GM 28434 OIL AND GAS RESOURCES OF QUEBEC PERMIT 514 OIL AND GAS RESOURCES OF QUEBEC PERMIT 514.'
PREPARED FOR
DEVELOPMENT AIGLE D`OR
CALGARY, ALBERTA
T . H. CLARK GEOLOGIST
MONTREAL
APRIL 30, 1972
Ministère des Richesse:', Naturelles, Québec SERVICE 9E LA DOC:.ï;!lb:i"N IAl'WN TECHNIQUE
Date: No GM: ~.'> TABLE OF CONTENTS
GEOLOGY
INTRODUCTION 1 SETTING ROCK EXPOSURES 2 WELL LOGS 3
STRATIGRAPHY INTRODUCTION 5 POTSDAM SANDSTONE 6 BEEKMANTOWN GROUP 7 CHAZY GROUP 7 BLACK RIVER GROUP 8 TRENTON GROUP 8 UTICA SHALE 10 LORRAINE SHALE 11 IGNEOUS ROCKS 11
STRUCTURE REGIONAL SETTING 12 FAULTS 12 FOLDS 16 IGNEOUS ROCK BODY PROBLEM 16
HYDROCARBONS
KNOWN OCCURRENCES PETROLEUM 17 NATURAL GAS 17
POSSIBILITIES OF FINDING COMMERCIAL QUANTITIES STRATIGRAPHIC TRAPS 20 POROSITY AND PERMEABILITY 22 STRUCTURAL TRAPS 23
RECOMMENDATIONS APPENDICES
APPENDIX A ANALYSES OF LOCAL ROCKS 27
APPENDIX B ANALYSES OF LOCAL NATURAL GAS 30
APPENDIX C LOGS OF LOCAL WELLS 31
REF ERE N C E S
ILLUSTRATIONS To follow p.
Figure 1 Map showing location of PR 514 and of wells mentioned in this report. 4
2 Logs of 4 deep wells to show general stratigraphie succession. 6
3 Isopach map of the Potsdam sandstone. 6
4 Isopach map of Deschambault (Lower Trenton) Formation. 8
5 Logs of most of the Oil Selections wells. 14
6 Plan to determine stratigraphie position of most of the Oil Selections 5-33 wells. 14
7 Determination of probable fault pattern in area of Oil Selections 5-33 wells. 14
8 Total gravity map of the region surrounding the eastern end of PR 514. 15
on page Table 1 Gas wells in the Cabane Ronde area. 18
Maps in pocket. Outline of PR 514 is shown on all maps, as far as possible.
1. Geological map of PR 514 and immediately surrounding land showing geological boundaries, structural features, location of logged wells, etc.
2. Quebec Department of Natural Resources Map 1407. Geology of the St. Lawrence Lowlands of Quebec.
Canada Mines and Technical Surveys. National Topographic series.
3. Laurentides West. 31 H/13 West Edition Jan. 1971.
4. Laurentides East. 31 H/13 East Edition Jan. 1971.
5. Vercheres. 31 H/14 Edition Jan. 1971
Maps 3, 4 and 5 have the outline of PR 514 traced upon them. 1.
OIL AND GAS RESOURCES OF QUEBEC PERMIT 514
GEOLOGY
SETTING. Permit 514 .(referred to below as PR 514) lies en-
tirely within L'Assomption county. It extends from the town of L'Assomption
westward for 18 miles to parts of the boundary between L'Assomption and
Terrebonne counties. Topographically the area is almost completely flat
(See Maps 2, 3, 4), and ranges in elevation from 50 feet above sea level
in the eastern part to 200 feet in the northern and western parts. The
Achigan river traverses most of the area, entering it just below St. Lin
at an elevation of about 175 feet above sea level and joining L'Assomption
river near the town of that name at about 75 feet above sea level. The
latter river leaves the area of PR 514 only a few feet below that elevation.
Other streams, in particular St. Esprit and Mascouche rivers, flow for only
a few miles within the area's boundaries. None of these streams is
navigable to anything larger than a canoe or rowboat.
There is only one feature that could be called a hill. Three
miles south of Pont Mousseau there is an elliptical area nearly a mile
long and half as wide with a summit 50 feet above the surrounding flat plain, and consists of what is probably modified ground moraine. The southern
boundary of this area cuts across the central part of this hill.
Almost all of the area lies within the band of Trenton Limestone as shown on Quebec Department of Natural Resources Map 1407 (Map 2, in pocket). The extreme eastern tip, consisting of somewhat less than half a square mile, is shown on that map to be underlain by Utica and Lorraine shales, although the latter formations do not outcrop here. The drift cover 2. is thick, especially near L'Assomption where it is on the average 100 feet
in thickness.
The average size of farms here is about 90-100 acres although
there is a tendency to increase the size with governmental assistance.
Most farms are narrow, rarely more than 1000 feet frontage, and usually go
back to range boundaries about one mile from the road. Ordinarily the
distal one quarter or rarely one third of a prosperous farm is woodland,
used almost wholly for domestic wood supply. The pattern of cultivated
land versus woodland is well shown on the topographic map in the pocket to
this report. All farms have service roads capable of supporting farm
vehicles running the length of the farm; these roads are rarely fit for farm
use before May first. The chief products are both natural and industrial
milk mostly trucked out of the county; cheese factories are few. Mixed
crops include wheat, oats, barley, both feed and silage corn. Truck
farming is an increasing occupation. A fair proportion of most farms is
given over to pastures.
ROCK EXPOSURES. Outcrops, all of Trenton limestone (except a
small occurrence of Utica shale and of igneous rock at L'Epiphanie), are
restricted almost wholly to river banks, and occur at L'Epiphanie only.
1) Along Achigan river at St. Roch de l'Achigan (Laurentides East map, in
pocket), where good exposures of the Tetreauville Formation (Upper Trenton)
can be seen for a mile and a half along the river banks. 2) A part of a
continuous outcrop of Deschambault limestone (Lower Trenton) a mile southeast
of St. Lin (Laurentides East map, in pocket) where, at the village itself
(Laurentides West map, in pocket), Black River beds outcrop beneath the
highway bridge, and Lower Trenton limestone continues downstream for a 3. mile, just crossing the western limit of PR 514. 3) Good exposures of
Tetreauville limestone (Upper Trenton) along St. Esprit river at and for a couple of miles downstream from Lawrence (Laurentides East map,
in pocket). 4) Along Achigan river at L'Epiphanie (Vercheres map, in
pocket), where Tetreauville limestone is overlain by Utica shale, and in a nearby quarry a thick sill of basic rock occurs close to the contact.
5) Small outcrops of Tetreauville limestone 2 miles north of L'Epiphanie
on St. Esprit river.
To be sure, beyond the limits of this permit additional outcrops
are known at Ste. Anne des Plaines (Bruchési, on Laurentides West map, in
pocket), St. Esprit (Laurentides East map, in pocket), Mascouche Rapids
(ibid.), in fields between St. Alexis (ibid.) and St. Jacques (ibid.), and
fine exposures along the Ouareau, Rouge, St. Pierre, and Assomption rivers.
These are sufficient in quantity, position, and nature to allow a dis-
tributional geological map to be drawn covering the area of PR 514 and
surrounding territories.
WELL LOGS. In addition there is a body of information from logs
of wells within and near PR 514. The locations of these are shown on the
geological map accompanying this report, and the logs are given in a
following appendix. Their names are given below, preceded by the number
assigned to them by the Quebec Department of Natural Resources as recorded
in Publication S-75, Pts 1 and 2, and subsequent additional sheets. Wells
included in Part 1 (less than 500' in depth) have- their numbers ringed in
this present report. Others, included in Part 2 (more than 500' deep),
have plain numbers. 4.
46 L'Assomption Experimental Farm Well
58 Quonto-International No. 1 Mascouche
9OÀ Oil Selections 1 In the text the QDNR number 86 Oil Selections 2 is usually preceded by the symbol #. 9 L' Oil Selections 3
92, Oil Selections 4
87 Oil Selections 5 For ready reference they are shown in Figure 1. 88 Oil Selections 6
89 Oil Selections 7
90 Oil Selections 8
91 Oil Selections 9
92 Oil Selections 11
93 Oil Selections 18
94 Oil Selections 20
96 Oil Selections 22
97 Oil Selections 23
98 Oil Selections 24
99 Oil Selections 29
100 Oil Selections 30
101 Oil Selections 31
102 Oil Selections 32
103 Oil Selections 33
141 Quebec Natural Gas No. 1 l'Epiphanie
142 Quebec Natural Gas No. 2 l'Epiphanie
144 Louvicourt No. 5 l'Assomption
145 Louvicourt No. 7 l'Assomption
151 Louvicourt Metal No. 8 l'Assomption
193: Parent Well \ ~ ` ~' a ` ~~` St-Thomas ~ 1~~~ G' ~`j`~ io.Ou ~~r/ ~~ ~. ~„~1~~~ ^`~ , f . } ~z \ ; ~\ ., \ ` / ~ .StPa Î de l'Indd1 rie ~ ► 'Ni 4 40'a n
~~ St-Alexis
106 St-Ours 105
St-Lin
TRECOEUR
- ntoin rehires 1 1
ST-
H ÈRES
COURNOYER St-C ales ais-de-Sales 84 85
57 H E ST-CH ARLES A me I LG Ji Figure 1
Map of part of QDNR map 1555 to show location of PR 514, and
nt Yi of wells mentioned in the text (red - more than 500' deep; Hilaire-Est blue, less than 500' deep). The wells are identified by their
QDNR numbers.
Ruia.
MONTRE
Chem* e ~ - ~CaûgFnâw 5.
STRATIGRAPHY
INTRODUCTION. The supra-basement rocks recognized in PR 514
belong to the following groups. The approximate range of thickness for
each is given in feet.
Quaternary Glacial and post-glacial sands, etc.
Lower Cretaceous Monteregian intrusives
Thickness in feet minimum maximum
Lower Lorraine 200 200 Utica 300 400 Upper 400 - 500 Trenton Middle 150 - 300 Lower 70 - 100 Black River 50 - 75 Chazy 250 - 500 Beekmantown 500 - 800 Cambrian Potsdam 500 - 1000 Totals 2420 3875
Quonto International No. 1 Mascouche 3248' Oil Selections No. 6 (only 60' of Potsdam to bottom of hole) 2545'
Of the above units, in addition to the overburden and igneous
rocks, only the Lower, Middle and Upper Trenton and the Utica are exposed.
All, however, have been cut by drill holes, as is shown in the log of Oil
Selections No. 6. In general increases in thickness are in the direction
of the axis of the Chambly-Fortierville syncline, but two prominent ex-
ceptions are the Potsdam and Beekmantown units, both of which pinch out toward the northeast, and neither reaches the St. Maurice river (55 miles to the northeast).
Each of the sedimentary groups is described below. 6.
POTSDAM SANDSTONE. Exposures of this formation are unknown within the limits of PR 514, but are abundant in the western part of the
Laurentides map area, and its presence 2 miles northeast of Ste. Julienne is indicated, in what is probably glacial drift, by a great abundance of large (up to 15 feet thick) blocks of this sandstone associated with only a few and smaller blocks of Precambrian. In well logs (Figure 2) it is recorded in the Quonto-International Mascouche No. 1 well (#58), and the
Oil Selections No. 6 well (#88), as well as in the Louvicourt Metal No. 8 l'Assomption well (#151). It is reasonable to expect that it will be found at the base of the Paleozoic section in any well drilled within this area.
It is divided into two formations. The lower, known as the Covey Hill
Formation, is conglomeratic at its base with boulders up to a foot in thickness, though pebbles up to an inch thick are most generally seen. The bulk of this member is a sandstone composed largely of quartz and possesses an all pervading matrix which prevents any but a minimal porosity to exist.
The remainder, the Chateauguay Formation, is a nearly pure quartz sandstone, containing very little matrix, with a resulting porosity which has allowed it to act as an aquifer in certain regions west of PR 514. Isopach studies of the Lowland region show that this upper part of the Potsdam sandstone
(Theresa and Cairnside members of the Chateauguay Formation) should be
100 feet thick in the northwestern part of the area increasing to 600 feet in the southeastern parts (Figure 3). Data are not abundant enough to allow the construction of an isopach map of the lower part of the Potsdam (Covey
Hill Formation), but it might range from a few hundred in the northwest to possibly one thousand feet in the southeast part of PR 514. In any probing for hydrocarbons the upper two or three hundred feet of Potsdam sandstone should be carefully scrutinized, and drilling should be carried down to Figure 2
QDNR QDNR QDNR QDNR 58 88 103 31 Surface --- Overburden
he scouc - 500' 1 Ma Upper ~re1?t°n al No. ion I 1000' t terna -In
to -- 1500' uon Q
--- 2000'
Upper Por sd Qm
LOwer Potsdam 2500' 2655'
3000'
Precambrian 3531' 3500' Logs of four deep wells to show the general stratigraphic succession. Horizontal scale 1" : 1 mile Figure 3
ST. LAWRENCE LOWLANDS OP QUEBEC
ISOBACMS OP TIM TIMRESA MEMBER
OF TIM CHATEAUGUAY FORMATION
IN FEET 0 ,o 2P
SCAIrE IN MILES
ST. LAWRENCE LOWLAOS OP QUEBEC
1St:WACHS OF TIM CAIRNSIDE MENDER
OF THE CHATEAUGUAY FORMATION
IN FEET
0 10 20
SCALE IN MILES 7.
the Precambrian basement so that any possible "granite wash" can be tested.
BEEKMANTOWN GROUP: (BEAUHARNOIS DOLOMITE FORMATION). This is a
light to medium gray rock nearly devoid of fossils, dense to crystalline
texture relieved in some beds by an abundance of vugs up to a few inches
across, filled partially or completely with carbonates. Some of these vugs
contain smears or complete layers of albertite or similar hydrocarbon
derivative. The vugs never produce an intercavity porosity and the dolomite
cannot be regarded with favor as a container of oil or gas. The rock could,
however, act as a roof-trap if appropriate porous structures in the under-
lying Potsdam Sandstone should exist. In thickness it probably ranges between
800 feet in the west to 500 feet in the east (Louvicourt Metal No. 8
l'Assomption (#151), 531 feet) .
CRAZY GROUP: LAVAL LIMESTONE FORMATION AND JOLIETTE MEMBER. Rocks
of this group do not outcrop in PR 514, but are known within a few miles of
Ste. Julienne (Laurentides East map, in pocket). No contacts with the
Beauharnois dolomite are known. At the base is a pure quartz sandstone
(the Joliette Member), well shown in drainage ditches near St. Alexis
Station, and a few miles further east in the bed of Assomption river at
Joliette (See Map 1407 in pocket). The percentage of quartz grains, for
the most part rounded and frosted, in this member ranges from 50 to 99%.
No sharp boundary has been recognized between the Joliette sandstone and
the overlying Laval rocks. It probably nowhere exceeds 50 feet in
thickness. The main part of the Laval Formation consists largely of fairly
coarsely crystalline limestone usually weathering buff in patches,
probably in response to high magnesia content. Fine-grained and very 8. coarse-grained types occur sparingly. Fossils are common throughout. At
Ste. Anne des Plaines it contains a small coral and bryozoan reef of the barrier type, but no indications of petroleum within it or in its flanking beds are known. It ranges in thickness from 250 feet to 500 feet, with a regional thinning toward the northeast although such thinning cannot be demonstrated within PR 514. The abundance of buff and brown weathering patches and beds indicates an incomplete dolomitization of the rock. This may have led to a porosity not apparent in surface outcrops but which might be of importance in depth. Especially is the porous and pervious Joliette sandstone of interest in providing a potential, though limited in volume, hydrocarbon reservoir.
BLACK RIVER GROUP: PAMELIA DOLOMITE, LOWVILLE LIMESTONE AND
LERAY LIMESTONE FORMATIONS. These formations, rarely more than 75 feet in aggregate thickness, are of little importance stratigraphically or economically. They are nowhere known to contain or to yield hydrocarbons.
TRENTON GROUP: DESCHAMBAULT, MONTREAL AND TETREAUVILLE LIMESTONE
FORMATIONS.
The Deschambault Limestone (Lower Trenton) is pretty regularly 70 to 100 feet thick here (Figure 4). It is a crystallized bio-fragmental rock made up in large part of crinoid plates and columnals worn and rounded by current action before final deposition. Recognizable fossils are common in certain beds. One of the most important features of this rock is the tendency toward vugginess. This occurs usually in coarse-grained beds up to 30 inches thick. Here and there residual hydrocarbon material lines the cavities. Of more importance is the fact that, save for the Tetreauville 90 100 o \ ~' ~~„~`--~..•-~.-.~-.~ ~ ~- ~00 _. , ~ \
' ~~
1 ~ ..• •
,/ • Montreal
• LEGEND
Isopuch contour • interval 10 feet
• • • • 1• 11 11 50 fet t 0 5 10 15 20 25 Scale in Miles Area of PR 514 shown in red.
FIGI:i;E 4• ISOPACH MAP of the DESCHAMBAULT Ii•N (After Young, 1964) 9.
Formation, this is the only formation known actually to contain liquid petroleum. At many localities, especially at St. Marc des Carrières
(40 miles southwest of Quebec City), where it is quarried, small drops of petroleum are liberated on a freshly broken surface, spreading out over an area of several square inches. A few drops of petroleum and a fair amount of albertite-like material were found in a vein in a core taken from this rock in the Neuville district. In the Louvicourt Metal No. 8
l'Assomption well (#151) petroleum was found yielding 3 to 4 gallons per day and lasting for a couple of days. Everywhere this rock has a strong odor
of petroleum when freshly broken open. At the Beaudry quarry, Joliette, a vein of albertite six inches across was reported during the early development
of the quarry, but of which no trace remains. This rock is therefore of
great interest as a source rock, and under favorable porosity and structural
conditions could yield satisfactory amounts of oil.
The Montreal Formation (Middle Trenton) consists of various types
of dark gray limestone, dense to fine-grained crystalline, thin to thick
bedded with partings and interbeds of shale up to several inches thick.
There is little regularity in bedding. No odor of petroleum has been
noticed in this rock nor is there any intergranularity favorable to hydro-
carbon storage. Rarely is there any dolomitization, and cavities are
restricted to the interiors of fossil shells which, however, never contain
residual hydrocarbons. It is therefore of little interest as either a
source rock or a reservoir rock. In thickness it ranges from 150 to 300
feet thick.
The Tetreauville Limestone (Upper Trenton), 400 to 500 feet thick,
consists largely of a dark bluish gray, dense, argillaceous limestone in 10. beds up to 6 inches alternating with beds of shale generally about one inch thick. Bedding is pronounced and even, allowing this rock to be dis- tinguished from other Trenton formations some distance away. Very rarely are there interbeds, up to 6 inches, or crystalline organic detritus.
Here and there both geographically and stratigraphically there are develop- ments of several tens, or even scores, of feet of limestone devoid of
obvious stratification. This is what was earlier called the Terrebonne
Formation, later degraded to Member status and now considered to be merely a facies development of the typical Tetreauville. The fauna of the latter
is large in number of species, but sparse in actual occurrence. Very little
difference can be found between the faunas of the original Tetreauville and
the Terrebonne rocks. It is supposed that the Tetreauville was deposited
in a quiet environment in which continued absence of muddy detritus allowed
carbonate deposition to take place, interrupted fairly regularly by con-
tributions of mud resulting in the shale partings and interbeds. The
Terrebonne facies on the other hand was probably the result of local and
temporary conditions of turbulence, destroying most or all traces of
regular bedding. Most of the Tetreauville limestone when freshly broken
open gives off a petroleum odor, and in a few places, notably along the
north shore of Ile Jésus, droplets of liquid petroleum issue from small
( < 1/4") cavities. This formation therefore must be considered a potential
source rock, though nowhere does it possess adequate permeability or
porosity to qualify it as a reservoir rock.
THE UTICA SHALE. This consists wholly of dark gray to black
shale with a brownish streak, and gives off an odor of petroleum when
freshly broken. This last feature is more characteristic of the thicker
bedded dark gray part of the formation than of the thinner bedded black
f 11. shales. It is known to outcrop only at L'Epiphanie. Throughout, the rock is dense with no interbeds that might provide porosity and permeability.
Like the Tetreauville it must be considered a potential source rock but in itself could not function as a reservoir rock. In thickness it ranges from 300 to 400 feet.
THE LORRAINE SHALE. That part of this formation underlying the southeastern tip of PR 514 is a dark gray shale and siltstone, never black, and never with a petroleum odor. It is very thin-bedded, rarely very fossiliferous. Probably no more than 200 feet occur here, although where the complete section is known it is about 2,400 feet thick.
IGNEOUS ROCKS. Currently being quarried at L'Epiphanie, just
southwest of the village, is a basic sill, about 25 feet thick, and lying almost exactly along the Trenton-Utica contact in Achigan river a quarter
of a mile to the east. In L'Assomption Experimental Farm well (#46) igneous
rocks, presumably sills, occur within the lower Lorraine and upper Utica formations (50 feet in the former, 40 feet in the latter). In the Parent
well (# 93 ) an improbable thickness of 120 feet of igneous rock was logged
low down in the Trenton limestone. Neither in Louvicourt Metal No. 8
l'Assomption well (#151) log nor in the logs of any of the Oil Selections
wells is there mention of igneous rock. In Quebec Natural Gas No. 2
l'Epiphanie well (#142) igneous rock occurs between the basal Utica and
the overburden. It is likely that all these occurrences are related, and
if so then the sill staggers from one stratigraphie horizon to another and,
were its distribution underground better known, it might reveal itself as a
potential trap, holding hydrocarbons beneath it. 12.
STRUCTURE
REGIONAL SETTING. This area lies within the St. Lawrence Lowland
of Quebec (See Q.D.N.R. Map no. 1407, in pocket), and close to its western
border. The Lowland is floored by Upper Cambrian and Ordovician sedi-
mentary rocks which have been deformed into the elongated Chambly-
Fortierville syncline the axis of which is consistently east of the St.
Lawrence River until it crosses the latter close to Quebec City. The western
limb of the syncline, on which PR 514 is situated, is relatively simple in
structure and consists of beds dipping pretty uniformly toward the south-
east at angles of from 0 to 10°, regionally about 2°, affected here and
there with small irregularities of little regional significance. The
eastern limb, with which we are not here concerned, is characterized by a
complex structure including folds, isoclinal and overturned, thrusts, slices,
and autochthon-allochthon relationship and complications.
FAULTS. Northwest of the Lowland lies the vast area of Grenville
rocks of the Canadian Shield. The contact has been seen in but a few
localities, but enough is known to deduce that in places the Shield-Lowland
boundary is a normal stratigraphic overlap phenomenon, in others it is a fault contact. In fact, there is a series of en echelon faults (See
Q.D.N.R. Map 1407) helping to form this boundary, striking about N20°E to
N40°E; and with the downdrop, up to 1500 feet, always on the southeast side, thus making the Lowland a semi-graben. The northwestern part of this area lies a few miles from the trace of one of these faults, here named the Ste.
Julienne fault. Possibly the southwestern continuation of another of these en echelon faults, the Chicot fault, cuts across the eastern tip of the area.
No faults are actually exposed here, but their presence is 13. guaranteed by relationships in neighboring map-areas. Just northwest of
PR 514 the Ordovician rocks are in fault contact with Precambrian,
Beekmantown, and Chazy rocks along the Ste. Julienne fault. This strikes about N25"E, and the Ordovician rocks to the northwest strike N40°E to
N70"E and abut against the fault so that they are successively eliminated in stratigraphic order from north to south. Near Bissonnet the movement is of the order of 1000 feet, whereas a mile or so west of St. Lin, where
Chazy rocks are brought to lie against Chazy rocks, the movement is minimal.
On Q.D.N.R. Map 1407 the St. Jacques fault is shown as possibly continuing from the vicinity of St. Jacques southeastward to the northern boundary of this area. Whether or not this continuation can be justified, there is no evidence supporting the view that the St. Jacques fault actually occurs within the area of PR 514.
A second fault passing close to L'Epiphanie should also be eliminated. Since its proposal, and appearance on Q.D.N.R. Map 1407, the opening of a large quarry south of L'Epiphanie has shown that the Trenton-
Utica boundary is unbroken across the line of the supposed fault. Other details concerning this "fault" are given under Igneous Rocks (p. 11) and also below (p. 16).
Since the geological mapping of the Laurentides East and the
Derchères West areas were completed numerous wells have been put down within and adjacent to PR 514. Save for those drilled just outside and to the northeast of PR 514, at L'Assomption, none contributes to the identification and location of faults. Referring to Figure 2, in which the logs of four deep wells are given, there is a suggestion of some anomalous situation 14. between wells #103 and #31, but from such evidence it would be hazardous to postulate either a fault or a flexure there. Figure 5 gives the logs of most of the Oil Selections Wells. The logs of Oil Selections Nos. 1-4 are too short to indicate anything more than a southeasterly dip. The same appears to be true for Oil Selections Nos. 5-8 although there is there a record of a more flattened dip between Oil Selections Nos. 7 and
8 than between Oil Selections Nos. 5, 6, and 7. The larger group of wells, however, is more definite, and assuming a normally uniform dip toward the southeast it is obvious that Oil Selections Nos. 29 and 33 are out of step with the remainder. The locations of these wells were, for the purpose of drawing these diagrams, taken from Q.D.N.R. Map 1555. In order to arrive at more reliable conclusions, I plotted the location as given by the Q.D.N.R. in a mimeographed "WELL LIST WITH COORDINATES", of both the Oil Selections
Nos. 5-8 group and the Oil Selections Nos. 9-33 group as shown in Figures 6 and 7.
Taking the latter group first the positions of the wells were pro- jected along regional strike lines (Figure 6), upon an arbitrarily chosen base line perpendicular thereto. The intersections were then used to imply the stratigraphic order of the wells, and a correlation chart was drawn up using the top and bottom of the Utica Formation with results shown in Figure 7.
There, it is apparent that the normal down-dip inclination (i.e. toward the SE), which should be a reasonably smooth line, is broken in at least four places. The two northwestern breaks between Oil Selections Nos. 30 and 31, and Oil Selections Nos. 31 and 22, show displacements too great to be attributed to warping, and consequently faults are introduced there.
Between Oil Selections Nos. 24 and 18 the vertical drop of the top of the
Utica is 250 feet, necessitating a fault between those two wells. Similarly,
Figure 5
87 88 89 90 100 99 101 91 1U2 97 103 8 c"12rACT. OT.L_L.,41,L1
6 2;0'
P,0' I OvvrbnrJen :I.:di.. Lorraine
Lew,r Lorraine
rticm Trrnt.m
6,3, M Trenton L Tr.ntcn 8 :lack River R.cerd
— 100'
Fan-p nr Forlt WELLS - camp 07 7.n14 VELLS - GRO”P OF 7 WELLS • !tit FF.V.1:11.•S 1. 2. 3. 4. CIL SE1.ECT/,N3 ,. A. 7. 8, OIL SELZCIIONS H'Af:FD APPF,'XIMATELY SFAMD Aprvoxlmitv 30, 29. 31. 9, 32, 23. 33 ONE MILE APART ALONE IRREILIARLY SPACED BUT A W-!T LILE. A NV-SE LINE. ARRAt.GFID AS :F TI'EY OCCIltRED AL!:1 A '7-SE DISTAWE FEFWEEM F30 P01:1 933 - 1 MILE.
'Figure 5. Logs of most of the Oil Selections Wells. Figure 6
Map of an area northeast of L'Assomption to show locations of Oil Selections wells Nos. 5-33, based on "WELL LIST WITH COORDINATES" issued by the Quebec Department of Natural Resources.
45°54' 30
31 A
45°531 29 933 22 4 23 24 2020ç,0 9 18 11 45°52' Each well position is projected along a line parallel to the regional strike upon lines AB and CD which are normal to the regional strike. The information gained is transferred to Figure 6 for structural interpretation. C - 45°51' N /1 5 `
One mile 6 0 SCALE 45°50'
D
45'49' Figure_ 7
~ arnO MoN Nt CO M W.N.W. MN NN N N ~ r, E.S.E. A r-1 n 300' Utica Shale in Oil Selections wells N.E. of L'Assomption, see . line A-B, Figure 5. Oil Selections 400' .. ~~ well.numbers are given along top ti margin. Broken lines: E.S.E. dip of 1.5". 500' Black vertical lines: Utica 0 shale in core. Red lines: deduced fauls, assumed to be 600' vertical and to be striking . parallel toedding. Well num- .bers taken fiom Quebec Depart- 700' . .. ment of Natural Resources . . Publication S-75.
800' J
. 900'
l one milei 1 \ 1000' Horizontal Scale
~ CO 200'
300'- Oil Selections well numbers are . given along upper margin. N. 400'-
500'-
600
.fs 700'- ~ . ~ .
800'- ~ J Utica Shale in it Selections Wells 5, 6, 7, near L'Assomption, 9 00'- along line C-D, Figure 5. Legend, Scale, Orientat on, etc. as above . A structural in erpretation based 1000'— in part upon th upper diagram. 15. if the normal dip line be drawn southeastward from Oil Selections No. 18 and norwestward from Oil Selections No. 33 there is a discordance of more than 100 feet and a fourth fault is introduced there. Between Oil
Selections Nos. 33 and 11 there may or may not be any faults, although the line connecting the tops of the Utica is not altogether in harmony with the regional dip, and with that connecting Oil Selections Nos. 22,
29, 20, 23, 9, and 24. Assuming that these faults are approximately parallel with the regional en echelon faults (e.g. Ste. Julienne) the pattern of faults appears as in Fig. 7.
This determination receives remarkable confirmation from the gravity map of the region (Figure 8) where the isogals show a strong deflection from a northwest-southeast trend to north-northeast--south- southwest direction.
A similar treatment of Oil Selections Nos. 5, 6, 7, and 8 shows discordances explicable only by faulting between Oil Selections Nos. 5 and
6, and between Oil Selections Nos. 6 and 7.
The gross result shows that, heading toward and doubtless crossing the northeast boundary of PR 514, there is a zone of NE-SW striking faults.
Between the stratigraphic horizons of Oil Selections No. 9 and No. 30
(see figures 6, 7) practically all of the Oil Selections gas showings, together with the oil show in Louvicourt Metal No. 8 l'Assomption (#151), are located.
None of these faults is exposed at the surface, nor has any been cut by the drill, consequently nothing is known of their nature in detail - whether they are clean cut surfaces, zones of fractures, brecciated zones,
100 Figure 8 '.3.
••.•1TK ••C141 0• •••[ •-•
/ •
Approximate limit of PR 514 -e- .to i. /. .r I : '4rw i . •/ I• • " 31 l3. /!, ÿ •2y S' l3 ..to‘ y~ei PLAN MAP 0. TOTAL GRAVITY SURVEY IN L'ASSOMPTION CO. 0 1 QUERE
Scale in Miles
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