d1fference5 1n 5aturated and ar0mat1c 5and511, N0rway. hydr0car60n ~act10n5 0n a 5u6 metre 5c~e ~ 1157

1158

A. W1~m5 et aL

0n

n 5k1n M0

1

R~er~r ~n9 m ~ 1 ~

~f1~ ~ ~

~4u~f1~ ~ a ~ 1nc~0n E0M-3

nc~0n [ ~ ach~9e te ~t ~ ~

E0M-2 E0M-1

nerN

1a5t 1n -f1r5t 0ut F19. 1.7he ••0n10n 5k1n m0de1••--a 5chemat1c c0nceptu~ v15ua112at10n 0f pr09re~1ve 011 char9e5 f1111n9 a p0r0u5 netw0rk. En91and et a1., 1987), R wa5 p05tu1ated that c0mp0und5 ~apped/0cduded 1n p01ar c0mp0und5 ad50r6ed 0nt0 m1ner~ 5urface5 c0u1d perhap5 ret~n 50me 0f t h 0 r f1111n9 rdated d1fference5, due t0 th0r h1ndered m06111ty. 5 a m p ~ 5et

5amp1e5 fr0m f0ur d1fferent petr01eum 5y~em5 were 5dec~d. 7he f0ur d1fferent 50urce/re5erv01r 5y5tem5 repre5ent t0ta11y d1fferent re5erv01r5 and petr0~um f1111n9 5y~em5 ff0m the N0rwe#an N0rth 5ea, w1th depth5 ran91n9 ff0m ca. 1600 m t0 3600 m (F19. 2; 7a61e 1). 5h0rt de5cr1pt10n5 0f the ~ud1ed f1dd5 are 91ven 6e10w. ~ 0 H F1eM

7he 7 r ~ ~ d d ~ p r e ~ n ~ a 5 h ~ 0 w 9a5 and ~1 ~rv~r 1n Upper Jura5~c 5and~0ne~ where ~ 1 n 9 p r 0 6 a ~ y 5tarted 1n Eaf1y 7 e ~ a r y t1me5 and ~ 5~1 act1v~ 7he re5erv01r5 are 6uffed t0 ca. 1600 m, and are uncememed. At pre5enL the 7r0H ~ d ha5 a t ~ n ~1 ~9 ~ - 2 2 ~ 6e~w a t ~ c k 9a5 c~umm 7he h c k 0f ~9~f1cant re~dua1 ~ ~ n 9 ~ the 9a5 cap, 5u99e5t5 that the re5erv~r wa5 ~ e d ~ t h a ~vdy dry 9a5 pr10r t0 ~1 char~n9. 8 d 0 w the current ~1 ~9, there 15 a wed9e ~ a p e d re~duM ~ 20ne, 5u99e5t1n9 a recent t1~n9 0f the f1dd ~ 0 r 5 t a d and La~e~ 199~.

7he n0rthern part 0f the f1dd appear5 t0 c0nt~n a m1xture 0f a 610de9raded and a f1e5h 011 char9e. A9at F1eM

7he A9at F1dd 15 a 9a5/c0nden5ate d15c0very 1n Cretace0u5 5and5t0ne5 0n the ea5t f1ank 0f the 509n 6ra6en. 7he re5erv01r 15 6ur1ed t0 a p p r 0 x 1 m a ~ 3600 m and petr01eum f111ed f1u1d 1nduf10n5 w1th1n 4ua~2 0ver9r0wth5 are c0mm0n. 7he A9at F1dd ha5 pr06a61y rec~ved petr0~um char9e5 at 5ever~ ~a9e5 w1th 1ar9e var1at10n5 1n t h 0 r 9a5-011 rat10. 7he current accumu1af10n5 c0nt~n m~n1y 9a5 and c0nden5a~, 6ut ref1du~ 011 ~a1n1n9 1n the c0red 1nterv~5 5u99e5~ that 011 ha5 6een pre5ent 1n 50me 0f the 5and5t0ne5. 7he c0re extract5 are heav11y 61a5ed t0ward5 10n9 ch~n n-a1kane5, wh1ch m19ht repre5ent a re~due a~er evap0rat1ve f1act10naf10n (7h0mp50n, 1991). U1a F1e1d

7he U1a F1dd 15 10cated 1n the C e n ~ 6ra6en. 7he re5erv01r5 are 0f 7r1a5~c and Upper Jura5~c a9e, 6ur1ed t0 appr0x1matdy 3500 m. 7he re5erv01r ha5 a re1at1ve1y h19h de9ree 0f d1a9ene5~, w1th ~9n1f1cant 4ua~2 cementat10n. F1u1d 1ndu~0n5 are f0und 1n K-fe1d5paL p1a9100a5e and 4 u a ~ 7he d1fferent m1nera1 pha5e5 have ~apped petr01eum w1th d1fference5 60th 1n matur1ty and 50urce r0ck fa0e5 (Kar15en et a1., 1993; Nedkv1tne et a1., 1993).

5e4uent1a1 ex~acf10n--a u5efu1t001 f0r re5erv~r 9e0chem~ffy

1159

We1110cat10n5

F19. 2. We11~cat10n map 0f ~ud~d wd15. 5n0rre F1eM

7he 5n0rre F1dd repre5ent5 a ~ a n t accumu1at10n 0f under5aturated 61ack 011 w1th a 9a5-011 rat10 vary1n9 6etween 80 and 220 5m3/5m3. 7he accumu1at10n ~ w1th1n Upper 7f1a5f1c t0 L0wer Jura5f1c 5and5t0ne5 at a depth 0f ca. 2550 m. 7he de9ree 0f d1a9enef15 15 rdat1vdy m11d w1th m1n0r 4ua~2 cementat10n. 011-011 and 0~-50urce r0ck c0rre1at10n5 5u99e5t that the 5n0rre F1dd 0115 are der1ved fr0m the 6af1n t0 f1ae n0rth 0f the f1~d, w1th 0~

char91n9 fr0m La~e C~etace0u5 unt11 pre5ent. 7he 5amp1e fr0m the 5n0rre F1e1d wa5 u5ed f0r a repr0duc16111ty te5L thu5 e5ta6115h1n9 err0r 6ar5 f0r the 0ther 5amp1e 5et5

EXPER1MEN7AL

D1f1me9~cru5hed ~ r 5and5t0ne ~ m ~ were ~4uent1a11y extracted ~ a 50xtec extract10n u ~ t ~ee f10wcha~; F19. 3).

7aNe 1.5am~e ~ c ~ n , w ~ name and num6~ 0f ~mp~5 ~ud~d per w ~ ~dd

W~

N0.0f ~m~

7r~1

31/2

5

A9at

3~3-2

5 (p1~ 1 du~e

U1a

~1~6

1

3~7A-9H

1 (f1x f1m~)

5n0rm

Rem~ 5ha110w f1dd; p0551~e m1~n9 0f 610de9raded and ff~h ~1 deep ~ f1~d ~du~0n5 deep re5erv01~ mu1t1p1ef1~d 1ndu~0n 9enerat10n5 and ~5erv01r f1111n9pha5e5 ~pr0du~11ff ~

1160

A. W11hdm5et

aL

Expef1ment H0wchart

CrU5hed5amP ~R0ck1 1

~r~1ty ~d ~rme~ me~u~ment5 fr0m adj~em c0re p1u~ ~1~m~mc~

DCM ~ ~

ex~ct

1

extract

CHC13

~ 7HF:DCM:Me0H

~

~

6CM56C•

~

~

6CM56C•

exffact

E0M-3

5~4~3 ~ v

exUacted5amP 1er°ck1

~

~M5

XRD • 7 0 C

F19. 3. Expef1menm1f10wcha~.

7he f1r5t extract (E0M-1) wa5 06ta1ned ufn9 d1ch10r0methane (DCM; 20 m1n 60111n~ 40 m1n r1nfn9), f0r the 5ec0nd extract (E0M-2) ch10r0f0rm wa5 u5ed (CHC13, 1 h 60111n9; 1 h f1nfn9) and f0r the th1rd extract (E0M-3) a m1xture 0f ~Uahydr0furan, d~h10r0methane and methan01 wa5 emp10yed (7HF:DCM:Me0H 50:47:3 v:v:v; 1 h 60111n~ 2 h f1nfn9). P0r051ty and permea6111ty data were taken fr0m c0re p1u9 mea5uremen~ 1n the 5ame f1th0109y 1n the d1rect v1dn1ty 0f the ana1y2ed 5amp1e5 (< 10 cm d1~ance). M1nera1091ca1 c0mp0ft10n5 were determ1ned u51n9 XRD. 7 0 C and R0ck-Eva1 data were determ1ned 0n 5dected 5amp1e5 after extract10n. 1n~rna1 5tandard5 (54ua1ane and 5~(H)andr05tane) were added t0 the extract5. 6r055 c0mp051t10n wa5 de~rm1ned u51n9 a ~ 0 ~ can 7LC-F1D aparatu5 (Kar15en and La~eL 1991). Preparat1ve extract5 were 5eparated 1nt0 9r0up type5 0n m1n1c01umn5 a5 de5cr16ed 1n Lafar9ue and 8ehaL 1989. 7he 5aturated hydr0car60n fract10n5 were ana~2ed 0n a F150n5 MD800 6 C - M 5 5y~em (e4u1pped w1th a 50 m fu5ed 511~a cap1~ary c01umn, 0.25 mm 1.d., c0ated w1th a 0.25 Vm f11m 0f D85M5 pha5e). 7he c01umn wa5 had at 80°C f0r 1 m1n, then temperature pr09rammed at 10°C/m1n

t0180°C, f0H0wed 6y a temperature 0f 1.7°C/m1n t0310°C and he1d there f0r 30 m1n. F0r the 5aturated hydr0car60n fract10n5 a Vaf1an 35006C e4u1pped w1th a 25 m fu5ed f11ca capf11ary c01umn (0.25 mm 1.d., c0ated w1th 0.25 ~m f11m 0f D8-1 pha5e) wa5 u5ed, w1th the f0110w1n9 temperature pr09ram: 1n1t1a1 temperature 70°C (2 m1n h01d t1me), then temperature pr09rammed at 4.5°C/m1n t0310°C w1th a f1na1 h01d t1me 0f 20 m1n. Repr0duc161f1ty ha56een a55e55ed 6y ana1y~n9 the 5amp1e fr0m the 5n0rre F1dd (we1134/7A-9H) f1x t1me5, 1.e. aH ~ep55tart1n9 w1th extract10n. 6enera11y the repr0duc161f1ty f0r 9r055 c0mp0ft10na1 data and c0mp0und rat10515900d, h0wever f0r E0M-2 and E0M-3 the repr0duc16111ty 0f the ••4uant1tat1ve•• 6101091ca1 marker data ~ very p00r (7a6~ 2). Err0r 6ar56a5ed 0n the repeat ana1y5e5 are 1nduded.

RE5UL75ANDD15CU5510N M0re than 95% 0f the t0ta1 extract y1dd 15 extracted 1n the E0M-1 (F19. 4; 7a61e 3). 7h15 1mp11e5 that n0rma1 extract pr0cedure5 are ade4uate t0 c0nf1denf1ycharacter12e E0M. 7he re1at1ve a6undance 0f 5aturated hydr0car60n5 9enera11y decrea5e5

5e4uenf1~ ex~act10n--a u5efu1 t001 f0r re5erv01r 9e0chem~y

1161

7a~e 2. Repr0du~f1~ a5~ment f0r var10u5parame~ 0vera9e and ~andard dev~f10n) 6a~d 0n ~x an~y5156am~e ~0m wd1 3~ 7A-9H, 5n0rre F~1d, 5ee Append~ 8 f0r ex~anaf10n 0f a66~f1af10n5) Repr0du~61f1ty ~ a , avera9e and 5tandard de~af10n 6a5ed 0n ~x repeat an~y~5 extract n0. E0M-1 E0M-2 E0M-3

avera9e cr avera9e 9 avera9e ~

ex9act n0. E0M-1 E0M-2 E0M-3

avera9e ~ avera9e ~ avera9e ~

ex~act n0. E0M-1 E0M-2 E0M-3

avera9e a avera9e a avera9e a

E0M-2 E0M-3

5at%

ar0%

re5%

5at H C (rn9/9 r0ck)

ma1kane5 (~9/9 ~0ck)

n-~kane5 (~9/m9 5a~

52.22 0.78 0.70 0.13 0.52 0.05

37.0 1.0 6,9 0,7 2.4 0.8

58.9 1.0 4.9 2,2 1.2 0.9

4.1 0.3 88.2 2.8 96,4 1.7

19.33 0.66 0.05 0.01 0.01 0.01

1836.53 371.40 8,99 7.07 1.62 1.54

95.00 18.98 167.05 103.52 113.40 98.68

C ~ ~erane5 (n~9 r0c~

C30 h0pane ( n ~ 9 r0ck)

C~ ~mn~ ~ m 9 5at)

C ~ h0pane ( n ~ m 9 5at)

P~Ph

P~nC17

P~nC18

7513 667 46 38 13 8

1~506 1264 84 72 24 16

389 33 841 573 1009 563

647 70 1542 1096 1860 1004

1.49 0.03 1,44 0.04 1.43 0,10

0.77 0.03 0.69 0.04 0.71 0.12

0.58 0,04 0.53 0.04 0.51 0,11

n-C17• (nC17 + nC27)

C27% ~205

C28% ~205

C29% ~205

C27d1a 5/(5 + R)

205/(205 + 20R)

0,77 0.02 0.72 0.05 0.72 0.03

40.57 1.06 38.14 1.11 39,03 0.99

27,69 0,93 28.68 0.97 27.41 1.21

31.74 1.55 33.18 0.75 33.56 0.79

0.62 0.02 0.66 0.04 0.70 0.05

0.46 0.01 0.45 0,01 0.46 0.02

0.59 0,01 0.58 0.01 0.59 0.01

d1a/n0rh0p

8NH~n0rh0p +h0p)

0.26 0.01 0.28 0,04 0.24 0.02

0.23 0.01 0.23 0.01 0.19 0.03

22/5 7E7• (225 + 22R) ( 7 E 7 + C237)

extract n0. E0M-1

E0M (m9/9 ~0ck)

avera9e 9 avera9e ~ avera9e ~r

0.60 0.01 0.61 0,00 0,61 0.01

0.38 0.02 0.36 0.02 0.32 0.02

m0r/h0p 0.09 0.01 0.09 0,01 0.09 0.01

ff0m 55-70% 1n E0M-1 t0 10-15% 1n E0M-2 and t0 1e55 than 4% 1n E0M-3 (F19. 4). 7he re~t1ve c0ncen~at10n 0f p01ar c0mp0und5 0.e. re~n5 and a 5 p h ~ n e 5 ) 15 >90% 1n the 1a5t extract (E0M-3). 7he f1u1d 1ndu~0n5 extract5 have 6een 5h0wn t0 6e heaf11y enr1ched 1n p01ar c0mp0und5 (Kar15en, 1992). 7he extract f1dd decrea5e5 6y tw0 0rder5 0f ma9n1tude ff0m f1r5t t0 5ec0nd extract. 7h15 5u99e5t5 that DCM and CHC1~ are extract1n9 a ~m11ar "~yer~. 7he 7 H F : D C M : M e 0 H extract f1dd (E0M-3) 1ncrea5e5 a1m05t tenf01d c0mpared t0 E0M-2. 7h15 5u99e5t5 that a d1fferent ~ y e f ~ 15 extracted 6y th15 50Nent m1xture (F19. 1). 7here d0e5 n0t appear t0 6e a c0rrdat10n 6etween ex~act y1dd and c0mp0~f10n 0f the extract5 w1th 6u1k m1nera109y 0r p0r0~ty/pe~ mea61f1ty (7a61e 4). H0wever 1t ha5 t0 6e p01nted 0ut that the petr0phy~c~ da1a ate n0t der1ved ff0m ana1y~5 0f exact~ the 5ame 5amp1e5, 1.e. var1at10n5 1n the petr0phy~c~ pr0pert1e5 6etween 0r9an1c 9e0chem1c~ and pe~0phy51ca1 5amp1e5 can n0t 6e c0mp1ete~ ru1ed 0ut. 8a5ed 0n the a v ~ 6 1 e 4uant1tat1ve 610marker data, m0re than 99% 0f the t0t~ extracted na1kane5 and 61010~c~ marker5 (per 9ram r0ck) are

75~75 + 7m) C2975/n0rh0p 0.62 0,01 0.62 0.01 0.61 0.01

0.44 0.04 0.43 0.03 0.42 0.03

~/(~

+~)

1n the f1r5t extract (E0M-1). 7he c0ncentrat10n5 0f n-a1kane5 and 61010~c~ marker5 1n the 5aturated hydr0car60n ~acf10n (per m9 5aturated hydr0ca~ 60n~ are f1mf1ar 1n aH extract5 c0nf1def1n9 the uncert~nty 0f 4uant1f1cat10n 00w y1dd5 1n 5ec0nd and th1rd ex~ac~ E0M-2 and E0M-3; 7a6~5 3 and 5). 7here 15 a 9enera1 trend 0f decrea~n9 apparent matur1ty ~0m E0M-1 v1a E 0 M - 2 t0 E0M-3 (F19. 5, 7a61e 6). Wh11e 50me c0rtf16ut10n5 ~0m 1nd19en0u5 0r9an1c matter can never 6e c 0 m p 1 e ~ ru1ed 0ut, we c0n51der th15 t0 6e a m1n0r pr06~m, a5 the p05t extract10n 7 0 C and R0ck-EvM va1ue5 are ne9f1~61e f0r the A9at and 5n0rre F1e1d 5amp1e5 (7a61e 46) and a5 the fa5t extract5 are 0n1y 5119ht1y ~55 mature 1n the 5h~10w 7r011 F1dd 5amp~5 0.e. the temperature 15 t00 10w f0r petr01eum 9enerat10n ff0m 1nd19en0u5 0r9an1c matte~. 1n 9eneral the 4ua11ty 0f p0~nf1~ mace am0unt5 0f 0r9an1c m a t ~ r pre5ent 1n 5and5t0ne5 15 expected t0 ref1ect the h19h ener9y dep0f1t10n~ 5ett1n~ 1.e. part1y 0x1d12ed ker09en5 hav1n9 10w hydr0car60n 9enerat10n p0tent1a1. 7he de9ree 0f 610de9radat10n 1n the 7r011 F1dd 5amp1e5 appear5 t0 decrea5e 5119ht1y ff0m E0M-1 t0 E0M-3 6a5ed 0n 150pren01d/n-a1kane rat105 and the

1162

A. W1~e1m5 et a1.

5e4uent1a1 e ~

y1e1d5

0

~

~

1 ~ m ~ a ~ ~

9 J

E0M- 1

E0M-2

E0M-3

1~=~ ~ ~ ~" ~;1 ~1 ~" ~" ~" ~" ~ 31/2-6

7/12-6

35/3-2

Re1at~e 9r055 c0mp05~0n

wa1f 3112-6, 1570.0m

40~"

1

2

3

F19. 4. Ex~act ~dd5 and extract c0mp0f1t10n f0r 5e4uent1a1 extract5, 111u~raf1n9 the 5harp decrea5e 1n extract ~ d d and the 1ncrea5e ~ the r~at1ve p01ar c0mp0und c0ncentrat10n.

5e4uent1a1 e x ~ a c t 1 0 n - - a u5efu1 t001 f 0 r re5erv01r 9 e 0 c h e m 1 ~ r y

1163

7 a N e 3. E x ~ a ~ ~ d d 5 and 9 r 0 ~ c0mp0f1f10n 0f ~ u ~ e d ~ m p ~ 5 We11

Depth (m)

Extract

E0M (m9/9 r0ck)

5at%

ar0%

re5%

31/2-6

1570.0

E0M- 1 E0M-2 E0M-3

15.11 0.13 0.88

55,1 14.9 1.2

22.3 0.5 0.0

22.6 84.6 98.8

31/2-6

1575.0

E0M-1 E0M-2 E0M-3

15.88 0.13 1,18

54.2 40.7 0.9

20.5 7.4 0.4

25.4 51.9 98.7

31,/2-6

1584.8

E0M-1 E0M-2 E0M-3

6.19 0.11 1,17

57.9 29,1 1.5

23.7 1.2 1.7

18.4 69.8 96.8

31/2-6

1598.9

E0M-1 E0M-2 E0M-3

17.18 0.16 0.77

57.7 15.9 2.0

26.5 1.4 7.2

15.8 82.6 90,8

31,/2-6

1610.8

E0M-1 E0M-2 E0M-3

0.35 0.05 0.57

54,6 15.9 3.3

12.6 19.9 3.8

32,8 64.1 92,9

7/12-6

3429.8

E0M-1 E0M-2 E0M-3

8.64 0.10 0.41

68.6 10.0 3.6

17.2 0,05 0.0

14.1 89.6 96.4

35/3-2

3594.8

E0M-1 E0M-2 E0M-3

9.93 0.32 3.54

60.8 14.4 4.2

25,6 4,0 0,4

13.6 81,7 95.3

35/3-2

3594.8

E0M- 1 E0M-2 E0M-3

10.02 0,33 3,65

63.6 14.1 3.2

24,9 3,6 0.5

11.4 82.3 96.4

35/3-2

3597.5

E0M-1 E0M-2 E0M-3

7,65 0.25 0,37

63,4 16,7 3.0

26.2 5.1 0.0

10.4 78.2 97.0

35/3-2

3600.9

E0M-1 E0M-2 E0M-3

5.75 0.19 1.71

66.7 12,3 2.2

22.8 1.5 0.0

10.5 86.2 97.8

35/3-2

3604.4

E0M-1 E0M-2 E0M-3

6.04 0.22 3.23

65.0 14.1 2.3

23.5 1.8 0.0

11,5 84.1 97,7

35/3-2

3708,0

E0M-1 E0M-2 E0M-3

8.39 0,29 0.35

70.7 11.3 1.8

20.3 1.8 0.0

9.0 86.9 98.2

34/7A-9H

2558.9

E0M-1 E0M-2 E0M-3

52.22 0.70 0.52

37.0 6.9 2.4

58.9 4,9 1.2

4.1 88.2 96.4

7a61e 4. (a) M1nera109y determ1ned 6y X R D fr0m 6u1k 5amp1e5 1111teand m1ca

Ka011n1te

Quart2

We11

Depth (m)

A 1 k a 1 1 P1a910c1a5e fe1d5par

3/12-6 3/12-6 3/12-6 3/12-6 3/12-6

1570.0 1575.0 1584.8 1598.9 1610.8

1.8 2.2 3.7 2,7 0.0

6.6 2.2 6.2 6.3 4,2

67.6 78.6 69,9 71.5 73.2

13.7 11.3 13.1 13.3 12.0

4.5 2.6 1,8 1.9 2,0

7/•12-6

3429.8

0.0

0,4

82.9

8.4

35/3-2 35/3-2 35/3-2 35/3-2 35/3-2

3594.8 3597.5 3600.9 3604.4 3708.0

2.1 0.0 1.5 2.3 2.4

3.5 2.5 2.6 2.7 5.9

78.5 78,5 82.9 83.6 77,4

34/7A-9H

2558,9

2.4

10.9

26.0

Ca1c1~e

D010m1te

51der1te

Pyr1te

0.3 0.8 1.7 1.9 0,2

1.8 1.1 0.6 1.0 2.4

1.1 0.6 1.4 0.4 1,4

2.6 0.6 1,6 1.0 4.6

4,4

2.4

1.2

0.3

0.0

6.8 4,6 4.8 4,2 0.0

8,3 12.7 7,5 6,1 11,9

0.0 0.9 0.0 1.0 0.0

0.0 0.0 0.0 0.0 0.0

0.8 0.8 0.7 0.1 2.4

0.0 0.0 0,0 0,0 0,0

21,3

31.7

0.0

6.7

1.0

0.0

1 164

A. W ~ h d m 5 et a1. 7 a ~ e • ( ~ P0r051ty and permea6111ty d ~ a ~ r ~1 ~ m ~ H0f120nt~ perm~ a ~ t y (mD)

and R 0 c ~ E v ~ and 7 0 C d ~ a aRer ex~ac~0n ~ r ~ e d

Vert1ca1 permea~ty (mD)

P0r0~ (He%)

51

~m~

W~1

Depth (m ~

3/12-6 3/12-6 3/12-6 3/12-6 3/12-6

1570.0 1575.0 1584.8 1598.9 1610,8

1~009 4093 2801 3714 109

13,794 n.d, n.d. n.d. n.d.

7/12-6

3429.8

1832

1781

21,1

35/3-2 35/3-2 35/3-2 35/3-2 35/3-2

3594.8 3597.5 3600.9 3604.4 3708.0

151 101 93 40 55

75 60 22 53 72

24.5 23,9 23.3 20.2 24.4

0.02 0.02 0.03 0.04 0,03

0.00 0,00 0.00 0.00 0.09

0.11 0.08 0.25 0.09 0,08

34/7A4H

2558,9

480

232

25.8

0.01

0.00

0,10

34.3 34.9 32,2 34.7 26.2

52

70C

vMue5 fr0m ex~a~ed r0ck5

7a61e 5. ••Quant1tat1ve" 610marker data f0r the 5tud1ed 5amp1e5 (5ee Append1x 8 f0r exp1anat10n cf a66rev1at10n5) We11

Depth (m)

3/12-6

1570,0

E0M-1 E0M-2 E0M-3

8.33 0.02 0.01

186.8 1,2 0,4

22.4 60.2 36.3

2452 12 7

4593 20 11

294 585 618

551 1014 1063

3/12-6

1575.0

E0M- 1 E0M-2 E 0 M -3

8,60 0.05 0.01

290.9 0.8 0.5

33,8 16.2 45.6

2310 15 8

3917 27 14

269 287 739

456 529 1308

3/12-6

1584.8

E0M- 1 E0M-2 E0M-3

3.58 0.03 0.02

72.6 0.5 0.9

20.2 15.8 48.6

841 8 10

1374 15 19

235 227 565

383 453 1048

3/12-6

1598,9

E0M-1 E0M-2 E0M-3

9.91 0.03 0.02

524.8 2.0 1.2

52.9 79.5 76.4

1288 20 10

1891 40 19

130 789 642

191 1571 1212

3/12-6

1610.8

E0M-1 E0M-2 E0M-3

0.19 0.01 0,02

3.0 0.9 0.2

16.0 129.1 9.1

9 1 3

14 2 5

49 174 184

74 300 276

7/12-6

3429,8

E0M-1 E0M-2 E0M-3

5.93 0.01 0.01

664,3 1,0 0.6

112.0 93.1 43.3

538 2 2

634 3 3

91 229 118

107 286 187

35/3-2

3594.8

E0M-1 E0M-2 E0M-3

6.04 0,05 0.15

511,9 3.7 1.2

84.8 79,3 7.8

2146 20 12

5570 50 3

355 432 78

923 1090 197

35/3-2

3594,8

E0M-1 E0M-2 E0M-3

6.37 0.05 0.12

535.9 4.6 1,2

84.1 96.8 10.1

1928 28 11

5007 71 33

302 586 91

786 1505 289

35/3-2

3597.5

E0M-1 E0M-2 E0M-3

4.85 0.04 0.01

413.4 4.3 0.6

85.2 101.9 52.1

1381 27 4

3286 71 11

285 640 348

677 1681 976

35/3-2

3600.9

E0M-1 E0M-2 E0M-3

3.83 0,02 0,04

347.5 2.7 0,4

90.6 113.9 10.4

832 14 3

1991 40 8

217 610 68

519 1676 205

35/3-2

3604.4

E0M-1 E0M-2 E0M-3

3.93 0.03 0.07

315.8 3.2 0.8

80.5 101.8 11.1

955 19 5

2199 53 15

243 594 65

560 1676 196

35/3-2

3708.0

E0M01 E0M-2 E0M-3

5.93 0.03 0.01

684.8 5.6 0.4

115.4 170.4 61.9

1255 8 1

4189 29 3

212 253 176

706 884 520

34/7MH

2558.9

E0M-1 E0M-2 E0M-3

19.33 0.05 0.01

1836.5 9.0 1.6

95.0 167.1 113.4

7513 46 13

12,506 84 24

389 841 1009

647 1542 1860

Ext~act

5at HC (m9/9 r0ck)

n-A1kane5 (~9/9 r0ck)

n-A1kane5 (~9/m9 5a0

C295terane5 C30h0pane C295terane5 (n9/9 ~0ck) (n9/m9 r0ck) (n9/m9 5a0

C30h0pane (m9/m9 5a0

5e4uenf1~ ex~act10n--a u5efu1 t001 f0r re5erv01r 9e0chem~try

7m11F~d 1570

~575 • •

1~.8

1~5

•

1570

•

0

• 161~8

•

161~8

•

~

. . . . . . . . . . . . . . ~40

~45

, ....

~50

~ ....

ff55

~60

, .... 0~5

0 . 7 0

C297Mn0~0p A9at F~

3~08 ~ 0~0 ~

•

~40

vvv~11~ 1

3708 ~

0.30

0 . ~

~

0.20

~

. . . .

~25

~

ff~

. . . .

~

. . . .

ff35

t

. . . .

040

~

. . . .

~45

~

ff~

. . . .

~

. . . .

~55

~

. . . .

~60

~

. . . .

~65

0.70

~9. 5. ~ 8 ~ c ~ m~k~ ~d m~u~y ~mem ~ r the m4uenf1~ extract5 ff0m the 7 r ~ ~dd. ~ ~0~1 m ~ k ~ 6~ed m ~ u ~ y ~ m e ~ ~ r ~e m 4 ~ n t ~ extract5 and f1~d ~du~0n extract5 ~0m the A ~ t ~dd. ~ 0 ~ = 18~H~3~n0m~h0pa~/ 1 ~ 1 ~ 6 ~ ~ ~ = 15~m~ 1~. ~ % ~ ~ 1 ~21 ~ ~ .

5hape 0f the unre501ved hump 1n the 5aturated hydr0car60n fact10n 9a5 chr0mat09ram5 (F19. 6). 7h15 m19ht 5u99e5t that 610de9radat10n take5 p1ace d0m1nant1y 1n the cen~e 0f the p0re~ and that 6 a ~ ~f1a are ~ capa61e 0f de9rad1n9 the c0mp0und5 0cduded~rapped 1n the p 0 ~ r matef1~ ad50r6ed 0rt0 0r a ~ 0 d a ~ d w1th m1nera1 ~urface5 and the water f11m. F19ure 7 5h0w5 n 0 r m ~ e d 61010~c~ marker d1~ tr16ut10n5 f0r h0pane5 and ~erane5 1n f0ur 0f the 5amp1e5 fr0m the 7r0H F10d 6ee Append1x A f0r c0mp0und 1dent1f1cat10n). A1th0u9h the d1fference5 6~ween the d1fferent extract5 are 5ma11, the matur1ty 0f E0M03 5eem5 t0 6e c0n515tent1y 10wer than the matur1ty 0f E0M-1 (F19. 5a), 6eth 1n the 011 ~9 and 1n the r e ~ d u ~ 011 20ne 6e10w the current 0 W C . 7he m05t pr0n0unced d1fference5 6~ween the 5e4uent1a1 extract5 are 065erved f0r the tf1cychc ~rpane5. 1n the current 011 ~9 E0M-3 15 enr1ched 1n tr1cycf1c ~rpane~ wherea5 the 0 p p 0 ~ h01d5 true f0r the 5ampk5 D0m the re~du~ ~1 20ne (F19. 7).

1165

Jh15 15 1ntere5t1n9, a1th0u9h n0 c1ear exp1anat10n 15 apparent. H0weveL the5e trend5 5upp0rt the f1ew that the 065ervat10n5 are n0t mere1y expef1ment~ a~efact5. 1n the A9at F10d 5amp1e5 the 5aturated hydr0car60n Dact10n 9a5 chr0mat09ram5 5h0w ~9n5 0f evap0rat1ve ffact10nat10n ~ £ 7h0mp50n, 1991) 1n ~1 three extract5 (F19. 8). 7h15 1nd1cate5 0ther that evap0rat1ve fact10naf10n take5 p1ace dur1n9 5ec0ndary m19rat10n, 0r that 9a5 fact10naf10n ha5 6een capa61e 0f 5tr1pp1n9 part 0f the C~5 t0 C:~ n-~kane5 0cc1uded/trapped 1n the p01ar c0mp0und5 ad50r6ed 0nt0 m1ner~ 5urface5. 7h15 1n turn 5u99e5~ that p01ar c0mp0und5 d0 n0t trap th15 n-~kane ran9e a5 eff1dent~ a5 they ~ a p cyc11c hydr0car60n5 under 5u65urface c0nd1t10n~ at ~ a ~ 1n the 5amp1e5 ~ud1ed, ~nce enhanced r0af1ve tr1cyd~ terpane c0nten~ are 065erved 1n the th1rd extract5 (F19. 9). 7he th1rd extract5 0f the A9at F~1d 5amp~5 are 5119ht1y 1e55 mature c0mpared t0 the f1r5t extract5 (F19. 56, 7 a 6 ~ 6). C ~ a r d1fference5 e ~ 6etween the pe~0~um f1u1d 1ndu~0n5 and the 5ucce5~ve extract5, the 1nd u ~ 0 n p~r01eum 6~n9 655 mature and c0nta1n1n9 1e~ 615n0rh0pane (F195 56 and 9). 1t appea~ h0wever that the th1rd extract5 appr0ach the f1u~ 1nd u ~ 0 n 610marker ~ 9 n ~ w1th re5pe~ t0 tf1cyc~c ~rpane c0ntenL ~ 6 d t n0t w1th re5pect t0 the ~5n0rh0pane c0ntent. 7he ana~2ed 5amp~ 0f the U1a F1e1d 5h0w5 pr0n0unced d1fference5 6etween the extract5, E0M-3 6~n9 ~55 mature than the f1r5t tw0 extract5 (7a61e 6). A 9 ~ n E0M-3 appr0ache5 the 610marker charac~f15f1c5 0f the p~r01eum f1~d 1ndu~0n5 (Kaf15en et a1., 1993). A d d 1 t 1 0 n ~ the d1fference5 6etween E0M-1 and E0M-3 are m05t pr0n0unced 1n the U1a F1e1d 5amp~, e.9. 7~(75 + 7m) chan9e5 ff0m 0.70 t0 0.59 (7a61e 6). 7he 5n0rre F10d pr0~ded an a55e~ement 0f the repr0dud~hty, wh1ch wa5 f0und t0 6e 900d (7a61e 2), ex~ept f0r 1he 4uant1tat1ve ~0marker data 1n the 5ec0nd and th1rd extract. F0r the 5n0rre F1e1d 5amp~, n0 d1fference5 0uthde the repr0duc16111ty were 065erved 5u99e5t1n9 p 0 t e n t 1 ~ a 51n91e char9e f11f1n9 f0r the exam1ned p0rt10n 0f the f1e~.

C0NCLU~0N5 8a5ed 0n the r e 5 ~ f 0 m th15 5e4Uent1a1 extract10n 5tudy the f0H0w1n9 c0ndu~0n5 have 6een reached: (1) 7he f1r5t extract5 (E0M-1) repre5ent m0re than 95 wt.% 0f the t 0 t ~ extract. Le55 than 1 wt.% 0f t0ta1 610marker and n-~kane ~ 0 d 0f the 5and5t0ne5 are pre5ent 1n the 5ec0nd and th11d extract5 (E0M-2 and E0M-3). ]h15

"~0 0"~"

, . ,000~1~

~

~000

~ 0 ~0

000~ ~

~ 0 ~ 0 ~0

~000~ • ~ ~000

.000~ ~

~ 0 0 ~" " "

~ 0 0~0 . ~

~000~,..

~..~

~ ~

~-~ ~

~ ~0

.~. . .

~

~

~

~000~

~

~

~d~--~--~ ~m~d~N m ~ d- ~°

~000

~0~

~

~

~

~

~N~N

~

~

.~. . .

.

~ 0 - ~

0~-~

~0~

.

.

~

.

<

0

~+

~ • 0~0

.

.

~ ~ 0"

~ • 000

~

~ • 00~

.

~

~

~

" 0 0 ~ ""

.

~

.

~• ~ 0 0 ~

.

~ 0 0 0 ""

~

" 0 ~"0

.

~• 0 ~

.

~0~ "

" 0 0"~

~

0

~

~0~ 0 0 ~ 0 ""

"

~~ 2 ~~° ~ 0 ~ 2

2~ 2 ~ 2

~

~00 0 0 0 ••

"

~ ~ ~ ~0 0 0

0~0 0- 0 ~

0000~

~

~0000

~

~

~

~ ....... ~0

~

~~

~

0

~

~

~

~

~

0

~ ~

~~

~

~~0 0 0

+

~

~ +

~ ~ 0 "

" 0 0"0

~ ~ " "

~0~

~

~ " 0 0" ~ ~

"~~ 0~

~

~

~

~

~00~ . 0 00.0 ~ ~

0 0 ~ "" ~

"

"

d~d~--°~

•

~ °d 1

~

"

"

~ 0 0 0~~ "

"~0 0"0

0, 0 ~ ~ 0,,

~

~ ~ 0 "

" ~"

~

NN~~N~

~

~

~

N

~

N d N N N N N

NNNN

~

~

~

----~°~d~ ~ ° ~

NNN~

~ ~

~ ~- ~ 0

~ ~9 ~

~ 2°1~~-

~ e~e e e

~ee~

"

~m " ,°~,°"°~m~~00"°~~mm~00~ 0~°"-°~"" ~000mm ~ ""m, ~~-~m "°°°~m, ~00~ °°°~ ° ~" "°°°~,, ° ~ ~~ ~000~

~~° ~0 °-"~ ~~" 0""~0~e~~

5e4uent1a1 ex~act10n--a u5efu1 t001 f0r re5erv01r 9e0chem1~ry

1167

5aturated 9a5 chr0mat09ram5 5h0w1n9 a reduct10n 1n the de9ree 0f 610de9radat10n 1n the 1a5t ex~act

7r011F1eM;3~2-6;155~$m

n-C18 5td

120M-1 Ph/n-C18= 2.3 ~

~

~.~

t1me

1E0M-21 Ph/n-C18= 1.3

J f1~

1E°M-31 Ph/n-C18= ~ 6 v~

f1R ~9. 6. 5 ~ u m ~ d hydr0car60n ffacf10n 9a5 chr0m~09ram5 fr0m ~4uent1~ extract5 (7r011 F1d~ 5am~e 158C8 m) 5h0w1n9 a ~ducf10n ~ ~ e de9ree 0f ~0de9rad~10n fr0m E0M-1 t0 E 0 M 6 .

1168

A. W11he1m5 et aL

100

+=

,M ++::+1 ............ +1~+++0:0~+~

80 60 ~

40 20 0 ~

~

~

~

~

~

~

~

~

~

~ ~

~

~ ~ ~

~

~

~

~

~

~

~

~

= ~

~ ~ ~

~

c0mp0und 1dent1f1cat10n 100

0

+1 ~1 ............

1575.0m

~ ~1:~1 ............ ~1...........................

60 ~

+1

f[] E0M-1 1

80

40 20 0 ~

~

~

~

0

~

~ ~

~

~

~

~

=

~

0 ~

~

~

~

~ ~

~

=

~

~

~

~

~

~

~

~

~ ~

~

~

~

c0mp0und 1dent1f1cat10n 100

[] E0M-1 1

80

[] E0M-2 B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60

0< 0 N 0

1584.8m

.

.

.

.

.

.

.

.

.

.

.

.

40 20 0

1 ~

~

~

o

1

=

1~1 ~

~

0

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1169

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(2)

(3)

dem0n~ra~5 that the 6u1k extract ~9nature can 6e ade4ua~1y CharaC~f12ed 1n re5erv01r r0ck5 u~n9 ~andard extract10n pr0cedure5. 7he 610marker ~9nature 0f the ~5t extract (E0M-3) 15, 1n the ~ud1ed 5amp1e5, 5119ht~ ~55 mature than 0f the f1r5t tw0 extract5 (E0M-1 and E0M-2), w1th the n0ta6~ except10n 0f the 5n0rre F1e1d 5amp1e (1r0n1ca11y the 5amp~ ch05en f0r 1he repr0du~61f1ty a n M y ~ . A tentat1ve trend 0f decreaf1n9 de9ree 0f 610de9radat10n wa5 065erved 1n the 5amp1e5 ~0m the 7r011 F1dd 901n9 ~0m 1he E0M-1 t0 E0M-3, 1mp1~n9 perhap5 that 610de9radaf10n take5 p1ace d0m1nant1y 1n the centre 0f the p0re5, and that 6acter1a are ~55 capa6~ 0f de9rad1n9 the c0mp0und5 0cc1uded/trapped 1n the p01ar matef1~ ad50r6ed 0nt0 0r a550dated w1th m1ner~ 5u~ face5 and the a~0~ated water f11m. Petr0~um f1~d 1ndu~0n extract5 are the ~a5t mature extract5 1n the 5amp1e5 ~0m the A9at F1dd. 7hey appear t0 6e m0re f1mHar t0 the 1a5t 5e4uenf1~ extract (E0M-3). 7h15 may 1mp1y that petr01eum f1u1d 1nduf10n5 d0m1nant1y capture petr0~um ~0m the 5~0n9e~ ad50r6ed 1ayer (here repre5ented 6y the h5t ex~ac0, 1.e. a m0re p01ar 61tumen. Hence petr01eum f1u1d 1nduf10n5 may 0r191nate ~0m a 5u65et 0f the 011 1n p1ace, 1.e. a 50~ 0f ~pre~act10nat10n~ m19ht have taken p1ace. Wherea5 the petr0~um f1u1d 1ndu~0n5 9eneraHy repre5ent d05ed 5y5~m~ 1t 15 f1ke~ that 0r191n~ d1fference5 6etween 5e4uent1a1 extract5 have 6een reduced 6y d1ffu510na1 pr0ce55e5 (c£ E n ~ a n d et a1., 1987). A11 5e4uent1~ extract5 0f the A9at F1dd 5amp1e5 5h0w f19n5 0f evap0rat1ve ffact10naf10n. 7h15 5u99e5~ ~ther that evap0rat1ve ~acf10naf10n t00k p1ace dur1n9 5ec0ndary m19rat10n, 0r m0re 11kdy that 9a5 ~act10naf10n ha5 6een capa6~ 0f ~f1pp1n9 pa~ 0f the C~5 t0 C25 n-a1kane5 0cc1uded/trapped 1n the p01ar c0mp0und5 ad50r6ed 0nt0 m1ner~ 5u~ face5; 1.e. p01ar c0mp0und5 d0 n0t trap na1kane5 a5 eff1c~nf1y a5 cyd1c m0~cu1e5 under 5u65urface c0nd1t10n5, at ~ a ~ 1n the 5amp1e5 ~ud~d. 7he data ~0m 5e4uent1~ ex~acf10n have t0 6e 1nte~ra~d w11h d e t ~ d 9e010~c~ 1nf0~ mat10n; 0therw15e they are 0f htf1e u5e. 5e4uent1a1 extract10n appear5 t0 6e 0f 11m1ted u5e 1n r0ut1ne a n a 1 y ~ h0weve~ 1t may hdp t0 501ve 5pe~f1c pr061em5, e.9. r d a ~ d t0 610de9radat10n and evap0rat1ve ~acf10naf10n.

1171

Ack~0w~d9em~--5a9a P~m~um A.5. 15 ~anked ~ r

p r 0 ~ n 9 5am~e m~ef1~ and f1nand~ 5upp0~ (A.W.L 8P N0rway 15 ackn0w~d9ed ~ r ~e U~ ~ d d ~m~e. We ~ank N19d Mff15~ r hdp~1 c0mmem5.

REFERENCE5

8ehar F. and Vanden6r0ucke M. (1988) Chara~er12af10n and 4uant1f1cat10n 0f 5aturate5 ~apped 1nf1de ker09en 1mp1~at10n5 f0r pyr0~5ate c0mp0f1110~ 0r9. 6e0chem 1~ 927-938. En~and W.A., Macken~e A.5., Mann D.M. and Q ~ e y 7.M. (1987) 7he m0~ement and entrapment 0f pe~ r0~um f1u1d51n the 5u65urface. 2 6e0L 50c. 144, 327347. 6hen1ma R. (1993) Etude de5 r0che5-mere5 pa~02~4ue5 du 6a~n de 6hedame5. M0dd~af10n de5 hydr0car6ure5 m19re5 et app11cat10n a 1~ude du ~5ement d~1 80rma. Ph.D. thef1~ U~verf1ty 0f 0dean5. H0r~ad, 1. and La~e~ 5.R. (1997) P~r0~um m19rat10n, (4) ~ r a t ~ n and re-m19rat10n w1th1n the 7r011 F1dd, N0rwe~an N0~h 5ea5. 8u~ Am. A550~ Pe~. 6e0L (1n pre~L Kad5en D. (1992) P~r0~um h~er0~en~t1e5 1n Ma5t1c re5erv01~. Dr. 5~ent. thef1~ Un1ver51ty0f 0~0. Ka~5en D. and La~er 5.R. (1991) An~yf15 0f petr0~um ~act10n5 6y 7LC-F1D: app11cat10n5 t0 petr01eum re5e~ v01r de5cr1pt10n. 0r9. 6e0chem. 1L 603-61~ Kad5en D.A., Nedk~tne 7., La~er ~R. and 8j~dykke K. (1993) Hydr0car60n c0mp051t10n 0f auth19en~ 1nduf10n~ App11cat10n t0 e1u~dat10n 0f p~r01eum re5e~ v01r ~11n9 h1~0ry. 6e0ch1m. C05m0ch1m. Acta 5~ 36413659. Lafa9ue E. and 8ehar F. (1989) App11cat10n0f a new preparat1ve pyr01y515 tectn14~e fcr t~e determ1nat10n 0f 50urce-r0ck type5 and 0~0urce-r0ck c0rre1at10n5. 6e0ch1m. C05m0ch1m. Acta 5~ 2973-2983. L0ve 6.D., 5nape C.E., Carr A.D. and Law 6. (1991) A 5e4uent1~ extract10n pr0cedure t0 hdp d1fferent1atephyf 1 c ~ ~apped and c0va1ent1y 60und ~kene5 1n 011 (5) 5h~e5. 1991 Ea5~rn 011 5h~e 5ymp0~um, N0v. 13-15, 1n5t1tu~ f0r M1n1n9and M~er~5 Re5earc~ Un1verf1ff 0f Kentucky. Nedk~tne 7., Kar15en D.A., 8j~ykke K. and La~er 5.R. (1993) Rdat10n5h1p 6~ween re5erv01r d1a9enet1c ev01ut10n and p ~ 0 ~ u m emp1acement 1n the U1a F1dd, N0~h 5ea. Ma~ Pe~0L 6e0L 1~ 255-27~ Pf1ce L.C. and C1ayt0n J.L. (1992) Extract10n 0f wh0~ ve~u5 9r0und 50urce r0ck5: fundament~ petr0~um 9e0c h e m ~ 1mp11cat10n5 1ndud1n9 0~ 50urce r0ck c0rre1at10n. 6e0ch1m. C05m0ch1m. A~a 5~ 1213 1222 5~90 C., Maxwe11 J.R. and Macken~e A.5. (1983) Ev~uat~n 0f ~acf10naf10n effe~5 dur1n9 the ea~y ~a9e5 0f pr1mary m~rat10n. 0r9. 6e0chem. 5, 65-73. 5p1r0 8. (1984) Effect5 0f the m1nera1matr1x 0n the d1~f1(6) 6ut10n 0f 9e0chem~ marker5 1n t h e r m ~ affected 5e~mentary 5e4uence5. 0r9. 6e0chem. ~ 543-559. 7h0mp50n K.F.M. (1991) C0ntra5t1n9 character15t1c5 (7) a~f16uted t0 m~rat10n 065erved 1n p~r0~um5 re5erv~red 1n c1a5t1c and car60nate 5e4uence5 1n the 6 ~ f 0f Mex~0 re~0n. 1n Petr0•um M~rat~n (Ed1~d 6y En~and W. A. and F1eet A. J.), pp. 191 205. 7he 6e010~c~ 5 0 ~ L0nd0n. WHhdm5 A. (1993) A5pe~5 0f the 0r9an~ 9e0chem~try 0f 1n 0rder t0 e v ~ u a ~ the 9enera1 app1~a6111ty 0f the the M1Her F1e~ re5u1t5 ~0m c0mparat1~e a 5 p h ~ r e c0nduf10n5 reached 1n th15 ~udy m0re 5amp1e5 pyr01y~5 and 5e4uent~1 extract10n. 1n5f1tut Fran4~5 du P ~ r ~ 1n~rn~ ~ep0~ n0. 41072. ~0m d1ver5e 9e010~c~ 5ett1n95 5h0u1d 6e exam1ned.

A. W1~dm5 ~ aL

1172

APPEND1X A

C0mp0und 1dent1f1cat10n ~ r F195 7 and 9. C0mp0und n~ 1

2 3 4 5 6 7 8 9 10 11 12 13-22 23 24 25 26 27 28

C0mp0und ~ent1f1cat10n C23 ~Cy~C ~ a n e C24 ~ y d ~ ~rpane C~ u~11c ~ a n e C24 ~t~cyd~ ~ a n e 18~ (H)-22,29,3~tr15n0rne0h0pane 17a (H~22,~,3~5n0~0pane 17~ (H),21f1 (H)-2~3~5n0rh0pane 17f1(H),21f1 (H)-3~n0~0pane 18a (H~3~n0rne0h0pane 15~ -m~hy1-17a (H)~%n0~0pane 17~ (H~ 21f1(H)~0pane 17f1(H~ 21~ (H~h0pane 17~ (H~ 21f1(H) 2 ~ and 2~R) ex~nded h0pane5 (C~-C3d 13f1 (H~ 17~ (H), 20(~-ch01e5tane 13f1(H~ 17~ (H), 20(R)-chde5tane 2 ~ e ~ - 5 a (H~ 14~ (H~ 17~ (H~ 20(~-chd~mne 2~e~ (H), 14f1(H~170 (H~ 2~R)~h0~ane 2~e~ (H), 14~ (H~17f1 (H~ 20(~-ch01e5tane 2 ~ h ~ - 5 ~ (H~ 14# (H~ 17# (H), 2~R)~h0~ane

A66~, C237 7E7 75

7m 8NH n0rh0p C2975 ~a h0p m0r

APPEND1X 8

Exp1anat10n 0f a 6 6 r e ~ n 5

u5ed ~ ~ e 5 :

E 0 M = e ~ r a c ~ e 0r9a~c m ~ 5at HC = 5~ura~d hydr0car60n5 5~%, ar0%, re5% = percen~9e 0f 5atura~d hydr0car60n~ ar0mat1c hydr0car60n5 and p ~ a r m~ef1~ 0f E 0 M n-a1kane5 = n-a1kane5 ~um 0f C15 t0 C30) C29 5terane5 = 5um 0f C ~ 5~rane5 C30 h0pane = 17~ (H)~1f1 (H)-h0pane P~Ph = pf1~ane/phymne; P~nC17 = pf1~an~heptadecane; P~nC18 = phymn~0c~decane n C 1 ~ C 1 7 + nC2~ = heptadecan~(hep~decane + hep~c05an~ C27% f1f120• C28% f1f120• C29% f1f1205 = 5terane car60n num6er d15tr16ut10n ca~u1ated u51n9 the 5~ (H~ 14f1(H), 17f1 (H~ 2~5) 150mer5 C27~a 5/(5 + R) = 13f1 (H), 17~ (H~ 20(5)-chCe5tane/(13~ (H), 17~ (H~ 20(5)~h0~5~ne + 13f1 (H), 17~ (H), 2~R)ch0~5~n~ 205/(205 + 20R) = 2~eth~-5~ (H), 14~ (H~ 17~ (H), 2 0 ( 5 ) ~ h 0 ~ 5 ~ n e ~ 2 ~ h ~ - 5 ~ (H), 14~ (H~ 17~ (H), 2~5)ch01e5tane + 2 ~ h y 1 - 5 ~ (H~ 14~ (H), 17~ (H), 20(R)~h01e5~n~ ~/(f1~ + ~ =24~th~-5~ (H), 14f1 (H~ 17f1 (H~ 2~R) and 20(5)~h0~aane/(2~hy1-5~ (H), 14f1(H~ 17f1(H), 2~R) • 2 ~ 5 ) ~ h d e ~ a n e + 2 ~ h ~ - 5 ~ (H), 14~ (H), 17~ (H~ 2~5) • 2 0 ( R ) ~ h 0 ~ a n ~ 225/(225 + 22R) = C~17~ (H), 21f1 (H)h0pane 2 2 ( 5 ) / ~ 5 ) + 2~R)) 7 E 7 / ( 7 E 7 + C237); m 0 ~ h 0 ~ 75/(75 + 7m~ C297~n0rh0p; ~ n 0 r h 0 p ; 8 N H / ~ 0 r h 0 p + h0p) 5ee Appen~x A ~ r c0mp0und ~ent1f1cat10n ~ u m n thre~