UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY CORE POROSITY, PERMEABILITY, AND VITRINITE REFLECTANCE DATA FROM THE LOWER CRETACEOUS J SANDSTONE IN 141 DENVER BASIN COREHOLES 1 DEBRA K. HIGLEY OPEN-FILE REPORT 88-527 THIS REPORT IS PRELIMINARY AND HAS NOT BEEN EDITED FOR CONFORMITY TO U.S.G.S. EDITORIAL STANDARDS OR STRATIGRAPHIC NOMENCLATURE. ALTHOUGH THIS DATA HAS BEEN EXTENSIVELY TESTED, THE GEOLOGICAL SURVEY CANNOT GUARANTEE THAT IT WILL GIVE ACCURATE RESULTS FOR ALL APPLICATIONS NOR THAT IT WILL WORK ON ALL COMPUTER SYSTEMS. 1 USGS, DENVER, CO 80226 1988 ______________________________________________________________________________ INTRODUCTION THIS DATA RELEASE CONTAINS 143 DATA FILES IN IBM PC COMPATIBLE FORMAT; THIS INCLUDES A STATISTICAL CONDENSATION FILE AND INDIVIDUAL DATA FILES OF J SANDSTONE CORE POROSITY AND PERMEABILITY FOR 141 WIDELY DISTRIBUTED COREHOLES IN THE DENVER BASIN OF COLORADO AND WYOMING. THESE DATA HAVE BEEN USED TO RESEARCH THE RELATIONSHIPS AMONG SANDSTONE POROSITY AND PERMEABILITY, AND THE DEGREE OF THERMAL MATURATION OF THE J SANDSTONE OF THE LOWER CRETACEOUS DAKOTA GROUP AND ASSOCIATED HYDROCARBON SOURCE ROCKS. PUBLISHED MAPS AND PAPERS PRODUCED FROM THESE DATA ARE LISTED IN THE SELECTED REFERENCES SECTION OF THIS INTRODUCTION AND IN THE PORDATA.LIS FLOPPY FILE. THE THREE TYPES OF FILES LOCATED ON THE FLOPPY DISKS ARE AS FOLLOWS; 1) PORDATA.LIS IS A COPY OF THIS INTRODUCTION. ALSO INCLUDED IN THIS FILE IS A LISTING OF ASSIGNED COREHOLE ID NUMBER, WELL AND OPERATOR NAME, LOCATION, REPORTED J SANDSTONE INTERVAL, AND ASSIGNED FLOPPY FILE NAME FOR EACH OF THE 141 DATA FILES. 2) JSANDSTO.DAT IS A LISTING OF COREHOLE LOCATIONS, AND OF STATISTICS DERIVED FROM 135 OF THE 141 INDIVIDUAL CORE REPORT FILES. VITRINITE REFLECTANCE VALUES FOR THE J SANDSTONE IN 37 COREHOLES AND FOR 14 OUTCROP LOCATIONS ARE ALSO INCLUDED. A COMPLETE LISTING OF THE VARIABLES AND FILE FORMAT IS SHOWN BELOW. 3) EACH OF THE 141 INDIVIDUAL COREHOLE FILES CONTAINS CORE REPORT DATA. THIS POROSITY INFORMATION WAS SUPPLIED BY MORE THAN 35 OIL COMPANIES. INFORMATION CONSISTS OF CORE DEPTH, AND SANDSTONE HORIZONTAL PERMEABILITY AND POROSITY. VERTICAL PERMEABILITY AND FRACTURED ROCK SECTIONS MAY ALSO BE INDICATED IN THE DATA FILES. A LISTING OF THE FILE FORMATS AND NAMES IS INCLUDED IN THIS INTRODUCTION. FILE FORMATS JSANDSTO.DAT THE STATISTICAL FILE, NAMED JSANDSTO.DAT, LISTS THE ASSIGNED COREHOLE ID NUMBER (BLANK FOR OUTCROP VITRINITE REFLECTANCE SAMPLES), LOCATION BY LONGITUDE AND LATITUDE, CORE TOP DEPTH AND ELEVATION, MINIMUM, MAXIMUM, MEDIAN, AND HINGE POROSITY AND PERMEABILITY VALUES FOR 135 OF THE COREHOLES, AND VITRINITE REFLECTANCE VALUES FOR SAMPLED COREHOLES. HINGE VALUES ARE MEDIAN POROSITIES AND PERMEABILITIES LOCATED BETWEEN THE MEDIAN AND THE MINIMUM AND BETWEEN THE MEDIAN AND THE MAXIMUM. BECAUSE MINIMUM PERMEABILITY VALUES IN MOST COREHOLES ARE AT OR BELOW THE ANALYTICAL DETECTION LIMIT, NO MINIMUM PERMEABILITY LISTING IS GIVEN. ALL DECIMAL POINTS IN THE JSANDSTO.DAT FILE ARE IMPLIED, AND INCLUDED IN THE JSANDSTO.XLS AND JSANDSTO.CSV FILES. THE DATA FILE FORMAT FOR THE JSANDSTO.DAT STATISTICS FILE IS AS FOLLOWS; ID LONGITUDE LATITUDE DEPTH ELEV. CORE POROSITY (PERCENT) NO. (DECIMAL DEGREES) (FEET) (FEET) MIN MAX MEDIAN HINGE MIN HINGE MAX (I3) (F6.3) (F5.3) (I4) (F5.0)(F4.2) (F4.2)(F4.2) (F4.2) (F4.2) (1:3) (4:9) (10:15) (17:20)(22:26)(28:31)(33:36)(38:41)(43:46) (48:51) VITRINITE REFLECTANCE CORE PERMEABILITY (MILLIDARCIES) (PERCENT) MAX MEDIAN HINGE MIN HINGE MAX (F3.2) (F6.2) (F6.2) (F6.2) (F6.2) (FORMAT) (52:54) (56:61) (64:69) (72:77) (80:85)(COL. LOCATION) THE 141 INDIVIDUAL COREHOLE DATA FILES THE FORMAT MAY CHANGE BETWEEN INDIVIDUAL COREHOLE DAT FILES. FILES ARE ALSO SAVED AS COMMA-DELIMITED (*.CSV) AND MICROSOFT EXCEL FORMATS (*.XLS). HOWEVER, VARIABLES IN ALL FILES ARE RIGHT-JUSTIFIED, INCLUDE DECIMAL POINTS, AND ARE IN THE FOLLOWING ORDER; DEPTH (I4 OR F6.1), HORIZONTAL CORE PERMEABILITY (F7.2 OR F6.1), CORE POROSITY (F5.2), CORE FRACTURES (A1)(F=FRACTURED SAMPLE). VERTICAL PERMEABILITY, WHEN LISTED, IS LOCATED BETWEEN THE HORIZONTAL PERMEABILITY AND THE POROSITY DATA. SHOWN BELOW IS AN EXAMPLE OF A POROSITY DATA SET. DEPTH IS RECORDED AT THE TOP OF THE CORED INTERVAL. RECORDED HPERM AND VPERM VALUES THAT ARE <0.01 MD ARE LISTED AS “-1”. DEPTH HPERM VPERM POROSITY FRACTURES (VARIABLES) (1:4) (8:13) (17:22) (27:30) (35) (COLUMN LOCATIONS) 4818 142.0 11.0 19.8 F 4819 252.0 162.0 20.3 F 4820 63.0 4.6 18.9 4821 251.0 231.0 19.3 LISTING OF INDIVIDUAL COREHOLE DATA FILES THE FOLLOWING IS A LISTING OF THE WELL NAMES, POROSITY DATA FILE IDENTIFICATION NUMBERS, AND COREHOLE DATA FILE NAMES. COREHOLE DATA FILES GENERALLY, BUT NOT IN ALL CASES, ARE NAMED FOR THE FIRST TWO TO FOUR ALPHANUMERIC CHARACTERS IN THE WELL NAME AND THE TOWNSHIP NUMBER AND LOCATION (N OR S), AND ALL DAT FILES ARE TERMINATED IN ".DAT". SOME COREHOLES DO NOT CORRESPOND TO THIS NAMING FORMAT. THE FOLLOWING COREHOLE NAMES, LOCATIONS, AND DATA FILE NAMES ARE LISTED NUMERICALLY BY ASSIGNED ID NUMBER; THIS USUALLY CORRESPONDS TO INCREASING TOWNSHIP AND RANGE NUMBER. ALL INDIVIDUAL COREHOLE DATA FILES END IN .DAT. FOR EXAMPLE, THE HOUG1N ENTRY FOR ID NUMBER ONE IS LISTED ON THE FLOPPY AND THE DAT FOLDER AS HOUG1N.DAT. HOUG1N.CSV AND HOUG1N.XLS ARE IN THE CSV AND XLS FOLDERS, RESPECTIVELY. ID NUMBER WELL NUMBER AND LOCATION APPROX. TOP, FILE NAME, COMPANY SEC,TWN, RNG, 1/4 BASE CORE (FT) NAME ---------------------------------------------------------------------------- 1 #1 HOUGH, BRITISH AM. S31,T1N,R56W CSWNW 5,382-5,414 HOUG1N OIL CO. (GULF OIL) 2 #1 FRIES, PLAINS PETROL. S17,T3N,R55W SWNW 5,135-5,138 FRIE3N 3 DOLL UNIT #1-35, BASS S35,T1N,R58W NWSE 5,851-5,933 DOLL 4 ROGGEN #1, ENERGY MINS. S4,T1N,R62W, NENE 7,063-7,109 ROGG1N 5 JUNE #1, ENERGY MINS. S18,T1N,R62W 7,077-7,132 JUNE1N 6 #1 G. W. STEIBER UNIT, AMOCO S24,T1N,R67W NESWSW 8,032-8,086 ASTEIB 7 STATE #42-31, ENERGY MINS S31,T2N,R61W SENE 6,795-6,845 STAT2N 8 #34 UPRR #1, AMOCO S17,T2N,R63W NWSW 7,325-7,360 EUPRR 9 #1 GAS CORP. 14-15, AMOCO S14,T2N,R67W 990 7,997-8,043 GAS2N 10 #1 E MAX SERAFINI, AMOCO S16,T2N,R68W 7,845-7,903 ESERAFI 11 NICK SEKICH #2, AMOCO S17,T3N,R67W 7,592-7,649 NICK3N 12 #1 GEO. MATUSHIMA, AMOCO S35,T3N,R67W 7,795-7,842 GEO3N 13 SCHOOLEY #1, BRITISH AM. S9,T4N,R55W CSWNE 5,020-5,034 SCHO4N 14 #34-1 PLATTE VALLEY S34,T4N,R58W CSWSE 5,750-5,782 PLAT4N FARMS, FOREST OIL CORP. 15 BENDER #2, BRITISH AM. S12,T4N,R60W CSESW 6,268-6,309 BEND4N 16 HELEN #1, ENERGY MINS. S21,T4N,R61W SENE 6,395-6,438 HELE4N 17 YOCAM #1, ENERGY MINS. S21,T4N,R61W NWSW 6,451-6,510 BYOCAM 18 PRICE #1, ENERGY MINS. S34,T4N,R61W SENW 6,511-6,570 PRIC4N 19 LITTLER #1, ENERGY MINS. S35,T4N,R61W SESW 6,614-6,653 LITT4N 20 DUEL #1, TOM VESSELS S8,T4N,R63W NENE 7,100-7,180 DUEL4N 21 JOHN CROISSANT #1, AMOCO S11,T4N,R64W 7,186-7,256 JOHN4N 22 DAN OSTER #1, AMOCO S10,T4N,R65W NESWNE 7,545-7,580 DAN4N 23 HANSEN #1, BRITISH AM. S24,T5N,R49W CNENE 4,031-4,077 HANSEN 24 FAGG, HANK ALLEN S6,T5N,R56W NWNE 5,781-5,807 EFAGG 25 SEGEIKE #1, J. H. CHAIN S30,T6N,R54W NWSW 4,973-4,993 ASEGIK 26 CHAMPLIN 310 AMOCO 'A', S19,T6N,R62W NWNW 7,230-7,291 CHAM6N AMOCO 27 CHAMPLIN 309 AMOCO 'A' S5,T6N,R63W NWSW 7,303-7,359 CHA6N #1, AMOCO 28 CHAMPLIN 308 AMOCO 'A' S23,T6N,R64W SESW 7,303-7,358 CHAA6N #1, AMOCO 29 #1 ROBERT A. REID, AMOCO S13,T6N,R68W NWSWNE 7,441-7,491 AREID 30 STATE #16-1, JAKE HAMON S16,T7N,R58W SWNE 6,331-6,406 STATE 31 #1 LUFT B, PLAINS PETROL. S20,T7N,R51W NWNE 4,615-4,630 LUFT7N 32 HORST #1, BRITISH AM. S26,T7N,R60W CSESE 6,781-6,885 HORS7N 33 CHAMPLIN 307 AMOCO 'A' S9,T7N,R64W NWNW 7,574-7,644 CHAM7N #1, AMOCO 34 CHAMPLIN 343 AMOCO 'A' S15,T8N,R64W NWSW 7,856-7,914 CHAM343 #1, AMOCO 35 FLOYD D. WEDLEIGH S21,T8N,R68W SWSW 6,385-6,407 FLOY8N #34-21, TIGER OIL CO. 36 (D SST) MITTLESTADT S13,T9N,R54W CNENE 4,987-5,008 MITTLE D-1, BRITISH AM. OIL 37 BASHER #1, FLARE OIL S8,T10N,R61W CSESE 7,445-7,505 BASHER 38 BEAM #1, BRITISH AM. S31,T11N,R50W CSENE 4,475-4,514 BEA11N 39 ROUSSEL #1, BRITISH AM. S20,T11N,R54W CNWNE 5,342-5,388 ROU11N 40 FOSTER #1, C.C. GROSS, JR. S6,T11N,R60W NESE 7,543-7,588 FOS11N 41 FORSLING #3, WORLDWIDE E. S7,T14N,R56W SWSW 6,753-6,812 FOR14N 42 BERKEY PILE #1, WORLDWIDE S18,T14N,R56W CNWNW 6,759-6,820 BER14N 43 FORSLING-VAVRA #4, S12,T14N,R57W SESE 6,774-6,824 FORSLI WORLDWIDE ENERGY CORP. 44 #1 SIMKINS, TOLTEK S26,T14N,R59W SESE 7,505-7,529 SIM14N 45 BIRT #1-22, GENERAL AM. OIL S22,T14N,R60W NWNW 7,545-7,570 BIR14N 46 HIGDAY 1-26, HRUBETZ OIL S25,T14N,R60W SWSW 7,538-7,583 HIG14N 47 GATHMAN #5, JORDAN OIL S3,T16N,R50W 4,793-4,829 GATHMA 48 PENCE RANCH #1, AMOCO S16,T16N,R62W NENE 7,858-8,046 PEN16N 49 CHAMPLIN 301 AMOCO 'A' S17,T16N,R62W SESW 7,993-8,044 CHA16N #2, AMOCO 50 LELA YOUTZ #1, AMOCO S19,T16N,R62W SENE 7,998-8,046 LEL16N 51 #1 KING CATTLE CO. 'A', S35,T16N,R62W SENW 7,847-7,970 CATTLE AMOCO 52 BASTIAN #1, AMOCO , S20,T16N,R62W NWNE 7,936-8,022 BAS16N 53 CHAMPLIN 284 AMOCO A-1, S15,T16N,R63W SESE 8,195-8,232 CH16N AMOCO 54 UPRR "H" #1, BRITISH AM S27,T1S,R59W CSWSW 6,243-6,322 UPR1S 55 #1 MURPHY, SAMEDAN S8,T1S,R60W NESE 6,472-6,510 MUR1S 56 STATE 1-16, SAMEDAN S9,T1S,R64W NESW 6,426-6,466 BSTATE 57 UPRR 60 PAN AM 'B' #1, AMOCO S9,T1S,R64W SWSW 7,765-7,796 UPRR1S 58 #1 ABBOTT LAND CO., S12,T1S,R64W NENE 7,551-7,596 ABBO1S TOM VESSELS 59 #2 CHAMPLIN #117 AMOCO S35,T1S,R66W SWSE 8,243-8,279 CHAM1S "G", AMOCO 60 SWAN "B" #1, BRITISH AM. S21,T2S,R56W CNWSE 5,134-5,168 SWAN2S 61 JOHNSON "M" #1, BRITISH AM. S22,T2S,R56W CNWNW 5,095-5,144 JOHN2S 62 SWAN "G" #1, BRITISH AM. S27,T2S,R56W CSENE 4,987-5,040 SWA2S 63 HOFFERBER "A" #1, SUMMIT S4,T2S,R58W SWSE 6,149-6,195 HOFF2S 64 FLADER-STATE "A" #1, SUMMIT S22,T2S,R59W SWSE 6,225-6,242 FLAD2S 65 #1 EBERT "A", SUMMIT S15,T2S,R60W NWSW 6,416-6,438 EBER2S 66 #1 POPE, AMOCO S31,T2S,R62W NENW 7,340-7,398 POPE2S 67 KALLSEN #2, KOCH EXPL. S18,T2S,R65W 8,260-8,309 KALLS2S 68 EVERETTE J. DAHLINGER S4,T2S,R66W SWSW 8,315-8,380 ADAHLI #1, AMOCO 69 SHEETZ #B-1, J.W. GIBSON S14,T3S,R52W SESW 4,265-4,290 SCHE3S 70 RAYMOND THOMAS #1, GIBSON S22,T3S,R52W NENE 4,296-4,329 RAYM3S 71 SCHEETZ #6, J.W. GIBSON S23,T3S,R52W SWSW 4,277-4,304 CSHEET 72 JOHNSON #1, COCKRELL CO. S6,T3S,R53W SENE 4,682-4,696 JOHN3S 73 BLOMENKAMP #13-17, TIGER S17,T3S,R56W CNWSW 5,145-5,196 BLOM3S 74 #12-7 CHAMPLIN-DANFORD, S7,T3S,R57W SWNW 5,592-5,636 CHA3S TIGER OIL CO. 75 B STATE 42-36, TIGER OIL S36,T3S,R59W SENE 6,079-6,087 STB3S 76 STATE 32-36, TIGER OIL S36,T3S,R59W SWNE 6,069-6,086 STAB3S 77 STATE 41-36, TIGER OIL S36,T3S,R59W 6,095-6,106 STAC3S 78 #1 PRICE, SAMEDAN OIL S10,T3S,R61W NENW 6,733-6,784 PRIC3S 79 #1 CARLSON, SAMEDAN OIL S22,T3S,R61W NWNW 6,782-6,799 CARL3S 80 CALLAHAN #1, VESSELS S2,T3S,R63W NENE 7,540-7,552 DCALAH 81 #15 UPRR #1 AMOCO 'B', AMOCO S3,T3S,R63W SESE 7,544-7,569 UPRR3S 82 STATE TRUPP #16-6, S16,T3S,R63W SENW 7,671-7,732 TRUP3S SAMUEL GARY OIL 83 RHODES "A" #1, SUMMIT S26,T4S,R58W NENE 5,624-5,666 DRHODES 84 PEORIA UNIT #62, AMOCO S29,T4S,R60W 6,515-6,568 PEOR4S 85 #1 GOSS, KOCH EXPL. S15,T4S,R63W SESE 7,766-7,792 GOSS4S 86 TOM WALL #1, AMOCO S34,T5S,R59W NENW 6,128-6,184 TOM5S 87 #1 AZA BARTLETT, VESSELS S26,T5S,R60W SWSW 6,354-6,394 AZA5S 88 #1 ANDERSON-BYRNE, BWAB S23,T5S,R65W NENE 8,745-8,800 AANDER 89 CROSS #1, NORSK-HYDRO S30,T6S,R52W SWSW 4,148-4,193 CCROSS 90 #1 LOWELL, TOM VESSELS S10,T6S,R60W SWSW 6,421-6,483 LOWE6S 91 #1 SMITH ET AL, S28,T6S,R60W SWSW 6,590-6,615 SMIT6S THE ANSCHUTZ CORP. 92 FARMON L. MOCK #1 (OR S8,T6S,R61W SESE 6,957-7,002 FARM6S FERMON), AMOCO 93 #1 STORY, BWAB S32,T6S,R64W NWNW 8,707-8,724 STORY6S 94 SHELL 44-8, SHELL OIL S8,T7S,R59W 6,240-6,274 BBSHELL 95 SHELL 23-28, SHELL OIL S28,T8S,R57W 5,376-5,425 SHEL8S 96 PACKARD-STATE #1, S14,T8S,R58W SENW 5,766-5,784 PACK8S NORSK-HYDRO PETROLEUM 97 PACKARD-STATE #4, NORSK- S14,T8S,R58W 5,665-5,719 PAC8S HYDRO PETROLEUM 98 SHELL 34-17, SHELL OIL S17,T8S,R59W 6,058-6,116 SHEA8S 99 SHELL 31-22, SHELL OIL S22,T8S,R61W 7,083-7,134 SHE8S 100 TIGER OIL 14-23 RAMSEY HEIRS S23,T8S,R61W 7,013-7,072 TIGE8S 101 RAMSEY HEIRS, TIGER OIL S23,T8S,R61W NWSW 6,969-7,020 RAMA8S 102 BRANARD #1, PLAINS PETROL. S29,T8N,R53W 4,952-4,958 BRAN8N 103 BRITTINGHAM #24-35, TIGER S35,T8S,R61W SESW 7,072-7,080 BRITT8S 104 SHELL 43-6, SHELL OIL S6,T9S,R58W 5,723-5,782 SHEL9S 105 SHELL 41-1, SHELL OIL S1,T9S,R60W 6,262-6,302 SHE9S 106 SHELL 11-23, SHELL OIL S23,T9S,R60W 6,402-6,426 SHEA9S 107 SHELL 31X-8, SHELL OIL S8,T10S,R59W 6,070-6,124 SHE10S 108 SHELL 11-2, SHELL OIL S2,T10S,R60W 6,488-6,555 SH10S 109 SHELL 43-23, SHELL OIL S23,T10S,R60W NESE 6,246-6,302 SHA10S 110 SHELL 44-8, SHELL OIL S8,T11S,R59W 6,160-6,250 BSHELL 111 E-1, PLAINS PETROLEUM CORP. S22,T8N,R54W 5,252-5,264 E8N 112 MORRISON #1, PLAINS PETROL. S24,T8N,R54W 5,068-5,096 MORR8N 113 #1 JOST, PLAINS S24,T1N,R54W NWNW 4,975-4,983 JOS1N 114 #2 JOST, PLAINS S24,T1N,R54W SWNW 4,943-4,978 JOST1N 115 GOVERNMENT-HOFFMAN #1, S2,T9N,R57W CNENE 6,076-6,078 GOV9N PLAINS PETROLEUM CORP. 116 HOUGH "B" #2, PLAINS S18,T1N,R56W 5,302-5,330 HOU1N 117 MITCHELL LAND AND CATTLE S17,T2N,R54W SENE 4,859-4,876 MITC2N CO. #1, PLAINS 118 PANKONIN "A" #1, PLAINS S19,T3N,R51W SWNW 4,512-4,529 PANK3N 119 STATE "P" #1, PLAINS S14,T8N,R54W CSENE 5,096-5,118 STAT8N 120 #1 YENTER "A", PLAINS S15,T5S,R52W 4,215-4,234 YENT5S 121 SHARP #1, PLAINS S6,T1N,R53W SWSW 4,850-4,880 SHAR1N 122 SIMONSON #2, PLAINS S6,T2N,R53W CSENE 4,805-4,853 SIMO2N 123 DARBY #1, PLAINS S1,T2N,R54W CNWNW 4,787-4,819 DARB2N 124 STATE K-2, PLAINS S16,T2N,R55W CSESE 5,015-5,023 STE2N 125 #4 BONDHUS, PLAINS S19,T3N,R51W NENE 4,468-4,481 BOND4N 126 #1 ROWLAND-THOMPSON, PLAINS S26,T3N,R54W SENW 4,799-4,817 ROW3N 127 CHAPMAN #1, PLAINS PETROL. S12,T4N,R55W SESESE 4,984-4,989 CHAP4N 128 #1 QUIRK, PLAINS PETROLEUM S20,T5N,R61W NESW 6,700-6,712 QUIR5N 129 KNIGHT "B" #2, PLAINS S23,T2S,R55W SESW 4,835-4,935 KNIG2S 130 HOOD #1, PLAINS PETROLEUM S26,T2S,R55W NWNW 4,836-4,940 HOO2S 131 HOOD #2, PLAINS PETROLEUM S26,T2S,R55W SWNW 4,837-4,947 HOOD2S 132 HOOD #3, PLAINS PETROLEUM S26,T2S,R55W NENW 4,898-4,942 HO2S 133 OTTO YENTER "A" #2, PLAINS S15,T4S,R52W SWSW 4,183-4,211 YENT4S 134 SHELL #22-5, SHELL OIL S5,T7S,R61W 7,125-7,184 SHELL7S 135 STATE "0" #1, PLAINS S16,T1N,R53W NWNE 4,931-4,971 ST1N 136* HELGET #1, BRITISH AM. OIL S18,T1N,R58W CSWNW 5,996-6,022 HELG1N 137* STATE 16-2, JAKE L. HAMON S16,T7N,R58W NE 6,394-6,403 STAT7N 138* RAMSEY HEIRS 32-26, TIGER S26,T8S,R61W SWNE 7,052-7,064 RAM8S 139* SAFRANEK-STATE #1, NORSK- S30,T19S,R56W NESW 4,790-4,812 SAF19S HYDRO PETROLEUM 140* CHALLIS FARMS #1, PLAINS S31,T1N,R53W NENW 4,946-4,965 CHAL1N 141* #2 STATE-U, PLAINS S36,T1N,R54W SWSW 4,948-4,962 STAT1N * IDENTIFICATION NUMBERS WERE NOT ASSIGNED BECAUSE STATISTICAL DATA FOR THESE COREHOLES ARE NOT INCLUDED IN THE JSANDSTO.DAT FILE. SELECTED REFERENCES HIGLEY, D. K., PAWLEWICZ, M. J., AND GAUTIER, D. L., 1985, ISOREFLECTANCE MAP OF THE J SANDSTONE IN THE DENVER BASIN OF COLORADO: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 85-384, 100P. ______, AND GAUTIER, D. L., 1985, REGIONAL TRENDS IN POROSITY AND PERMEABILITY OF THE J SANDSTONE-- CONTROLS OF BURIAL HISTORY: AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS BULLETIN, VOL 69, NO. 5, P. 851. ______, AND ______, 1986, MEDIAN-PERMEABILITY CONTOUR MAPS OF THE J SANDSTONE, DAKOTA GROUP, IN THE DENVER BASIN, COLORADO, NEBRASKA, AND WYOMING: U.S. GEOLOGICAL SURVEY MISCELLANEOUS MAP FILE SERIES 1837, 1 SHEET. ______, AND ______, 1987, MEDIAN-POROSITY CONTOUR MAPS OF THE J SANDSTONE, DAKOTA GROUP, IN THE DENVER BASIN, COLORADO, NEBRASKA, AND WYOMING: U.S. GEOLOGICAL SURVEY MISCELLANEOUS MAP FILE SERIES 1982, 1 SHEET. 1