Oilandgasdiscouery
wellsdrilled
in NewMexico
in lggg
byRonald
F.Broadhead,
NewMexico
Bureau
of Mines
andMineral
Resources,
socono,NMg7g01
i"L*
aa
$ari Juan
Cui{ax
Raton
Easin
*-a
3
hdc
Ispano!a
Basin
I
l
"_ A
5an
lJiiguel
-16
17v
I Cihsla
i*
.* *,*-
Eaca
Basin
15x
Y
Introduction
More wells were drilled for oil and gas in
New Mexico in 1988than in 1982.Da[a obtained from the New Mexico Oil Conservat i o n D i v i s i o n i n d i c a t e 1 , 0 4 3w e l l s w e r e
completedin 1988,up 11%from the 938wells
completed in 1987but down 64Vofrom the
record2,867wells completedin 1981.In the
Permian Basin, southeastNew Mexico, 238
wells were completed in 1988,down from
740completionsin 1987;435wells were completed as oil producers,139wells were completed as gas producers,and 164wells were
plugged and abandoned,resulting in a success rate of 78Vo.In the San fuan Basin,
northwest New Mexico,305wells were comRlgted in 1988,up from 198completionsin
1987;74 wells were oil producers,176wells
were gas producers,and 55 wells were
plugged and abandoned,resulting in a successrateof 82Vo.Inaddition,two wellswere
completedin the Bravodome carbondioxide
gas field of southern Union and eastern
Harding Counties.
Total footage of hole drilled in 1988was
5,3M,474ft, up from 4,767,394ftin 1987.The
averagedepth of wells drilled in 1988was
5,724 ft, 41 ft more than the averagedepth
drilled in 7987.
Alsoin thisissue
Jv
O
#
O
50
50
lOO mi
1OO
|5O km
^.
H
D t g n l l r c a ngt a s d i s c o v e r y
I
Significano
t il discovery
$
S i g n i fi c a n td r y h o l e w i r h o i l a n d g a s s h o w
A
wagon Mound gas pool
Q S i g n i f i c a n td r y h o l e w i t h o i l s h o w
$ ' Significant dry hole without reported
snow
I
B
Newkirk oil pool
g
f
C
S a n t a R o s at a r s a n d s
I
Significant wildcat well drilling, not
completed,"tight", or plannedat end of
19 8 8
FIC,URFl-Significantoil and gas discoveriesand wildcat wells drilled in New Mexico in 19gg.Major
geologic featuresare taken from Broadheadand King (1998).Cather and
Johnson (19g4),Kelley (19y'g),
Kottlowski an^dstewart (t920), Meyer (1966),Moleniai pizy Thompson andyacia
iryoodl
4rsar1,
ward et al. (1978).
".,i
Statetaxeson natural
resourceproduction
Subscription
information
RfSr valuesin MogollonDatilvolcanicfield
Dept.ofEarthSciencesat
NMSU
Service/News
NMGS News
Index to Volumell
Staff notes
p.75
p. 75
p. 76
p. 84
p. 85
o. 86
p.87
p. 88
Goming
soon
Reviewof Mesozoicnomenclature
EagleNest-GraniteHill arearocks
FentonHillgranodiorite
parenthesesthat refersto its locationin FigThe downturn in drilling over the past
ure 1 and its descriptionin Tables1,2, ot 3.
seven years has been accompanied by seriefforts.
Several
exploratory
decreased
ously
major oil companies announced reduction or
Southeast New Mexico
elimination of onshore exploration efforts in
Drilling activity remained slow in 1988 in
the United States. Despite this, however, sigthe three geologic subdivisions of the Pernificant exploratory drilling continued in the
mian Basin: the Delaware Basin, the Central
Baca, Estancia, and Tucumcari Basins and in
Basin platform, and the Northwest shelf.
the Gallup-Zuni sag west of the Zuni uplift
Drilling activity was also light on the Roose(Fig. 1). Locations were staked at the end of
velt uplift. Despite the slow drilling activity,
1988 for frontier wildcat wells to be drilled
however, the Permian Basin yielded several
in eastern Socorro County, north-central Otero
significant oil and gas discoveries in 1988 (Fig'
County, Taos County, westem Cibola County,
1; Table 1). McKamey (1988)presented stratiand northeast Rio Arriba County.
For purposes of this report, a significant graphic charts of oil- and gas-producing rock
units in southeastern New Mexico, as well
wildcat discoaeryis defined as a well in which
as geologic summaries of recently discovered
commercial amounts of oil or gas were discovered in a stratigraphic unit more than 5 oii and gas pools.
The Delaware Basin, the deep marine part
miles from the limits of previously discovof the Permian Basin, yielded four significant
ered pools with commercial production from
that stratigraphic unit. A significant wildcat discoveries in 1988. Gas was found in Cisco
strata (Pennsylvanian) in the BTA Oil Prodru hole is defined as a drv hole that was
ducers No. 1 8710 jV-P Tank B (L). Gas was
dritted in a not-yet-productive basin or a part
of a basin and in which petroleum reservoirs found in Wolfcamp strata (Permian) in the
Enron Oil & Gas No. 1 Harkey State 35 (2).
were evaluated. The locations of significant
wildcat wells that were completed in 1988 The Wolfcamp also yielded a significant oil
discovery in the Enron Oil & Gas No. 1 Queen
are shown in Figure 1. Table 1 summarizes
the significant wildcat discoveries and Table Lake Federal 20 (3). Oil was discovered in
basinal Brushy Canyon sandstones of the
2 summarizes the significant wildcat dry
Delaware Mountain Group (Permian) in the
holes. Table 3 lists other significant wildcat
wells that were being drilled, were not com- Pogo Producing No. 1 Neff Federal 13 ( ).
Because of the relatively slack gas market,
pleted, or were held "tight" at the end of
exploration in the Delaware Basin was con1988.
centrated primarily on finding new oil reEach well is designated by a number in
wildcat discoveries in New Mexico in 1988; the term formation is used in an
TABLE l-significant
informal re.rse. BOPD, bbls oil per day; BWPD, bbls water per day; MCFGPD, thousand fti gas per
day; IB initial potential; IPD initial potential, flowing; IPB initial potential, pumping; IPCAOB initial
potential, calculated absolute open flow; NR, not released; owwo, old well worked over.
Number
Fi8. 1
Ltration
(FctioF
townshiprrn8e, county)
34-23S 24E,
Eddy
Completion
drt€
(mo/yr)
Op€r.tor,
w:ll iusbe.,
ed lea*
BTA Oil
Producers No. I
8710 fV-P Tank
B
Total
d€pth
(ft)
at
total depth
PrcducinS
formation
ProducinB
inteilal
(f0
tnitial
pot€ntial
Cisco
8,036 8,120 IPF 724
9,975 Barnett
MCFGPD
(Mississippian) (Pennsyl.ranian)
12,920 Morrow
(Pennsylvanian)
Wolfcamp
(Permian)
10,36410,380IP416
MCFCPD
20 249 29E,
Eddy
Enron Oil &
Cas No. 1
Queen Lake
Federal 20
12,390 Atoka
(Pennsylvanian)
Wolfcamp
(Permian)
9,884 10,034 IPF 47 BOPD
+67
MCFCPD +
171BWPD
13-229 37E,
Eddy
Pogo Producing
No. 1 Neff
Federal l3
14,975 Morrow
(Pennsylvanian)
Delaware
(l'ermian)
7,119-7,158 IPF 232
BOPD + 160
MCFCPD +
131BWPD
9 145-298,
Chaves
Santa Fe
Exploration No.
l Holmstrom
Federal
9,758 Devonian
Devonian
9,728 9,7s8 rPF,n3
BOPD + 14
MCFCPD
29-79-31E,
Chaves
Robert N.
Enfield No. 1
McCombs E
9,182 Precambrian
Devonian
8,4Z/ 8,551 TPCAOF
1,802
MCFGPD
Dugan
Production
Corp.No.1
Ollie
2,200 ticlureJ Cliffs
(Cretaceous)
Fruitldnd
PicturedCliffs
(Cretaceous)
2,0842.,U)1; IPP 35
MCFCPD +
2,0912,$6
25 BWPD
Meridian Oil
lnc. No. I
Luthy (owwo)
2,207 Pictured Cliffs
(Cretaceous)
fruitlan.
(Cretaceous)
1-26N-8W,
San Juan
November
1989
New AAexnc@
GEOLOGV
. Science
andService
volume
11, No.4,
November
1989
Editor: Carcl A. Hjellming
Published quarterly bY
New Mexico Bureau of Mines and Mineral Resources
a division of New Mqi@ Institute of Mining & lbchnology
35 245 27F,, Enron Oil &
Eddy
Cas No. 1
Harkey State 35
30-24N-ZW,
Rio Arriba
Oil gravity
(degre6
API)
serves;lesseffort was concentratedon finding
new gas reserves. Major targets for oil exof the Bone
plorationwere basinalsandstones
Spring Formation and Delaware Mountain
Crouf (Permian) and Wolfcamp carbonate
reservoirs(Permian).Exploration for gaswas
c o n c e n t r a t e dm o s t l y i n C i s c o , C a n y o n ,
Strawn, Atokan, and Morrowan reservoirs
(Pennsylvanian). There was limited exploft)
ration ior oil in the deep (10,000-13,000
Silurian and Devonian carbonatereservoirs.
Development drilling in the Delaware Basin was mostly for oil in 1988.Major targets
for development drilling were oil reservoirs
in the shallow (4,000-6,000ft) Delaware
Mountain Group (Permian)and moderately
deep (6,000-10,000ft) Bone Spring Formation (Permian).Developmentdrilling for gas
ft) Atokan
was mostly in deep(10,000-14,000
and Morrowan (Lower Pennsylvanian)clastic units.
No significant wildcat discoverieswere
made on the Central Basinplatform in 1988.
E x p l o r a t i o n w a s c o n c e n t r a t e do n d e e p
ft) Silurianand Devoniantar(10,000-12,000
getsunder the platformand alongthe west6rn border areas of the platform. Several
exploratorywells were drilled for this purposeand severalold abandonedwells were
ie-entered with attempts to recomplete for
Silurian and Devonian discoveries.Development drilling was mostly for oil in the
shallow (2,000:5,000ft) Queen and Crayburg sandstones(Permian)and San Andres
Nao Mexico Ceology
1,964 2,1.05 NR. Cas
well.
46.6
36.5
BOARD OF REGENTS
Ex Ofticio
Carrey Canuthers, Couernorol Nru Mextco
Alan Morgan, Suryrintendefltof Publiclnstruction
APPointed
Lenton Malry Pres.,1985-7991,Albu4uerqw
Robert O. Andemon, Sr.lTreas.,1 7-1993, Roswll
Lt. Cen. Leo Marqtez, 1989-1995,Alhuqueryue
Carof A- Rymer, M.D. 1989 1995,Albuquerque
Steve Torres, 1967-1991,Albuquerque
New Mexico Institute of Mining & Technology
....
LaurenceH.lattman
Pfesidilt..
Nw Mexico Bureau of Mines & Mineral Resources
Diector and StflteGeologist . . . . Frank E. Kottlowski
Astuciate Director
James M. Robertson
Sub$riptions:lssued quarterly, February. May, August,
November; subrription price $6.00/calendaryear.
EditorialMttq: Articles submitted for publication should
be in the editor's hands a minimum of five (5) months
before date of publication (February, Mat August, or
November) and should be no longer than 20 typewritten, double-spacedpages.All scientific PaPerswill be
reviewed by at leasttwo PeoPlein the aPProPriatefield
of study. Addressinquiries to CarolA. Hjellining, Editor
ol Nru Mexia Geology,New Mexico Bureau of Mines &
Mineral Resources,Smorrc, NM 87801
Publishedas public doruin, thzr4orc reprcducible@ithoutPq
mission.Sourcecreditreqwted.
Circulation:1,6fr
Prirter: University of New Mexico Printing Plant
carbonates(Permian). Sirgo-Collier, Inc.
continued extensive development of a waterflood unit in the Dollarhide Queen oil pool
of southeastLea County. Chevron continued
its infill drilling program of the EuniceMonument Grayburg-SanAndres oil pool of
east-centralLea Counfy. Other targetsof development drilling on the Central Basin platform were oil reservoirs in the Blinebry, Tubb,
and Drinkard zones of the Yeso Formation
(Permian).
Two significant wildcat discoveries were
made on the Northwest shelf in 1988. Oil
was found in Devonian reservoirs in the Santa
Fe Exploration No. L Holmstrom Federal(5).
Gas was found in Devonian reservoirsin the
Robert N. Enfield No. 1 McCombs E (6) in
east-centralChaves County.
In contrastwith other parts of the Permian
Basin, development drilling of oil and gas
pools on the Northwest shelf continuedat a
relatively brisk pace during 1988.Major tarBetswere oil reservoirsin the shallow (2,0fi)6,0N ft) Grayburg and San Andres Formations (Permian).Conoco and Phillips continued extensive infill drilling programs in the
Maljamar Grayburg-San Andres oil pool of
northwest Lea County. Conocobeganits second carbon dioxide flood in the Mallamar
pool early in 1989.Phillips continued its extensive infill drilling program in the Vacuum
Grayburg-San Andres oil pool of northwestem Lea County. There was limited development of deepei oil reservoirs:Wolfcamp
(Permian) carbonates,Pennsylvanian carbonates, and Ordovician carbonates.
The only gas pools extensively developed
on the Northwest shelf in 1988were the Pecos SlopeAbo and West PecosSlopeAbo gas
pools of northwest and north-central Chaves
County. More than 50 infill wells and extension wells were drilled in those pools, which
produce from "tight" fine-grained red beds
of the Abo Formation at depths of 3,5005,000 ft. Production from most of the 6fi)
wells in the Ato gaspools was shut in during
early fune when it was discoyeredthat trace
amounts of arsenic were present in the Abo
gas. Wells which connected to Enron Corporation's Transwestem pipeline were shut
in; most Abo gas is transported to customers
in California through this pipeline. Arsenic
concentrations were estimated to be 500 micrograms/m'for gas delivered to the Transwestern pipeline and 0.05 ppb for gas
delivered to the El PasoNatural Gas pipeline
that servesthe area (Slaton, 1988).Nine gastreatment units were installed in the Pecos
Slope Abo pools. Those treatment units remove the arsenicfrom the gasbefore it enters
the main pipeline (Slaton, 1989). Abo gas
production resumed in December,1988.
The Rooseveltuplift and adjacentareaswere
drilled sparsely in 1988.No significant wildcat discoveries were made. Development
drilling was concentratedon oil reservbirsin
the southern part of RooseveltCounty; primary targets were in the Todd San Andres
oil pool and the North Bluitt SilurianDevonian oil pool. Development of Ordovician and Pennsylvanian reservoirs in the
TABLE 2-Significant wildcat dry holes drilled in New Mexico in 1988;the term formation is used in
the informal sense.D&A, dry and abandoned;perf, perforated; acid, acidized; owdd, old well drilled
deeper; OTD, old total depth; TD, total depth.
Number
on
Fig. r
Location
(sdioFtownship
nnge, county)
l1
t3
lo
i
f
I
Operator,
well number,
and l€as
l6-14N-328,
Harding
Michael K. Galvis No. 1
StateHGH
l6-13N-34E.
Quay
31-13N-308,
San Miguel
Completion
dat€
(month./
yeatt
718€
Total
depth
(ft)
Fomtion
at
total depth
Status
Comments
1,098 San Andres
(Pemian)
D&A
Lost circulation in San
Andres Formation
(Permian).
Esperana Energy No. I
Logan State
3,600 Prcambrian
D&A
Perf & acid 3,2201,3n It
& 3,190-3,200ft (granite)
with no show. Perf &
acid 3,112-3,120ft (Abo)
with no show. Perf 2,5982,622ft (Tubb) with no
show.
Tom L. lntram No. 1
Gihon (owdd)
4,7114Precambrian
D&A
Testedseveralzones; no
details available.Old well
completedin 1986.OTD
2,579ft in Yeso
(Pemian).
6-3N-7E,
Torrance
Bruce Wilrcn No. lX Judd
2,8,{0 Permian
Perf & acid 1,628-1,6U ft,
1,876-t,82 ft, 2,2462,252,2,4q-2,4M ft
(Permian).Oil & gas
show reported.
12JN_6E,
Tocance
fohn Aday No. 2 D'Spain
1.900 Pennsylvanian D&A
Spudded in 1983.TD
reachedin 1984.
Abandoned in 1988.
27-15-13W,
Catrcn
Shell Westem Exploration
& Production No. 1 SWEPI
et al. Aspen Federal
9,000 Precambrian
D&A
"Tight" hole. No reported
21JS-1sW
Catrcn
Shell Westem Exploration
& Production No. 1 SWEPI
et al. Mangas Mountains
Federal
7,808 Prcambrian
D&A
"Tight" hole. No reported
shows. TD reachedon 11/
70187.
28-r1N-rew,
McKinley
Bun Oil & Gas No. 1 Zuni
1,885 Yeso
(Permian)
D&A
lpst circulation at 1,110 ft
(San Andres).
Encountered wet oil in
San Andres (Pemian),
mlt water in Glorieta
(Pemian), and salt water
and oil in Yeso (Pemian).
Unable to drill deper or
run drill-stem test
because hole caved in.
Drilled on Pinon Springs
anticline.
r2187
Tule gasfield of northwest RooseveltCounty
continued.
in 1988 was coal-bed methane in the Fruitland Formation (Cretaceous).Most exploratory well completions were made by reNorthwest New Mexico
entering older wells that had previously proIn L988, 305 wells were completed in
duced from Cretaceousreservoirspresent at
northwest New Merjco, up from 198 com- Breaterdepths than the Fruitland.
pletions in 1987but down from 405 compleMost development drilling in the Sanfuan
tions in 1986 and 863 completions in 1985. Basin was for coal-bedmethane in the FruitThe diminished rate of drilling since1986has land. Kelso et al. (1988)estimatedthat the
been caused by depressedgas prices and a total gas contained within Fruitland coal beds
depressed market for gas, which is the priin the San fuan Basin is 50 trillion fP (TCF);
mary petroleum product of the Sanfuan Ba- most of that gas is within the New Mexico
sin. Depressed oil prices have also taken a part of the basin. More than 120 developtoll on drilling activity in the SanJuan Basin. ment wells and pool extension wells were
Exploratory drilling resulted in two sig- completed in the Fruitland in 1988.Fruitland
nificant discoveriesin 1988.Gas was discov- , gas reservoirs have been ignored for many
ered in Fruitland coal beds and the Pictured years because of low production volumes;
Cliffs Sandstone (Cretaceous)in the Dugan exploration and development have been
Production Corp. No. 1 Ollie (7). Gas was concentrated in deeper, more prolific reserdiscovered in Fruitland coal beds during a voirs in the Upper Cretaceous. However,
workover of the Meridian OiI Inc. No. 1 Luthy
lower costs involved with drilling the shal(8), an abandoned Pictured Cliffs gas weli.
lower Fruitland reservoirs (approximately
Exploration was concentrated in the north2,000 ft deep) compensatepartially for the
central part of the basin in easternSan fuan
low volumes of gas production. More imand westem Rio Arriba counties. The prinportantly, producers are eligible for a federal
cipal exploration target in the SanJuan Basin gas-production tax credit for wells drilled be-
New Merio Geolo3y November 1989
TABLE 3-signifignJ wildcat wells that were being drilled, not completed, "trght" , or planned in New
Mexico at the end of 1988.owwo, old well worked over.
Number
on
Fit. 1
Location
(section-townshiprange, county)
17
27-8N-18W, Cibola
18
2-30N-3E, Rio
Aniba
Operator,
well number,
and lease
Comments
Menion Oil & Gas No. I
Galestina Canyon
Drilled to total depth of 2,770 It. Perforated
Permian. "Tight" hole.
Heyse Oil No. 1 Rio
Chama
Scheduled to drill to 2,000 ft to PrtramDnanDrilled to total depth of 254 ft then shut down due
to mehanical problems.
10-30N-7W, Rio
Aniba
Blackwood & Nichols
Co. No. 501 Northeast
Blanco Unit
Drilled to 8,956 ft to test Entrada (lurassic). Tested
Entrada, Bluff, and Morrison with no reported
shows. Converted to water injection well.
19-31N-3E, Rio
Aniba
Spur Oil No. 1 South
Location staked. Scheduled to drill to 1,100 ft to
test Entrada (Jurassic).
29-32N-3E, Rio
Aniba
Spur Oil No. 1 Quinlan
Ranch 29
Drilled to total depth of 3,865 ft in Entrada
(Jurassic). Perf Crenhom
(Cretaceous) from 2,340
to 2,370 tt.
17-27N I7tN, San
Juan
Chuska Energy No. 1
Table Mesa Navajo
Tribal
Location staked. Scheduled ro drill to 8,300 fr to
test Mccracken Sandstone (Devonian).
13-30N 21W, San
Juan
Chuska Energy No. 2
Beclabito (owwo)
Location staked. Scheduled to test Mccracken
Sandstone (Devonian) at 5,000 ft.
1 4F38, Socoro
fames K. Anderson No.
1 Wishbone Federal
Scheduled to drill to 4,000 ft to test Permian and
Pennsylvanian sections.
35-24N-148, Taos
Conoco, lnc. No. 1 Taos
Trough Unit
Scheduled to drill to 6,000 ft to test Pennsylvanian
s(tion.
Location staked in 1986. Operator changed
from Leonard Minerals.
15-2S-28E,De
Baca
Esperanza Energy No. 1
McClain Ranch
Scheduled to drill to 3,000 ft to test Glorieta
Sandstone (Permian).
7-145-11E,Otero
Cibota Energy No. 1
Ysletano Canyon Federal
fore fanuary l, I99L; that tax credit applies
to gas produced from those wells prior to the
year 2000. As a result of the tax credit, a
drilling boom started as operators rushed to
develop their reserves before the deadline.
Meridian Oil Company and Amoco Production Company are the major operatorsin the
coal-bed methane play; Nassau Resources,
Southland Royalty, Northwest Pipeline,
Blackwood & Nichols, and Union Teias Petroleum also have significant holdings and
have drilled wells within the New Mexico
part of the San Juan Basin (Neil H. WhiteheadIII, personalcommunication1989).Other
significant targets of development drilling for
natural gas in 1988were the Pictured Cliffs
Sandstone(Cretaceous),sandstonesin the
MesaverdeGroup (Cretaceous),and the Dakota Sandstone(Cretaceous).
Although developmentdrilling for oil was
subordinate to development drilling for gas
in 1988, significant efforts were still made.
Major targets of development drilling for oil
were the Gallup and Dakota Sandstones
(Cretaceous)and the lower part of the Mancos Shale (Cretaceous).Effort was concentrated in the Bisti Gallup, South Bisti Gallup,
Lybrook Gallup, and West Lindrith GallupDakota oil pools.
Production in the SanJuan Basin is almost
entirely from Cretaceous reservoirs. Relatively minor amounts of production are obtained from stratigraphic traps in the Entrada
Sandstone(furassic)in the southeasternpart
of the basin and from Pennsylvanian, Mississippian,and Devonianreservoirsin structural traps along the western flank of the
November 1989 New Mexico Gmlogy
exploratory wells were drilled in the GallupZuni sag. The Gallup-Zuni sag is a synclinal
feature on the west side of the Zuni uplift;
it connects the San Juan Basin and the Baca
Basin. The Merrion Oil & Gas No. 1 Galestina Canyon (17)was drilled on a prominent
anticline to a total depth of 2,770 ft. Production casing was set and perforated. The well
was "tight" in early L989, but apparently
commercial production was not established.
Farther to the north, the Burr Oil & Gas No.
1Zuru(1,6)was spudded on the PifronSprings
anticline and subsequently drilled to a total
depth of 1,885ft in the YesoFormation(Permian); oil shows were reportedly encounteredin the SanAndresFormation(Permian)
and in the Yeso. The well was abandoned
becausethe hole cavedin. The Piflon Springs
anticline remains poorly tested.
The Burr well was drilled as part of an
exploration agreement made by the Zuni
Pueblo with Burr and High Plains Petroleum
Corp. The agreement covers an exploration
area of more than 20,000acres.Under the
terms of the agreement,two additional weils
will be drilled in southwestern McKinley
County during 1989.One well will test the
Wompia Springs anticline and the other well
will test the Galestina monocline.
Northeast New Mexico
Petroleum exploration continued in the
frontier areas of northeast New Mexico in
L988.Three wildcat wells were drilled in the
basin. Significant exploration focusedon Jur- Tucumcari Basin and two wildcat wells were
assic and Paleozoictargets in 1988,but the plugged in the EstanciaBasin. Development
Jurassic and Paleozoic remain essentially of the Bravo dome carbon dioxide gas field
frontiers for petroleum exploration.
continued. Petroleum has not been proIn the central part of the basin, the Black- duced commercially in northeast New Mexwood & Nichols No. 501 Northeast Blanco ico exceptduring a brief period in the 1970's
Unit (19)was drilled to a total depth of 8,956 when marginally commercialamounts of gas
ft; Entrada, Bluff, and Morrison sandstones were produced from the Morrison Formation
(Jurassic)were tested without reported (furassic) and Dakota Sandstone(Cretashows. In the easternmostpart of the basin, ceous)at the currently inactiveWagonMound
which is also known as the Chama Basin,the field in Mora County (Fig. 1, letter A). In the
Spur Oil No. L Quinlan Ranch 29 (21)drilled
t980's, the Newkirk pool (Fig. 1, letter B) has
to a total depth of 3,865 ft in the Entrada produced 508 bbls heavy oil from the Santa
Sandstone; the Greenhorn Limestone (Cre- Rosa Formation (Triassic)with the aid of a
taceous)was testedwithout reported show. pilot steamflood project. McKallip (1987)reThe Heyse Oil No. 1 Rio Chama (18) was ported on the geology of the steamflood
scheduled to reach a total depth of 2,000 ft
project in the Newkirk pool. In the 1930's,
in Precambrian, but drilling was terminated approximately 153,000tons of tar sandswere
at a depth of 254 ft becauseof mechanical mined from the Santa Rosa Formation near
problems with the rig; it remains unknown
the town of SantaRosain GuadalupeCounty
if the operator plans to resolve those prob- (Gormanand Robeck,t946;Fig. 1, letter C).
lems and continue drilling. Farther north,
In the EstanciaBasin of TorranceCountv,
location was staked for the Spur Oil No. 1 the Bruce Wilson No. 1X fudd (12), whiih
South (20) which reportedly will be drilled
had been drilled in 1987,wasplugged in 1988.
to a total depth of 1,100ft to test the Entrada. The No. 1X Iudd had been drilled to a total
Along the western flank of the San |uan
depth of 2,840 ft in the Abo red beds (PerBasin, Chuska Energy entered into an explo- mian). Oil and gas shows were reported,
ration agreementwith the Navajo Nation on presumably in the Yeso or Abo Formations
their reservation. As a result of that agree- (Permian).The fohn Aday No. 2 D'Spain (13)
ment, locationsfor two wells (22,23) were was finally plugged; the well was spudded
staked. Those wells are scheduledto drill to in 1983and had been drilled to a total depth
the McCrackenSandstone(Devonian),which of 1,900 ft by April, 1984. No shows were
unconformably overlies Precambrian base- reported.
ment. Presumably, carbonate reservoirs of
Exploratory activity continued in the TuPennsylvanianand Mississippianageare also cumcari Basin in 1988.Drilling was concenexploratory targets in those wells.
trated along the northern margin of the basin.
Elsewherein northwest New Mexico. two
The Michael K. Galvis No. 1 State HGH (9)
Scheduled to drill to 3,800 ft in Devonian
Location staked in 1986.
strata.
was drilled to a total depth of 1,098 ft in
granite wash (Pennsylvanian) and subsequently abandoned. No shows were reported in this well; circulation was lost in the
San Andres Formation (Permian).The Esperanza Energy No. 1 Logan State(10)was
drilled to a total depth of 3,600ft in Precambrian basement.The Precambrian,a sandstone in the Abo Formation (Permian), and
the Tubb sandstone (Permian) were tested
through casing perforations, but no shows
were reported. The Tom L. Ingram No. 1
Gihon (11;Fig. 2) was re-enteredand deepened in 1988.The well had originally been
drilled to a total depth of 2,579ft in 1986and
was a San Andres (Permian)test. It was reentered in 1988 and drilled to a new total
depth of 4,74 ft in Precambrianbasement.
Apparently, severalzoneswere testedbefore
the well was abandoned,but detailsof completion and testing operations are not available.Broadheadand King (1988)reportedon
the petroleum geologyof the TucumcariBasin.
Exploratory activity was quiet elsewhere
in northeast New Mexico. No wells were
drilled in either the Raton or SanLuis Basins.
However, the clastic Cretaceoussection of
the Raton Basin has considerablepetroleum
potential and wells drilled into the Cretaceous in past years have encountered significant and promising shows of gas. Speer
(1976) and Woodward (1987)discussed the
petroleum geology of the Raton Basin.
A location remained stakedfor the Conoco
No. 1 TaosTrough Unit (25)in the Sangrede
Cristo Mountains. The location was originally stakedin 1986by Leonard Minerals; the
operator was subsequentlychanged to Conoco. The well will spud in the Pennsylvanian
section and is scheduled to be drilled to a
total depth of 6,000ft. The No. 1 TaosTrough
Unit will be the first petroleum exploration
well drilled in Taos County.
Development of the Bravo dome carbon
dioxide gas field of southern Union and
southeastemHarding Counties continued at
a slow pace.In 1988,two wells were drilled.
The main reservoir at Bravo dome is the Tubb
sandstone(Permian),which lies at depths of
approximately2,000ft. Minor production is
obtained from SantaRosasandstones(Triassic). Most carbon dioxide produced from the
Bravo dome field is used for enhanced oil
recovery in the west Texaspart of the Permian Basin. Eventually, as production wanes
from oil fields under waterflood in the New
Mexico part of the Permian Basin, carbon
dioxide will be used increasingly for enhanced oil recovery in the New Mexico part
of the Permian Basin.The demand for carbon
dioxide in both New Mexico and Texaswill
increase. Exploration for additional carbon
dioxide reserves in northeast New Mexico
will be needed.
Southwest New Mexico
Two significant wildcat wells were abandoned in the BacaBasinof southwestemNew
Mexico during 1988.The Shell Western Exploration and Production No. I SWEPIet al.
Mangas Mountains Federal (15) was drilled
Oil and gas production
lnl987, New Mexico was the seventhlargest producer of crude oil and the fourth largestproducerofnatural gasin the United States
(Energy Information Adminishation, 1988).
Production of crude oil and leasecondensate
in New Mexico in 1988 was approximately
71.2million bbls, a decreaseof 1.5Vofrom the
72.3 million bbls produced in 1987 (New
Mexico Oil ConservationDivision data). Production of natural gas in 1988was approximately 781 billion ff (BCF), a decreaseof
4.0Vofrom the 813BCFproducedin 1987.In
1987,89Voof the state'soil and 52Voof the
state's gas were produced from the Permian
Basin; LlVo of the state's oil and 48Voof lhe
state's gas were produced from the San|uan
Basin.As of December31,1987,New Mexico
had proved crude oil reservesof 654 million
bbls oil, an increaseof 10 million bbls from
December 3t, 1,986(Energy Information
Administration, 1988); the Permian Basin
contains 93Voof the state's proved oil reserves and the San |uan Basin contains 7Vo
of the state's proved oil reserves.Additionallv New Mexico had reservesof 63 million
FIGURE2-Tom L. lngramNo. 1 Gihon (Fig. 1, bbis of leasecondensateas of December31.
no. 11;Table1, no. 11)drillingon the northern 1987 (Energy Information Administration,
marginof the TucumcariBasin,fanuary1988.
1988);75Vo
of the state'scondensatereserves
are in the San Juan Basin and 25Voof the
to a total depth of 7,808 ft during 1987 and state's condensate reserves are in the Perwas subsequently abandoned without re- mian Basin. As of December31, 1.987,New
ported shows. The Shell No. 1 SWEPIet al. Mexico had proved natural gas reserves of
Aspen Federal(14)was drilled to a total depth
12.5trillion ft' (TCF),an increaseof 0.1 TCF
from December31,,1986(EnergyInformation
of 9,000ft and abandonedin 1988.Both wells
are "tight." They were drilled in a federal Administration, 1988); the San |uan Basin
explorationunit known as the "MagicArea." contains 75Voof the state's gas reservesand
This exploration unit was formed by a con- the Permian Basincontains 25%of the state's
sortium of Shell, StandardOil (Sohio, now
gas reserves. Those reserve estimates apBP Exploration), and Elf Aquitaine in 1986 parently do not include coal-bedmethane in
and covers approximately3.5 million acres the Cretaceousof the San Juan Basin. Kelso
in northern Catron and western Socorro et al. (1988)stated that coalsin the Fruitland
Counties. A third well, the Shell No. 1 ManFormation (Cretaceous)contain an estimated
gas Mountains Federal, located in Sec. 21., 50 TCF gas in place in the San juan Basin;
T3S, R15W, Catron County, was drilled and
approximately 707oof that gasis locatedwithin
abandoned in 7987. Extensivereflection seis- the New Mexico part of the basin. It is not
mic surveys have been run by the consor- known what percentageof the coal-bed
tium in the Magic Area. The Shellexploration methane is recoverable.
and drilling program constitutes the first
The decreasein oil production in 1988can
comprehensiveeffort to evaluateand test the be attributed to a decline in the price of crude
petroleum potential of centralCatron County. oil since January 1986(Fig. 3). The posted
Primary targets in Catron County are Upper
price of west Texas intermediate crude oil
Cretaceoussandstones,the SanAndres For- with a gravity of 40'API (the "benchmark"
mation, GlorietaSandstone,sandstonesand crude oil of the United States)fell 55% from
carbonatesin the YesoFormation (Permian), $27.251bb1infanuary 1986to $12.25lbblin
and Pennsylvanian sandstonesand lime- july 1986. The price subsequently rose to
stones.
$20.00/bbl in August 7987 and then fell to
In eastern SocorroCounty at the northern
$l3.75lbbl in November 1988.Since the end
end of the jornada del Muerto, plans were of 1988, posted prices for west Texasintermade to spud the |ames K. Anderson No. I
mediate crude have risen to $l7.75lbbl in
Wishbone Federal (24). That well will be March 1989(Oil and Gasloumal, 1989a),when
drilled on the Prairie Springs anticline and this article was written.
is scheduled to drill to Precambrian baseThe sharp fall in oil prices at the'bpginning
ment at a depth of 4,000ft. Primary targets of 1986was due to a sudden rise ih oil proare Pennsylvanian sandstonesand lime- duction by several major produCing counstones.
tries (notably Great Britain and Latin
No exploration wells were drilled else- American and Middle Eastern countries) in
where in southwest New Mexico in 1988. an effort to increase income from oil reveHowever, the Paleozoic and Lower Creta- nues. The rise in oil production createdan
ceous sections of the PedregosaBasin are oversupply of oil and causedprices to plumpromising targets(Thompson,1980,1981). met. A gradual reduction of world petroleum
Nao Mexico Geolo3y November 1989
930
.9E
12O o,
E) zs
1 o o3
E€ 20
80
c
8t tu
'o
El'
56
Fb
-E
60 -:
*= ;z
'\-\--z
c
---^\-n
,aT--\
\number
of rotary rigs
A L
a<!
ox
Av
T
:_
zv
:
E
E' o
6z
;r=>o>:
E*"tS:=i
*o6tHE*
3oz6in
19 8 6
!=>o>;y
o:oc=:'o
t1
f"*=:5<3
ez
>
-c=>o>;-;
oGo
O-lL
i<*>:5<,H
1987
1988
6:H
o:d
-)uG
19 8 9
FIGURE 3-Monthly crude oil prices and number of active rotary rigs in New Mexico during 7986,7987,1988, and early 1989. Data from Oil and
Gas Journal (1986a,b; 1987a, b; 1988a,b; 1989a,b).
stocks, rising worldwide demand, and par- ploration targetsand have added new oil retially successfulattempts by OPEC nati,ons servesand production that have supplanted
to reinstate production ceilingscauseda sub- declining production and reserves of older
sequent gradual, albeit unsteady, price in- pools. These discoveries were made in the
crease.
Strawn, Cisco, and Wolfcamp carbonatesof
Becauseof the decreasein oil prices, many the Northwest shelf and DelawareBasin, the
marginal and stripper wells were shut in or B o n e S p r i n g F o r m a t i o n a n d D e l a w a r e
plugged. Their production may never be re- Mountain Group of the Delaware Basin, and
gained unless oil prices increasesufficiently the Dakotaand Gallup Sandstonesof the San
to justify the expense of re-opening such Juan Basin.
wells. Stripper wells are defined as wells that
Continued oil discoveriesin the Sanfuan
produce less than 10 bbls per day. Approxand PermianBasins,as well as positivesigns
imately 20Voof oil production in New Mexico and hydrocarbon shows encounteredby
is from stripper wells.
wildcat wells drilled in the frontier areas,will
Declining oil prices have also resulted in
encourage exploratory drilling and devela decreasein drilling and exploration activ- opment. However, the number of active roity, which is reflected in the rig count for the tary rigs in New Mexico is tied to the price
state (Fig. 3). Oil reservesfound and devel- of oil (Fig. 3). Gradual declines in future reoped during the "boom" drilling yearsof L980- servesand production will probablybe halted
1982reachedpeak developmentin 1983and only if oil pricesrise enough to increasesub1984.The drilling slump of 1983-1985and stantially the number of activerigs. Oil prices
the more seriousdecreasein drilling during must not only rise, but also stabilize if an
1,986,7987,
and 1988led to fewer exploratioi increaseof the rig count is to occur. Indeed,
and development wells being drilled than in
a decline in volatility of oil prices may affect
the boom years. As a consequenceof de- explorationand drilling as much as, or more
creaseddrilling fewer discoverieswere made than, an increasein prices alone. Until the
and existing reseryeswere not developed as rig count increases,exploratory discoveries
quickly as in the past. The inevitable result will not keep pace with production and rewas decreasedproduction.
serveswill decline,unlessa major discovery
The Department of Energy (Energy Inforis made by one of the few rigs currently drillmation Administration, 1988)indicated that
ing. However, exploration for, and development of, major oil accumulations are
Pfoved reservesin New Mexicoincreasedby
10 million bbls from 1986to L987,but onlv L profitable even at a low price of $10/bbl.
million bbls were added by new field discovThe decreasein gasproduction in 1988was
e,ries,and only 1 million bbls were added by
causedby a decreaseddemand for gas,rather
discoveries of new reservoirs in old field6; than a decreasedcapabilityto produce gas.
12 million bbls were added by extensionsof
Primary markets for New Mexico gas are in
existing fields. This 14 millioh bbb of addiCalifomia, and those marketscontinue to use
tions were not sufficient to replace the 69 and convert to alternateenergy sourcesinmillion bbls of crude oil which were procluding fuel oil, hydroelectric power, and imduced during 1987.The calculated10million
ported subsidizedCanadiangas.Competition
bbls increase of reserves was caused by re- from fuel oil will decreaseif the price of crude
vision of reservecalculationsin known fields. oil stays relatively high. The recently signed
These revisions resulted partially from infill
U.S.-CanadianFree Trade Agreement may
drilling programs. The increase did not re- causeincreasedcompetition from Canadian
sult from discovery of new hydrocarbons. gas.
However, oil discoveries made during the
Most of the gasproducedin 1987and 1988
last five to six years provide major new ex- was not replaced by new discoveriesof gas
November
1989
Naa Metico Geology
in conventionalreservoirs.The calculatedincrease in gas reserves during 1987 (Energy
Information Adminishation, L988)was caused
mostlv bv revision of calculationsof reserves
in known fields. rather than bv discoverv of
gas in new fields or by extensionof exisling
fields. Only L BCF were discovered in new
fields during 1987; L3 BCF were added by
discovery of new reservoirsin old fields; 1l{4
BCF were added by extension of existing
fields. Theseadditionswere not sufficientto
replace the 813 BCF which were produced
during 1987.However, the major reservesof
coal-bedmethane that were added during
1987and 1988do not appear in the reserve
estimates of the Department of Energy. If a
market for that coal gas can be found, then
the long-term outlook for gas production in
New Mexico is good.
AcrNowlrocMENrs-Prentiss Childs of the
New Mexico Oil Conservation Division provided the well completion statistics. Neil
Whitehead III provided informative discussion and information pertaining to coal-bed
methanein the San fuan Basin.Frank Kottlowski, Royfohnson, and SamThompsonIII
reviewed the manuscript. Lynne McNeil
typed the manuscript and Rebecca Titus
drafted the illustrations.
References
Broadhead,R. F., and King, W. E., 1988,Petroleumgeology of Pennsylvanian and Lower Permian strata, Tucumcari Basin, east-centralNew Mexico: New Mexico
Bureau of Mines and Mineral Resources,Bulletin 119,
75 PP
Cather, S. M., and Johnson,B. D., 1984,Eocenetectonics
and depositional setting of west-centralNew Mexico
and eastemArizona: New Mexico Bureauof Mines and
Mineral Resources,Circular 792,33 pp.
Energy Information Administration, 1988,U.S. crude oil,
natural gas, and natural gas liquids reserves,1987 annual report: U.S. Department of Energy,Energy Information Administration, 1987annual report, DOBEIA0216(87),105 pp.
Gorman, J. M., and Robeck, R. C., 1946,Ggology and
asphalt deposits of north<entral Guadalupe County,
New Mexico: U.S. GeologicalSuruey,Oil and Gas Investigations, Preliminary Map 44.
Kefley,V C., 1978,Gmlogy of EspaflolaBasin,New Mexico: New Mexico Bureau of Mines and Mineral Resources,Geologic Map 48, scale 1:125,000.
Kelso, B S, Wicks, D E, and Kuuskraa,V A, 1988.A
geologic assessmentof natural gas from coal seamsin
the Fruitland Formation, SanJuan Basin, topical report
(September1986-September1987.):
Gas ResearchInstitute, report GRI 8710341,
53 pp
Kottlowski, F E, and Stewart, W I, 1970,The WolfcampianJoyita uplift in central New Mexico:New Mexico Bureau of Mines and Mineral Resources,Memoir
23, pt I, pp. 1-31.
McKallip, C , Jr , 7987,New Mexico's Newkirk field: Oil
and GasJournal,v 85, no 27, pp 56-57
McKamey, K E , 1988,A symposium of the oil and gas
fields of southeasternNew Mexico: Roswell Geoloeical
Society,1988symposiumsupplement,336pp
Meyer, R. F, 1966,Geology of Pennsylvanianand Wolfcampian rocks in southeastNew Mexico: New Mexico
Bureau of Mines and Mineral Resources,Memoir 17,
123 pp.
Molenaar, C M , 7977, Stratigraphyand depositionalhistory of Upper Cretaceousrocks of the San Juan Basin
area, with a note on economicresources:New Mexico
GeologicalSociety,Guidebook to 28th field conference,
pp 159-166
Oil and GasJournal, 1986a,SelectedU S and world crude
prices: Oil and Gas Journal, v M, no 2, p 85; no 5,
p. 134; no 10, p 79; no 15, p 746;no 19, p. 90; no
23, p. 67; no 28, p 120;no 32, p 115;no 35, p 733;
no. 41, p 97; no 45, p. 124;no 49,p. 58
Oil and Gas Journal, 1986b,Hughes rig count: Oil and
Gas Journal, v 84, no 2, p 85; no 6, p 134; no. 10,
'1.5,
p 79; no
p. 146; no 19, p 90; no 23, p 67; no
28, p 720;no 32, p 115;no 35, p 133;no 41, p 97;
no. 45, p 124;no 49,p.68
Oil and Gasfournal,1987a,SelectedU S and world crude
prices: Oil and Gas Journal, v 85, no 2, p 83; no 6,
p 54; no 10, p 53;no 15, p 75;no 19,p 78;no 23,
p 77;no 28,p 99;no 32,p 85;no 37,p 83;no.41,
p 103;no. 45, p 98; no 49,p.92
Oil and Cas Journal, 1987b,Hughes rig count: Oil and
Gas Journal, v 85, no 2, p 83; no. 6, p 54; no. 10, p
53; no. 15, p 75; no 79, p 78; no 23, p 77; no 28, p
99; no 32, p 85; no 37, p.83; no 41, p. 103;no. 45,
p. 98; no 49, p 92
Oil and Gasfournal, 1988a,SelectedU S and world crude
prices: Oil and Gas Journal, v 86, no 2, p 84; no 5,
p 6 1 ; n o 1 1 , p 8 3 ; n o . 1 5 , p8 4 ; n o 1 9 , p 6 7 ; n o . 2 4 ,
p 62; no 28, p 125; no 32, p 83; no 37, p. 109;no
47,p 83;no 46,p 733;no.50,p 77
Oil and Gas fournal, 1988b,Hughes rig count: Oil and
GasJournal,v. 86, no. 2, p.84; no. 6, p. 67;no.'l'!, p.
83; no. 15, p. 84; no. 79, p. 67; no.24, p. 62; no.28, p.
725;no. 32, p. 83; no. 37, p. lW; no. 41, p. 83; no. 46,
p 133;no 50,p 77.
Oil and GasJournal, 1989a,SelectedU S and world crude
prices: Oil and Gas fournal, v 87, no 2, p 75; no 7,
p 60; no 77, p 77
Oil and Cas Journal, 1989b,Hughes rig count: Oil and
G" lournu| v. 87, no 2', p 75; no 7, p 50;no 77, p
Slaton,M, 1988,Arsenic taints PecosSlopegas:Southwest Oil World, v 36, no 9, p 6
Slaton, M , 1989,Ironing out arsenic-taintedwrinkle:
Southwest Oil World, v 37, no 1,1,,
pp 74, 17
Speer,W R.,7976,Oil and gas explorationin the Raton
Basin: New Mexico Geological Society, Guidebook to
27th field conference,pp 217-225
Thompson, S, III, 1980,PedregosaBasin'smain exploration targetis Pennsylvaniandolostone:Oil and Cas
J o u r n a l v, 7 8 , n o 4 2 , p p 2 0 2 , 2 0 7 , 2 1 , 0 , 2 1 5
Thompson, S, nI, 1981,Petroleumsourcerocks in exploration wells drilled to Paleozoicor Mesozoicunits,
Hidalgo and Grant Counties, New Mexico: New Mexico Energy Institute, Report EMD-2-66-j306, 120 pp.
Thompson,S., III, and Jacka
Pennsylvanian
, A. D., 798'1,
stratigraphy, pehography, and petroleum geology of
the Big Hatchet Peak section, Hidalgo County, New
Mexico: New Mexico Bureau of Mines and Mineral Resources,Circular176,725pp
Woodward,L A ,7987, Oil and gaspotentialof the Raton
Basin, New Mexico: New Mexico Geological Society,
Guidebook to 38th field conference,pp. 331-338.
Woodward,L. A., Callender,J. F, Seager,W. R., Chapin,
C. E., Gries, J. C., Shaffer,W. L., and Zilinski, R. E.,
1978,Tectonic map of Rio Grande rift region in New
Mexico,Chihuahua,and Texas;in Hawley,J. W. (compiler), Guidebook to Rio Grande rift in New Mexico
and Colorado: New Mexico Bureau of Mines and Mineral Resources,Circular 153, sheet 2.
n
statetaxeson
Summary
of NewMexico
production
as0l July1, 1989
natural
resource
Resources
NewMexico
Bureau
of Mines
andMineral
byJames
M. Barker,
compiled
CommodiW
Tax
Rate and base
Potash
Resource
Processor; Service*
Severance
0.50%of taxablevalue
0 725Voof taxablevalue
2.5% of taxablevalue
Molybdenum
Resource
Processor; Service*
Severance
0.333%of taxablevalue
0.757oof taxablevalue
0.7257oof taxablevalue
Other taxable resources
(except potash and
molybdenum)
Resource; Processor;
Service*
0.75%of taxablevalue
Copper
Severance
Service; Processor*
0.50%of taxablevalue
0.75Voof taxablevalue
Gold, silver
Severance
0.20%of taxablevalue
Lead, zinc, molybdenum,
manganese, thorium, rareearth, and other metals
Severance
0.1257oof. taxablevalue
Clay, gravel, gypsum, sand,
pumice/ and other
nonmetals
Severance
0.725%of taxablevalue
Coal: surface
underground
Severance
Severance
$1.17per short ton until July 1, 1993
$1.13per short ton until July 1, 1993
Uranium
Resource
Severance
0.75% oI taxable value
3 5% of 50% of sales price
Oil, carbon dioxide
Severance
3.75% of taxable value
Natural gas
Severance
$0.153 per 1,000 cu ft or 3.75Vool
taxable value, whichever rs
higher; except new wells (after
May l, 7987) at 3.75% only
Oil, gas, and carbon dioxide
School
Ad valorem
3.15% oI taxable value
Many rates (counties certify
annually on September 1 to
Taxation and Revenue
Department)
Oil, gas, geothermal energ,
carbon dioxide, coal, and
uranlum
Conservation
School
0.78% of taxable value
3.757a of taxable value
Gas and hydrocarbons
incidental to processing
Natural gas processor
0.457oof taxable value
*Subiect to
only one of these taxes at a time Data source: Taxation and Revenue DeDartment, PO Box 2308.
(5051827-2700\ For information about severance and resource taxes contact
Santa Fe, New Mexico 875M)308
Cindy Lovato (5051827-0812); for oil and gas taxes contact Michael Holden (505/827-0805)
All subscriptions expire with this issue. Renew your subscription by sending $6.00
in the renewal envelope that has been inserted in this issue.
Nao Mexico Ceology
November
1989
75