The URL can be used to link to this page

Home My WebLink AboutGMC Data Report No. 252 Kemik Sandstone - petrology, physical properties, and facies of outcrop samples and of subsurface samples from the following wells: Exxon Corp. Point Thompson Unit No.2 cuttings (13,060 - 13,140') and core ( 13, 124'), Exxon Corp. Point Thompson Unit No.3 core (13,742' - 13,904'), Home Oil Co. Bush Federal No.1 (11,150' - 11,220'), and Mobil Oil Corp. Echooka Unit No.1 core (12,797' - 12,874'). See article by Rocky R. Reifenstuhl in Short Notes on Alaska Geology 1995, State of Alaska Professional Report 117, page 53-67. Received 7 August 1995 Total of 16 pages in report Alaska Geologic Materials Center Data Report No. 252 ~ -. ~ I"" .. " .... - J ...... I --- li.emik Sandstone - petrology, physieal p.·opeI-ties~ and faeies of 40 oute.-op and subs...·faee SëUI1.ples. C;:tnn¡n~ Rive.- to Saga,ré4"..¡..-ktok Rive., northeast North Slope, Alaska :11' I' t¿'H~~~~~"'d~,*W"'¥M*WWà~~;';i;~':~ Alaska Department of Natural ~ Division of Geological and Geophysical Suneys For Bureau of Economic Geology University of Texas at Austin, Austin, Te:s:as For U.s. Minerals Management Service Continental Margins Program Year 9 Cooperative Agreement No. 14-35-0001-30643 January 1994 GMC Data Report No. 252 1/16 if ~ ~ 1 1 i i ~, t -- .,..~_...- Kemik Sandstone - petrology, physical properties, and facies of 40 outcrop and subsurface samples, Canning River to Sagavanirktok River, northeast North Slope, Alaska TABLE OF CONTENTS page ABSTRACT 3 INTRODUCTION 3 LOCATION AND DISTRIBUTION 5 PREVIOUS INVESTIGATIONS AND KEMIK SANDSTONE NOMENCLATURE 5 STRATIGRAPHY OF THE KEMIK SANDSTONE AND ADJACENT FORMATIONS 7 PALEONTOLOGY 8 MEASURED SECTIONS: LITHOFACIES, SEDIMENTARY STRUCTURES AND DEPOSITIONAL ENVIRONMENTS 12 Summary of sedimentary structures and depositional environments 17 PETROGRAPHY 1 9 Point counting 19 Provenance 1 9 PHYSICAL PROPERTIES 23 Porosity 23 Grain Density 23 Permeability 23 Thermal Alteration Index 23 Vitrinite Reflectance 26 RESERVOIR POTENTIAL 26 SUBSURFACE CORRELATION 26 SUMMARY AND CONCLUSIONS 27 ACKNOWLEDGMENTS 27 REFERENCES 28 LIST OF FIGURES 1. Location map of northeastern Alaska showing Kemik Sandstone isopachs and well locations 4 2. Generalized stratigraphic section for northeastern North Slope, Alaska 6 3 ° Generalized Kemik Sandstone measured stratigraphic section, depositional environment. and relative sea level curve. Canning River, northeast Alaska 13 4 ° Generalized Kemik Sandstone measured stratigraphic section Echooka River. northeast Alaska 14 5. Kemik Sandstone generalized depositional environment model 18 6. Quartz-Feldspar-Lithic triangular plot of petrography from Kemík Sandstone. and equivalent sands 20 70 Kemik Sandstone, and equivalent. graph of point count data from well samples 22 80 °Kemik Sandstone. and equivalent graph of chertlchert+lithics verses total chert 22 Kemlk S;:tndstone, northeast North Slope, AI <1 SK<J , Relfenstuhl. R R, AKDGGS. 12/93 USMMS Agreement # 14-35-000 1-3064 3 GMC Data Report No. 252 2/16 PETROGRAPHY Petrographic study of more than 100 thin sections of the Kemik Sandstone, and equivalent rocks indicates a predominantly very fine to fine--grained, with lesser medium and coarse-grained, moderately to well sorted, subangular to subrounded sublitharenite to litharenite (Folk classification). It is composed of 75 to 80 percent quartz. 15 to 20 percent rock fragments. and less than 5 percent feldspar (figure 6). The quartz is dominantly monocrystalline. with minor amounts of stretched metaquartz and vein quartz (table 2. Chert is the dominant rock fragment with lesser shale. siltstone, limestone, dolomite, and siliceous sandstone. Glauconite. muscovite, sericite. collophane, zircon, and tourmaline are minor constituents. Silica cementation is extensive as quartz overgrowths. Pebbly sandstone and conglomerate are locally important and clasts consist dominantly of quartz and gray to black chert. The Pt Thomson sand is dominantly dolomite-clast conglomerate. Point counting Detrital modal analyses were completed on a total of 36 Kemik thin sections; 17 were from drill holes. and 19 from surface exposures: POINT COUNT SAMPLE LOCALllY Mobil Echooka # 1 Bush Federal Pt. Thomson #2 Pt. Thomson #3 Outcrops: Canning River to Echooka River NUMBER OF THIN SECTIONS POINT COUNTED 4 7 3 3 18 In addition to point counting, more than 60 thin sections yield information on texture, mineralogy. alteration. and diagenetic history. Point count methodology for the predominantly very fine grained sandstone, was 300 points (on 24 stained thin sections) and 100 grain counts (on 12 stained sections). Table 2 summarizes point count data; appendix 1 lists detailed point count data. Thin sections were stained for calcite (alizarin red) and ankerite (potassium ferricyanìde), and some impregnated with blue epoxy resin. Compositional differences are shown on the triangular plot of Ouartz(+chert)-Uthics-Feldspar (figure 6), cumulative histogram of the same groups (figure 7). and a graph of Chert/Chert + Uthics versus Total Chert (figure B). Modal clast analyses indicate a progressive quartz decrease and lithic (predominantly chert and carbonate) increases from southwest to northeast: Bush Federal to Echooka to Pt Thomson (figure 7. Provenance Framework grains of the Kemik in the Canning and Echooka River area surface and subsurface suggest a mature sedimentary provenance with a minor metamorphic source contribution. Protoliths include Sadlerochit Group sandstone (permian to Triassic), Kekiktuk Conglomerate (Lower Mississippian). as well as other lower Paleozoic rocks which may have contributed quartz. lithics (including micaceous quartzite, and minor feldspar. Some chert clasts in the Kemik are similar to chert of the Lisburne Limestone Group (Mississippian to Pennsylvanian). G~ Bå~~oReP~~Ñ~~252Pe. AJ;;,sk¡). Reífenstuhl, R.R.. AKDGGS.12/93 USMMS Agreement # 14-35·0001-30643 19 3/16 QUARTZ-FELDSPAR-LITHIC· PLOT KEMIK SANDSTONE, AND EQUIVALENT SANDS LEGEND Quartzose Components . Echooka # 1 Number of samples 36 Num ber of overlapping points shown by offsest values Pt Thomson # 2 and o Pt Thomson #3 Qa=quartzarenite sa=sutJarkose sl=sutJlitharenite A Outcrop samples G 0 Bush Federal Q.) -6..J .~ c::. C1J Cl.) Cr) c... ~ C'C ~ (Ù ~ -..J ~ ~ c... . ,..., . """ ro c::. :f -.. ~ (..J u <:.- r§ ....., cO .c::: .""'" ~ ......... tf) ~ ....., a . """ ......, ~ .-' c... ro Feldspathic Components Lithic Components Figure 6. Ouartz-Feldspar-Uthic triangular plot of petrography from 36 Kemik Sandstone and equivalent sands. 'Quartzose components' include chert. Point counts per thin section are 100 or 300 (see table 2 and appendix 1 for petrographic details). Classification is from Folk (1969). GMC Data Report No. 252 4/16 C) ~ () t:1 ~ ~ Table 2. Kemik Sandstone. and equivalenl. point count data ~ ~ (Ð Sample Total pn 0Jerty- White Heavy Minerals: Detrital Mtx Mtx Silica "CartIonatc Clay ()Iher "0 0 number COIIIIt , Qm Qpe Qpf Kspar Plagioclase Chert Phyllite Arg Sandstone 0 Shale Carboøatc Glauconite Mica ZrTrRtGt Other Arg o Uncfiff Porosity PordiU PordiIl Pordin Porefdl ::4 f( () ... e.. BUSH 11150 100 47 18 2 19 ] 6 4 2 7 13 J Z '(},-/ BUSH 11160 100 50 25 16 I 3 4 I 1 8 ~ e~~ ?BUSH 11170 100 72 8 17 2 7 2 Fele.r.J. BUSH 11180 100 47 18 2 2 19 8 3 8 10 I tv I , BUSH 11190 100 57 18 :!2 I 1 LIt 8 tv " BUSH 11200 100 61 18 2 15 3 4 I " BUSH 11220 100 58 23 2 15 2 2 8 2 £"IIOn PtTh3-13904 100 3 5 92 4 [1<l<un PtTh3-13833 100 35 II 5 41 5 5 4 &11<"" PtTh3-13742 100 3 28 4 5 30 5 24 5 I 001),. PtTh2-I3060 100 38 15 2 1 16 18 2 10 2 6 13 4 ? &xCI'! PtTh2-13101 100 37 13 5 19 5 3 1 9 2 5 1 3 2 3 2 4 £¡v«()r PtTh2-13124 300 45 21 5 2 114 15 I 50 3 1 10 31 ( "",,¡,..¡ EdWo 12791 300 121 5 4 27 45 II 6 2 4 7 3 34 1 21 £c.hcøl... F..chka 12833 300 156 8 3 33 22 II 2 II 4 2 26 2 23 " Ec:bk.a 12874 300 115 4 2 J8 19 5 5 2 3 7 13 93 4 5 , I Echka 12860 300 104 9 1 44 43 13 7 1 1 2 10 15 28 I 12 7 I /3 i IP "'/~11ft'1 9IRR68A 300 160 6 I 26 I 1 2 6 5 I 44 31 1 15 ~ 9IRR68B 300 151 14 2 57 1 6 I 3 1 36 2 16 91 RR68C 300 95 S 20 2 3 4 4 2 31 20 2 20 9IRR68D 300 126 28 4 7 43 39 2 40 91RR11A 300 131 3 S3 19 6 1 8 3 58 1 2 1 91RR13A 300 115 6 36 2 1 1 2 2 9 117 1 9IRR13B 300 151 4 3 13 2 5 2 2 13 56 6 8 28 91RR16A 300 65 5 3 12 3 5 I I 110 I 1 91RR16B 300 165 8 23 2 30 69 I 91RR76C 300 62 11 2 10 I 16 14 1 5 145 3 I 91RR18A 300 127 1 1 47 8 4 5 1 9 S9 6 20 91RRSOA 300 125 II 42 21 6 2 2 5 7 66 10 3 91RR81B 300 46 3 14 1 I 21 12 I 12 91RR81C 300 91 5 22 I 6 3 4 4 3 141 5 14 91 RR84-00 300 118 12 30 3 10 5 5 2 7 3 88 6 9 1RR84-1 9 300 116 1 2 42 31 9 2 3 3 2 8 31 2 23 17 91RR86A 300 105 9 3 36 28 7 4 ]0 3 5 9 10 4 57 6 91RR92 300 JlO 6 30 4 I I I 11 134 1 91RR9OC 300 144 4 2 12 8 5 15 53 12 18 24 Qm = MODOayStIIlIioc Q.tz; Qpe = PoIyaystaIliDe Quanz - equigmnular. Qpf = PoIyaystal1ine Quartz - foüaIed.; Kspz:: AIbIi Fddsiw; Ckny-AIg =Qeny ArgiIli1e;SandsIooe ÏDt:Iude5 mic:accous qmnziIc; Heavy MiDcRIs: ZrTIRtGt = Zircoo. TourmaliDe. RuåIe.. GImct; DetritaJ 0Ibcr iDcJudes nae bioIite (6 counts in 91 RR1 IA) and granitic: clast (I in 91RR16c); Mtx AI¡ = ArgiIbceousIPse MIX UIIdiff = Mattix UodiffeRDtiascd; Silica PorftD iødudes quartZ ~ Ûlbooa1I: Pon:f"aD ÌII/::IDdieS siderite; Cay PorefiD iøcludes glauconitic clay; Other PtxdiII includes deadoiL BUSH=: BasIl Federal '1. and five digit number is well dcptb.in feet; PtTh3 = Pt 1homsoa ff3; EdJka = Echoob '1; 91RR.- - =outcn1p samples_ LIt - ~ 0'\ KEMIK SANDSTONE AND EQUIVALENT POINT COUNT DATA FROM WELL SAMPLES . Uthlcs+chr (100 to 300 points per thin section) m Feldspar [3 Quartz 100% 90% 80% 70% 60% % 50% 40% 30% 20% 10% 0% IIIIIII =~i!:~i~i!'¡"¡t"',',1'i:!¡i" ~ !!,¡i.:i~!i,!l ','j'~:~:":¡1 - :{)!:"?i ' ,:' '·:{i!; -ii,::i'!:i¡'¡;' '1;~o;¡':,I:: :: !::¡):iJ¡, -'I "'1'1" ':;1':,':1,1' :'1 "','I,,I¡IIII :1,1;',,1,1"'1::' "I I I :,'¡I!I. ..!:II',I:,'III'I:I·I' _~,¡;;li:l!iIJi:: ,I :~::, ,,' I .11!;i':I'I:¡,'lil:,:!' !¡·I,I'II:I,:I::I:!':: ,¡'¡;:¡:¡:¡:II'I!: . :,'1 ". I '1,,1. ',',. I ,'.' "J I':', ~ I l;~1:'¡i ~~:i. .,!lilII,!·. 11'I'f·"1 ;;'i,:",: ::1/'':;;.::, I':I:'I',!"'; ,:IIII'IIIII!:"I" ),!i£::'I;;:¡' il:¡'I: ¡~;'!:: , ; j ,.¡::,'" I i ¡,. \!lfl,...¡ .\1111' I!I' '.:' i ·~II ¡r" 4 B. B· B· B· B· B· B· PT3· PT3· PT2· PT2· PT3- PT2. Echk Echk Echk Echk 1115 1116 1117 1118 1119 1120 1122 1390 1383 1306 1310 1374 1312 1279 1283 1287 1286 o 0 000 0 0 4 3 0 1 247 3 4 0 Point Count Sample Figure 7. Kemik Sandstone, and equivalent, graph of point count data from well samples. Data ·show significant increase in lithic clasts (chert and carbonate) from west to northeast (Bush Federal-to Echooka- to Pt Thomson well. B = Bush Federal; PT = Pt Thomson; Echk = Echooka. Five digit number is sample depth (in feet) in well. See table 2 and appendix 1 for point count data, and plate 1 for locations. Pt Thomson #2 Pt Thomson #3 Bush Echooka . ... + . 0.9 - + \ 0.8 - en 0.7 - + (J + s: 0.6 - I- :i + ¡:!: 0.5 - et: . UJ :1: 0.4 - (J . . . ¡:: a:: 0.3 - UJ . . :1: (J 0.2 - 0.1 - ~ Â .Â. . 0 1 I I I I I 0 10 20 30 40 50 GO 70 80 90 TOT AL QUARTZ (%) Figure 8. Kemik Sandstone. and equivalent, graph of ChertlChert+Uthics verses Quartz; point count data from well samples. Data show significant increase in lithic clasts (chert and carbonate) from west to northeast (Bush Federal-to Echooka- to Pt Thomson well. See table 2 and appendix 1 for point count data. and plate 1 for locations. GMC Data Report No. 252 6/16 One granitic clast was counted in an outcrop sample (91 RR76A) and one locality included biotite. Pt Thomson well samples are predominantly conglomerate comprising dolomite clasts, apparently from the underlying Katakturuk Dolomite (Precambrian). Local sources for the Kemik are indicated by significant differences in framework grain abundance (figures 6, 7 and 8), as seen in the increase of chert and carbonate, from southwest to northeast, in the progression from Bush to Echooka to Pt Thomson wells. PHYS ICAL PROPERTIES More than 60 samples were analyzed for porosity, permeability, grain density, or Thermal AJteration Index (TAJ). Forty-eight of these surface and subsurface samples were analyzed for porosity, permeability, and grain density (table 3; appendix 2). Additional subsurface physical data were compiled from published well reports (table 4). Vitrinite reflectance data was part of micropaleontologic analyses (table 1 ; appendix 3). Porosity Porosity values for all samples range from 0.8 to 14.1 percent and average 5.3 percent. The maximum porosity of 14.1 is an outcrop sample of pebbly sandstone just above the LCU. Subsurface samples range from 3.9 in the Echooka well to 8.4 in the Pt Thomson #2 well, and average 6.2 percent. Comparing the average porosity of the 43 surface samples (5.3) to the average porosity of the 5 subsurface samples (6.2) shows a 17 percent higher subsurface porosity Grain Density Grain density values (in grams/cm3) range from 2.57 to 3.05 and cluster in tNo populations, the principal cluster (74 percent of the total population) at 2.64 and a smaller cluster (26 percent) at 2.90 grams/cm3 (appendix 2). There is no apparent correlation betvv'een grain density values and porosity (figure 1 of appendix 2). Six samples yield grain density values 1 0 percent greater than the average for the cluster of 17 samples. AJI 6 of these high-density samples are outcrop samples of medium-grained sandstone to pebble conglomerate from within one meter of the basal Kemik (LCU). These coarse-grained clastic rocks represent lag-type deposits, which, presumably, have been substantially reworked and sorted during sea levellowstands. Permeability Permeability was reported on 17 Kemik rock samples as Routine Air Permeability in millidarcys (md) and Insitu Klinkenberg Permeability (md; appendix 2). Insitu Klinkenberg Permeability Values range from 0.00012 md to 0.0157. One anomalously fractured sample yielded 0.271 md, and is not considered representative. Permeability and porosity values are the result of burial and thermal histories. Decreasing maximum burial and thermal exposures result in higher permeability and porosity values. Four subsurface permeability samples from the Echooka well range from 0.00253 to 0.00020 md. Thermal Alteration Index Thermal Alteration Index (TAJ) values for 11 Kingak Shale samples range from 2.5 to 3.8 (average 3.4). One Pebble shale analysis is 3.0. One outcrop sample from the Kemik Sandstone is 2.7(7). Outcrop sample TAJ values are listed with micropaleontology analysis in table 1. Kemik correlative sands from the Aurora well yield 3.2,3.8, I GMC Data Report No. 252 7/16 I Kemìk Sandstone, northeast North Slope, Alaska, Reifenstuhl, R.R., AKDGGS. 12/93 USMMS Agreement # 14-35-0001-30643 23 Table 3. Kemik Sandstone porosity, permeability, and density data Ambient Ambient In-situ Klinkenberg Grain Sample Sample Porosity (%) Air K (md) Permeability (md) Density œ!cc) Type 91 RR68A 2.5; 3.0 0.0063; - - 0.00037, - - 2.66; 2.66 P; T.S. 91 RR68B 6.6; 6.5 0.0284; - - 0.00495; - - 2.63; 2.62 P; T.S. 91 RR68C 7.8 2.67 T.S. 91 RR68D 5.9; 4.0 0.0395; - - 0.00236; - - 2.62; 2.63 P.; T.S 91 RR71A 4.7; 4.8 0.0061; -- 0.00064; - - 2.64; 2.64 P; T.S. 91 RR 73A 1.8 2.64 T.S. 91 RR73B 0.8; 1.7 0.0326; - - 0.00024; - - 2.63; 2.64 P; T.S. 91 RR 76A 6.7; 14.1; 1.7 0.0189; 0.0309; - - 0.00018; 0.00283; - - 3.05; 2.93; 2.64 P; P; T.S. 91 RR76B 7.3 2.64 T.S. 91 RR76C 5.7 2.95 T.S. 91 RR78A 6.3; 6.9 0.0782; - - 0.0081; -- 2.63; 2.63 P; T.S. 91 RR80A 5.6; 8.3 0.0311; - - 0.00294; - - 2.65; 2.65 P; T.S. 91 RR80B 3.6 0.0794 0.00227 2.93 P 91 RR81B . 6.7 2.62 T.S. 91 RR81C 6.4; 6.5 0.0057; 1.61* 0.00107; 0.271* 3.01; 3.02 P;P 91 RR84-oo 3.9 2.66 T.S. 91 RR84-19 3.4 0.127 0.00375 2.64 P 91 RR86A 2.3; 3.3 0.0069; - - 0.0005; -- 2.67; 2.69 P; T.S. 91 RR90C 7.3; 6.7 0.0574; - - 0.0157; - - 2.64; 2.62 P; T.S 91 RR92D 3.3; 3.9 0.0344; 0.0069 0.00051; 0.00012 2.78; 2.79 P;P 84 AMu113-6 4.2 0.0146 0.0015 2.65 T.S. 80 AM u3-4 2.7; 2.1 0.0427; 0.0141 0.0012; 0.0005 2.66; 2.66 T.S.; T.S 80 AMu13-5 6.4 2.66 T.S. 80 AMul4-1A 3.9 0.0068 0.0003 2.79 T.S. 80 AMul4-8 5.8 0.0356 0.0021 2.66 T.S. 80 AMul4-10C 6.3 2.75 T.S. 80 AMu15-3 9.4 2.57 T.S. 80 AMu19-2 8.1 2.65 T.S. 80 AMu27-6 10.7 2.72 T.S. 76 AMu11-3 10.7; 8.7; 7.2 0.033; 0.437; - - 0.0052; 0.0971; - - 2.68; 2.65; 2.64 T.S.; T.S; T.S 76 AMu12-5 3.4 0.064 0.0046 2.66 T.S. 76 AMu15 7.0 2.66 T.S. 76 AMu30 1.1 2.72 T.S. 76 AMu31-2 6.1 0.0377 0.0028 2.65 T.S. 76 AMu32A 7.2 0.048 0.0082 2.66 T.S. 76 AMu32B 7.2 2.84 T.S. 76 AMu33 2.3; 4.3 0.0166; - - 0.00071; - - 2.66; 2.66 T.S.; T.S. 76 AMu69 3.3 0.0192 0.0007 2.64 T.S. 76 AMu72 3.3 0.0257 0.0016 2.65 T.S. 76 AMu108 3.0 0.00905 0.00022 2.73 T.S. 76 AMu116 8.4 0.0245 0.0028 2.64 T.S. 76 AMu117 11.0 0.0157 0.0012 2.65 T.S. 76-78 AMu12-5 2.9 2.63 T.S. Echka-12797 6.3 0.0098 0.00123 2.64 P Echka-12833 7.4 0.0079 0.00084 2.65 P Echka-12860 4.8 0.003 0.0002 2.70 P Echka-12874 3.9 0.0701 0.00253 2.66 P PtTh2-13124 8.4 2.92 T.S. Analyses by A.P. Byrnes, Geocore T.S. = Thin section P = Core plug (0.34 inch or 1.00 inch diameter) *One split of sample 91 RR81C highly fractured, yielding anomalous values. Multiple analyses listed on one line, with corresponding sample type listed. GMC Data Report No. 252 8/16 3.4, and 3.6 (Banet, 1992; table 4). Vitrinite Reflectance Vitrinite reflectance values are from subsurface samples and range from the low of 0.6, in Pt Thomson #2 well, to 1 .25 and 1.20 in the Bush well, to 1 .6 in Nora, and 1.4, 1.6 and 1.8 in Aurora. The TAl and vitrinite reflectance values for Kemik and equivalent rocks indicate a wide range, as related to the zones of petroleum generation and destruction. In the Pt Thomson #2 well, values are below the peak oil generation window. The Bush well lies within the lower oil generation window. The Nora and Aurora wells lie just below the oil window and within the wet gas generation window. RESERVOIR POTENTIAL Kemik framework grains consists dominantly of stable grains of quartz and chert with little matrix, characteristics of a potential reservoir for hydrocarbons, However, silica cementation is common in outcrop samples. Although the permeability analyses of the outcrop samples do not suggest reservoir potential, surface Kemik values may not be representative of subsurface Kemik. Jamison and others (1980) report that the Put River Sandstone in the Prudhoe Bay field, which is approximately correlative with the Kemik, has porosity values averaging 1 2 percent and measured permeability of from 10 to 404 millidarcys. In addition, the Kuparuk River Formation, the upper part of which is probably correlative with the Kemik, is oil productive in the Kuparuk River oil field (Masters,on and Paris, 1987). SUBSURFACE CORRELATION The Kemik Sandstone correlates with several sandstone bodies that overlie the regional mid-Neocomian unconformity in the subsurface of northern Alaska: Put River Sandstone (Prudhoe Bay; Jamison and others, 1980), Cape Halkett sandstone (informal name; in NPRA), upper Kuparuk River Formation (Masterson and Paris, 1987). Point Thomson sand (sandstone and conglomerate, Point Thomson subsurface west of ANWR), and Tapkaruak sandstone and conglomerate (Aurora-# 1 well, Kaktovik area). Although all five of these sandstone units and the Kemik occupy the same stratigraphic position above the unconformity, all appear to be isolated bodies separated by areas of nondeposition in which the pebble shale unit rests directly on the unconformity (Mull, 1987.). However, a possible alternative correlation (Mull, 1987) is suggested by the reported early Hauterivian age of the SimbJrskites sp. from the Echooka River Kemik Sandstone section. In the Mackenzie Delta area, the unconformity at the base of the Mount Goodenough Formation is underlain locally by a shale section and by the Kamik Formation of middle to late Valanginian to middle Hauterivian age (Dixon, 1982). (The Kamik Formation is also known informally as the Parsons Sandstone, a gas productive interval.) The Kemik on the Echooka River is thus apparently coeval with the upper part of the Kamik Formation of the Mackenzie Delta area. The upper Kamik consists of barrier island deposits including: offshore, shoreface, tidal channel, and lagoonal deposition (Dixon, 1982). This Kamik Formation- Kemi k Sandstone correlation is plausible only if the base of the pebble shale unit rather than the base of the Kemik represents the mid-Neocomian unconformity (Mull. 1987). GMC Data Report No. 252 9/16 Kemik Sandstone. northeast North Slope. AJê!si«J. Reifenstuhl, R.R.. AKDGGS. 12/93 USMMS Agreement # 14-3S~OO 1 -30643 26 C) ~ n ö ~ ...... ~ :;;d ~ o ;:\. Z o tv Ut tv Table 4. KemiJ: Sandstone, and equivaltmt, subsurface daJa Thia RdÌOIIS {ample ÏDta"nII (1IIIÌÌ:aber of sampla)J Core DitdI 4,400' ~ 16.0S0' (89) T-.-.n- Muimam· C .(54 470 Porosity S aDd ~(md) ICcmik or equMJeat -.-. 3.583' - 3.780' 4,445" - 4,65O"(rq¡cat) TOCSa 1.51 o.s - 2ad 1.04 Well a ()penI&or KemiIt .Ic BP (0) Kavù: .Ic 3.463" - 3.490' LO - 4.0 (0) (0) ~ ARCO Fin ûatc.d 10.375' - 10.535' 2.17 (0) 4.ISO- 15.()2O' . 463 McCulloct I-zd (22) 1.37 Suzie III 12.990' - 13.080' (O) 13.020" - 13.060" AtIanIic (I) RicbfJdd Ec:boob c.cJ 12.736' -12.925" 2.04 12.781' - (0) 434 6.3/0.001238 Mobil ()j) 12.875" (10) 7.4/0.00084 1.79 4.8/0.00020 3.9JOJJ0253 Nora ñdcnI.1 12.460' - 12.560' 2.23 (0) 12.460' - 12.550" 468 Adaruic (7) Richfield Bush ~ 11.147' - 11.210' 3.13 at (0) ] 1.150' - 1 1.350' 455 Home Oil 11.150' (10) PL 1'bompsœ nc. I 13.013· - 13.116' 0.tJ7 - 7.0 10.750' - 13.«íO' - 13.140" 8.4/----aI Exxoa 'Ihamp5oD ~ 0.6 - 2.3 13.]ST(5O) (2) 13,124.g 12.837 - 12.995"(10) PI.. ~,g: 13.056' - 13.931· 0.5 - 5.0 13.159' - (0) 5-2.5$ rypically a1 Exxoa Tbompsog saød 1.0-7.0 14,()O8'(49) bigh cød 13.673' . 11.788"(8) Aaron '1 16.-443' - 16.620" 1.0 -20; (0) 14.680' -16.630' ¡ 472.. 16.400' ocs-y~ "T1pburú. saM" S.o. 15.750" (14) aroc: Total CIIpIIÍC carboa ~ '"' quartz: ~ ", ¡1 iii- 8:. poIyaysWIine; F'" (ddspar; L.. Iidùc clasts + chen cAmsInIl.o& ÞaiWJIe . DGGS d¡J-. 1993 0Jbiø~ (Pan::IpbysicaI-.Iyses of Kemit SaDdsIoDc core from d.Iis stady_ 'AnaIyses: GcoDare. A. Byrnes. 1993 bsaet. 1992 ~owauødocbeø. 1992 - o - - 0\ Vitriaite Rdkctau« (Ro) 1.6 (estiJnaU!d) GMC report 25 1.25 (cstinured) GMC report 168 1.20 GMC report 25 0.6 at 11.500' 0.5 at 8,000" 0.4 aI. 3,500' 1.411116.500' 1.6 arl6.7OO' L8 at 16.800" ~ CIasIs: Q:F:L b 2..648 2.65 270 2.66 2.92& 55:1:44 at 13,060' : 55:1:44 51:5:44 238 32"0:6811113.742" 47:0:53 at 13.833" 3:0:97 at 13.904· 47:0-.53 alI3.833· 321):68 at 13.74T 85:5:10 COIIImeuts Modeme inIt:rgraDuIar poru &. over-growths: minor ~ mic:roporous chen and pbosphaIe Pyrolysis: maure: G.P:I.OOO-3.000: P .1.=0.1-0.3; H1.=50-400: Ol.=<4O()'i Maturi~; GP .=<4,000; P .1.=0.2-0.9 , 51=0.26; 52=O.2!1; 53=0.81: Ma1urity: mupna1 ~y lerogaL GP.=I.(JOO-IO,OOO; P.L=O.I -0.3; H1.=<IOO: 01.=100-200 MOOerau: qWll1Z. chJoriIe. illite Minor pIagiodase. dolomite. pyrite. 51=0.38; 52=0..64; S3=0..69;(at 12.787-12.875") CoaJy~ · oil: 27'1> Sanzntes; SI.,(J.35 26$ AromaI.ics; 52-=0.25 47$ PoIars: S3=(1-74 51=0.75: 52=0.99; 53=1.33; Woody Jœrogeo Seven tIùø seaioas point COUDtecI. tbis study. IntergranuIar porosity dc:srroyed; Mica /k. sdñst paiD ØefurmaIioo · 248 bmdsIday. 21° API. 11.750" Tbree tbin~ poÍIIt 0J0DU>d. this study. · PyroIosis: ~ GP. çprox.. 1.000: P 1.=0.1-0.4; 1il=30-300 MiDor gas show. 18.200'; amorpõous lerogeJI MíDor gI.aøI:oaiIr!. TAl.. 3.2. 3.8. 3.4. 3-6. Kmûk-Kalubit-ICøpwK equivaJeDI PyroJisis: G.P.~ P .1.=0.1-0.3: H.L=50: O.L=<:SO PENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUTY, POROSllY AND DENSITY DATA GeoCore I l Subject Twenty five sandstone samples of Kemik Sandstone, primarity from outcrops on the North Slope Alaska, were submitted for porosity, permeability, and grain density anatysis. All porosity, permeability, and grain density data are presented in Table 1. Experimental Methods Sample Preparation Core plugs measuring either approximatety 0.75 or 1.00 inches in diameter and one to two inches in length were obtained from outcrop samples using a diamond core drill bit with tap water as bit coolant. The end faces of the core plugs were cut using a· diamond saw with tap water as a coolant. The samples were dried in a vacuum oven at 70 °C to a constant weight within + 0.003 gm. The samples were not humidity oven dried since porosities measured in this fashion do not reflect log measured porosities and are also not suitable for correlation with electrical resistivity measurements. Subsequent to porosity determination the radial surface of samples with a diameter of 0.75 inches were sealed in epoxy to provide an outer diameter of one inch for placement in the high pressure permeameter. Porosity and Grain Density Ambient Helium porosity was determined using a Boyle's Law technique. Dry sample weights were measured to +0.001 gm and bulk volume was determined to an accuracy of +0.01 cc by mercury immersion. Ambient Helium porosity was measured to an accuracy and precision of better than + 0.1 porosity percent. Grain density values are accurate to within + 0.01 g/cc. Porosity values averaged 5.3+2.5% while grain density values occurred in two clusters, a principal cluster (74% of the total population) at 2.64+0.02 and lesser cluster (26%) at 2.90+0.11 g/cc. It is not known what cementing agent is responsible for, the higher grain densities. Figure 1 illustrates both the general distribution of porosity and grain density and shows that there is no correlation between increased or decreased porosity with increased grain density. Ambient and Insitu Klinkenberg Permeability To measure routine air permeabilities and insitu Klinkenberg gas permeabilities, each core was placed in a Hassler type confining pressure cell and subjected to hydrostatic confining stresses to simulate insitu stresses. Confining pressures used were 300 psi and 3000 psi. Routine permeabilities was measured in order to provide a correction correlation for older routine data to insitu Klinkenberg values. A confining stress of 300 psi approximates the stress used by many routine laboratories especialty during the time of core anatysis for many earlier Alaskan wells. A confining stress of 3000 psi approximates insitu stresses at 6000 ft which is the very minimum depth of burial that these samples saw before overburden removal and the probable minimum depth of a prospective producing reservoir. Also a 3000 psi confining stress insures the closure of microfractures and represents conditions under which additional confining stress does not resutt in significant further permeability reduction. Ambient air permeabilities were measured at 100 psi differential pressure across the core. Klinkenberg permeabilities, which correspGnd to nonreactive liquid permeabilities or high pressure gas permeabilities were determined by GMC Data Report No. 252 11/16 Special Core Analysis Formation Evaluation Basin Analysis 187 Leanne Drive Loveland. Colorado 80537 (303) 667·5983 56 I 1<" '" - PENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUTY, POROSITY AND DENSITY DATA GeoCore pressure pulse decay. Ambient and insitu permeability data are presented in Table 1 and Figure 2. Permeability values were not obtained on thin section samples although porosity and grain density data were measured. The sample population was limited and represents only the lower porosity and permeability range of the Kemik Sandstone. However, based upon linear regression of the data measured here, a general correlation for conversion of lower value routine permeability data to lIinsitu" Klinkenberg values is: K. . =10(O.84.:0.21*1og1oK'rom.c+1.S2) tnsttu The standard error of prediction for this relationship is·a factor of 2.8 (e.g. a predicted permeability of 1 md might be 2.8 md or 0.36 md, 1 std. dev.) The effect of both confining stress and KJinkenberg correction decreases with increasing permeability, and by values approaching 1 to 10 md lIinsitull values are generally greater than 50% of routine compared with the 1-10% values exhibited by these samples. This amount of decrease from routine air permeability values to insitu Klinkenberg values is typical of many low permeability sandstones. Insitu Klinkenberg Permeability vs Porosity Again, given the limitations that the data presented here represent only the lower porosity and permeability values for the Kemik Sandstone, a correlation between porosity and permeability which might be useful in the range is: K. . =1 O(0.20.10.05*~,.,.,.-3.70) uasuu The standard error of prediction of this equation is a factor of 2.3. This equation was obtained by excluding the lowest three permeability samples and the two highest porosity"samples which are compromised either by fracturing or are not considered representative of the Kemik Sandstone. It is important to note that the porosity and permeability values here are largely the result of specific burial and thermal histories for the specific locations sampled. With decreasing maximum burial depth and thermal exposure porosity and permeability values increase. The oør.ions. raorpret8tions. an:! ana"". .hewn Í1 this Alport ¡w based upon observations and materialsupplied by the erert or in the p~rc domaÍ1. Alan P. ByrT1el. GeoCore, and b emp byee5 furnish to the best ct thei' ab iIty, ac:curate and comp lete data that were obtaned and comp j¡ed Í1 a prdesa ional manner. Howewr, bec:aule ct the Í'IhIM8rt Mac:tneu d geolog i:: i'lformáion and the Nbilty ct 8l'Pf penso" to know prøçise¥ the natlR d s~aurface formations or how to reproduce ,Ib,urfaee condti0r8 in the laboratory, Alan P. Byme6, GeoCore, and b empbyoes are unable to pl'OYi:Se 8l'Pf warram¡ . to the açcuracy orccxnplltene.. of the anattti:: proçedur'e15 employed Í1 the data coikÞc:tion or ct 8l'Pf and aD i'terpretations. nerencel, and conc:iaions dor;..ed from the data and ~ned in ths "'Port. Furthermore. they _s~ no r85po,.biay and make no warrart:y or repr85ertations 85 to attf decisiots, fi1ancial orotherwso, Í1 connection wth whi::h an¡ part cI this report. LSed or relied upon. GMC Data Report No. 252 12/16 Special Core Analysis Formation Evaluation Basin Analysis 187 Leanne Drive Loveland, Colorado 80537 (303) 667-5983 57 'PENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUTY, POROSITY AND DENSITY DATA GeoCore Table 1 Summary of Core Analysis Kemik Sandstone Samples Alaska Div. Geological & Geophysical Surveys Location J.D. Ambient Routine Insitu Helium Air Klinkenberg Grain Porosity Permeability Permeability Density (%) (md) (md) (glcc) 91 RR..sBA 2.5 91 RR-6SA 3.0 91 RR-6SB, 6.6 "., .,', 91 RR-688 " 6.5 91 RR..sSC !)A 7.8 91 RR-68D (I:-'ç":,:\ 5.9 91RR-68D· 4.0 91 RR-71A~' -- 4.7. 91 RR-71 A - 1\\\1\ 4.8 91 RR-73A - ; I//~ 1.8 91RR-738 - ~ 0.8 91 RR-73S- .: 1.7 91 RR-76Ä 6.7 91 RR-75A 14.1 91 RR-76A ,~\., 1.7 91 RR-768 .':,:, . 7.3 91 RR-76C 5.7 91 RR-78A - ~,ì~' 6.3 91 RR-78A or,'; 6.9 . I 91 RR-80A: H "" \t 5.6 91 RR-80A - ~,,\l\ 8.3 91 RR-SOB" 3.6 91 RR-81 8 5.7 91 RR-81 C 1:- ? 6.4 91 RR-81 C 6.5 91RR-84-06"" ¡'1\1\'~-~ 3.9 91RR-84-19J t~~3.4 '1 " 91 RR-86A \ tc\-.,¡;t:,\¡;" 2.3 91 RR-86A ) ~r 3.3 91 RR-90C ] \VI~"- 7.3· 91 RR-90C t - ~ 6.7_ 91 RR-92Dl9h 1. 3.3 91 RR-92D J ~~ 3.9 Echka-12797 6.3 Echka-12833 7.4 Echka-12860 4.8 Echka-12874 3.9 PtTh2-13124 8.4 0.0063 0.0284 0.0395 0.0061 I 0.0326 0.0189 0.0309 0.0782 0.0311 0.0794 0.0057 1.61F 0.127 0.0069 0.0574 0.0344 0.0069 0.0098 0.0079 0.0030 0.0701 0.00037 0.00495 0.00236 0.00064 0.00024 0.00018 0.00283 0.0081 0.00294 0.00227 0.00107 0.271 F 0.00375 0.00050 0.0157 0.00051 0.00012 0.00123 0.00084 0.00020 0.00253 2.66 2.66 2.63 2.62 2.67 2.62 2.63 2.64 2.64 2.64 2.63 2.64 3.05 2.93 2.64 2.64 2.95 2.63 2.63 2.65 2.65 2.93 2.62 3.01 3.02 2.66 2.64 2.67 2.69 2.64 2.62 2.78 2.79 2.64 2.65 2.70 2.66 2.92 Sample Type P TS P TS TS p TS P " TS TS P TS P p TS TS TS p TS P TS P TS P P T5 p p T5 p. TS P p p P P P T5 F - Fractured sample P - Plug (0.34 or 1.00 ~iam.) T5 - Thin section sample, no permeability Note: Routine confining stress = 300 psi, Insitu = 3000 psi GMC Data Report No. 252 Special Core Analysis Formation Evaluation Basin Analysis 13/16 58 187 Leanne Drive Loveland, Colorado 80537 (303) 667-5983 , ,I" \ I - ~: 'PENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUTY, POROSITY AND DENSllY DATA :~ GeoCore Figure 1 Porosity vs Grain Density Kemik Sandstone Samples 16 14 .. ~ ~ ~ >- 12 ... .- 0 0 10 '- 0 Q. E 8 ). . ::s .- - Q) ~ .. :J: 6--. . . ... C I . Q) .- 4 . .c - . . E . . . . <C .. 2 . . 0 2.60 2.65 2.70 2.75 2.80 2.85 2.90 2.95 3.00 3.05 Grain Density (glee) GMC Data Report No. 252 14/16 pecial Core Ana.lysis ormation Evaluation Basin Analysis 187 Leanne Drive Loveland, Colorado 80537 (303) 667-5983 59 PENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUlY, POROSITY AND DENSllY DATA GeoCore Figure 2 . Insitu vs Routine Air Permeability Kemik Sandstone Samples 0.1 0.01 /' I I ~ -c E ~ ~ .... -- - -- .Q ca m I E . I ~ / ~ /11 i / '2/ 52 / ~ I ~ .5 0.0001/ , · 0.0001 0.001 0.01 0.1 Routine Air Permeability (md) . -- 0.001 ¡A . . . K ::1 O(O.84.:0.21·1og1oK~+1.52) insìtu GMC Data Report No. 252 15/16 ~pecial Core Analysis ·ormation Evaluation Basin Analysis 187 Leanne Drive Loveland, Colorado 80537 (303) 667-5983 h() PPENDIX 2 KEMIK SANDSTONE: DETAILED PERMEABIUTY, POROSITY AND DENSITY DATA GeoCore Figure 3 IIlnsitu" Permeability vs Porosity Kemik Sandstone Samples 0.1 ~ " E ~ >- ..... .- - .- .c as ~ 0.01 '- (1) c. C) '- CL) .c c JJ 0.001 c .- 2 - - ::J ..... .- o c - - - 0.0001 o . . . 2 4 6 8 Helium Porosity (%) 10 _ (O.20zO.OS. ~ 7'C*tÏIIC -3.70) KiAd!u - 1 0 GMC Data Report No. 252 Special Core Analysis Formation Evaluation Basin Analysis 16/16 187 Leanne Drive Loveland. Colorado 80537 (303) 667-5983 61