Distribution of arenites in the Fernie Formation in Northeastern British Columbia
Ed Janicki and Akindele Balogun
Petroleum Geoscience Section, BC Ministry of Natural Gas Development, Victoria, British Columbia, V9A 5N7
Recommended citation: Janicki E. and Balogun, A. 2015. Distribution of arenites in the Fernie Formation in northeastern British Columbia. In: Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development, pp. 28- 44. Abstract Although a unit of quartzose sandstone in the Fernie Formation (Jurassic) of northeastern British Columbia has produced hydrocarbons, a detailed investigation of this sandstone has not yet been published. Bounding beds have high organic content; therefore the presence of clean sandstone could enhance the Jurassic’s potential for unconventional development. A similar correlatable sandstone unit, which produces hydrocarbons in central and southern Alberta, is called Rock Creek Member. There it contains Middle Jurassic (Bajocian) fauna. The age (Upper Jurassic?), stratigraphic affinity, and tectonostratigraphic significance of the rocks in northeastern British Columbia remain unclear, however we refer to them simply as Fernie Sand. As observed in core, and described in drill cuttings, the Fernie Sand consists of light greyish brown, bioturbated, glauconitic sandstone and siltstone. Despite subtle differences in grain size relative to bounding units, the Fernie Sand can be recognized on well logs by a leftward shift of the gamma-ray curve. An isopach map of relatively clean sand based on more than 700 wells indicates that: 1) the Peace River arch was a paleotopographic low during Jurassic sedimentation; 2) Fernie Sand appears to define discontinuous lenses encased in finer grained rocks rather than continuous tabular bodies; 3) ovoid accumulations of Fernie Sand define a northwest-southeast oriented trend extending across the axis of the Peace River arch; and a smaller body is present near the depositional-erosional edge of the unit farther to the northwest.
Key Words: Jurassic, unconventional hydrocarbon development, Rock Creek, Fernie Sand, erosional edge, Bajocian. ______
1. Introduction unit1, we call Fernie Sand, similar in wireline log The Fernie Formation is found in the subsurface morphology and apparent stratigraphic position to the over a large area extending from southern Alberta into Rock Creek Member of Alberta. northeastern British Columbia (Figure 1). It is On its own, the Fernie Sand in NEBC could be constrained to the northeast by an erosional edge. adequately porous and permeable to produce Southwest of the Cordilleran deformation front it conventionally as it does at the wells shown in Figure 2, becomes dramatically deeper, and often greatly or as the Rock Creek Member does in Alberta. Even if thickened due to structural disruption. The study area uneconomic as a conventional producer it may enhance for this report concentrates on the area between the unconventional production due to its relatively Fernie erosional edge and the deformation front in favourable reservoir characteristics when compared northeastern British Columbia (NEBC). with the bounding organic rich shale units below (Poker Chip member) and above (Upper Fernie Member). The 1.1 Economic Significance possible economic advantage of having a thick section The Jurassic section in British Columbia has of Fernie Sand directs us to better document the attracted relatively little economic interest even though stratigraphic relationships and extent of the Fernie Sand its high organic content (e.g., Fowler et al., 2001; Ferri in the northeastern part of the province. Towards this et al., 2013) might make it an attractive target for purpose, gamma-ray well logs provide data for isopach unconventional development. In central Alberta, oil companies have produced hydrocarbons from the Rock 1 The British Columbia Oil and Gas Commission, which is Creek Member (Middle Jurassic) for several decades. In the regulatory body for oil and gas operations in the province, terms the productive interval in these wells “Rock Creek A”. NEBC, several wells (Figure 2) have produced gas or In this report we refer to this interval as Fernie Sand for condensate from relatively thick sections of a sand reasons explained herein.
28 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
N
Northwest Territories Yukon Territory
Fort Nelson
Alberta Alaska F ern ie Fort St. John E r o s io Grande Prairie n a l
E d C g o e British Columbia r di lle ra n
de fo rm a tio n fro nt
Vancouver
Victoria
Washington Idaho
080 160 320 Kilometers
Figure 1. Study area is within the red outline. Most of the study is focused on the area between the Cordilleran deformation front and the erosional limit of the Fernie Formation.
29 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
125 kilometres 57°37’N 94-G 94-H 120° W Fernie
Rock Creek ALBERTA b-036-C 094-A-13
C 94-B o r d i ll e Fo x r Cree a Ft St John k Esca n r pm d ent e f o r 13-32-078-14W6 m 05-33-078-14W6 a t i Dawson Ck o n
f r o 93-P 93-O n t
54°22’N 93-J 93-I 123°20’W
Figure 2. Three wells (b-36-C, 13-32 and 5-33) have produced gas or condensate from the Rock Creek Member (Fernie Sand) as designated by the British Columbia Oil and Gas Commission. Yellow dots symbolize wells with data used for this report. Fernie erosional edge is indicated; Rock Creek (Fernie Sand) can be either depositional or erosional.
30 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun maps; and stratigraphic cross sections provide estimates the Late Jurassic an eastward-migrating foredeep took of where relatively clean sandstones may be found, and the place of the stable shelf. therefore possibly enhance unconventional production. Upper Jurassic sediment is characterized as an eastward thinning, clastic orogenic wedge. During the 1.2 Nomenclature early part of the Late Jurassic an eastward-migrating Jurassic nomenclature was largely carried over foredeep took the place of the stable shelf. Subsidence from Alberta even though the tectonic and stratigraphic of the foredeep was caused by the collision of accreted setting differs. In NEBC the Fernie Sand is also oceanic allochthonous terranes. Thick sediment was commonly called by industry Rock Creek (Figure 3), deposited and largely preserved in the foredeep, while a though it is likely of a different age and facies than the regional sub Upper Jurassic unconformity marked the Rock Creek Member of central Alberta (Ford 2009, eastern edge. Poulton et al, 1990). In this paper we refer to the Jurassic sand unit of NEBC simply as Fernie Sand until 2.2 Stratigraphy its age and stratigraphic affinity become well The Fernie Formation is a succession of established through further paleontological dating, predominantly shales, siltstones, and sandstones with a detailed stratigraphic correlations and agreement type section in the foothills of British Columbia near among users on a new name. Fernie Sand is also the Fernie (Warren, 1934). Warren (1934) coined the term name currently used by the British Columbia Ministry Rock Creek Member for a thin (~ 3-10 metre) unit of of Natural Gas Development for the purposes of calcareous quartz arenites in the Fernie Formation, petroleum tenure. taking the name from a creek near Blairmore, Alberta Nomenclature is further confused by the common where the unit is well exposed. The unit is extensively use of several other names for the Fernie Sand. Aside developed in the subsurface of central and southern from the name Rock Creek, which is extant in the Alberta, where it contains Middle Jurassic (Bajocian) literature, industry wellfiles and regulatory bodies fauna (e.g., Marion, 1984; Losert, 1986; Poulton et al., (British Columbia Oil and Gas Commission, Alberta 1990, 1994), which would place it in the miogeoclinal Energy Regulator), the reader might also find the succession. A similar sandstone unit occurs in NEBC Fernie Sand in NEBC called: “Upper Fernie and northwestern Alberta, which Lackie (1958) Sandstones” (Poulton et al, 1990), “Niton” (Alberta correlated with the Rock Creek Member of central Geological Survey, 2015), “Green Beds” (e.g. Well File Alberta. However, Poulton et al. (1990, 1994) argued for ARCRES HZ PARKLAND A04-08-081-16), or that the northern sandstones are an entirely different perhaps other names. unit and were deposited above the sub-Upper Jurassic unconformity during the Upper Jurassic (Figure 3). 2. Geological Setting This conclusion was based on lithologic similarity of 2.1 Tectonic Setting the sandstones to beds in the upper part of the Fernie The Jurassic section in British Columbia and Formation, and observation of a sub-sandstone unit Alberta provides a record of profound transition in the unconformity in outcrop. tectonic evolution of the Canadian Cordillera. The early Poulton et al. (1994) restricted the use of 'Rock Jurassic is characterized by stable shelf shales and Creek Member' to demonstrably Middle Jurassic limestones that formed a west-facing miogeoclinal (Bajocian) sandstones in central and southern Alberta, prism extending over the western flank of North and combined those rocks north of about latitude 54° America (e.g., Miall et al., 2008). A significant hiatus 30' N with rocks of the Upper Jurassic (Oxfordian- intervened during the Middle Jurassic likely due to Kimmeridgian) Upper Fernie Formation, while uplift and erosion at the initiation of the Columbian acknowledging that Bajocian sandstones might also be orogeny (Poulton et al, 1990). During the early part of developed in the north. A palynological study by Ford
31 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
(2009), based on core from a well near Dawson Creek Poulton et al., 1990) indicate that it was a (13-32-078-14W6, Fig. 3), documented Oxfordian to paleotopographic low during the Jurassic. Kimmeridgian microplankton taxa in siltstones and As typically observed in core, the Fernie Sand consists fine-grained glauconitic sandstones through an interval of light greyish brown bioturbated, glauconitic of about 7 metres. The underlying approximate 10 sandstone and siltstone (Figs. 6, 7). The sandstones are metre-thick section of fine-grained glauconitic moderately well sorted, very fine-grained subarkoses sandstones yielded possible Middle Jurassic taxa, containing accessory glauconite, pyrite, and detrital although Ford (2009) considered this result carbonaceous material (Lackie, 1958). Clay partly inconclusive. So although palynology from one core occludes pore spaces. The fine grain sizes and points to an Upper Jurassic age for these sandstones, preservation of delicate stratification indicate the possibility remains that some sands are Middle deposition in a relatively low-energy environment. Jurassic. Additional palynology at more locations will Where the Fernie Sand is relatively thick and clean, be needed to establish the age or ages of the Fernie as at 7-1-80-15W6, porosity can exceed 10%, but Sand. generally averages 5 – 6%. Permeability reaches 0.1 millidarcies in places, though it is mostly much lower. 3. The Fernie Formation and Fernie Sand in The upper part of the Fernie Formation contains NEBC thin siltstone interlayers that are similar to the Fernie 3.1 Observations Sand. Because of only subtle differences in grain size About 28,000 wells intersect the Fernie Formation relative to bounding units, Fernie Sand is commonly in NEBC. Of these, we examined wireline logs from recognized on well logs by a slight leftward shift of the more than 700 (Figure 2) selected on the basis of gamma-ray curve (e.g., Fig. 8). It can only be geographic representation and availability of detailed confidently identified where sandstones are relatively lithological descriptions and gamma-ray curves. We clean and thick. Where the Fernie Sand is poorly used this data to examine the stratigraphic relationships developed, rocks of the Poker Chip Member cannot be of the Fernie Formation with emphasis on Fernie Sand. readily distinguished from overlying Upper Fernie Isopach maps, stratigraphic cross-sections, and a map Formation shales. Figure 9 illustrates where Fernie of relatively clean sandstone were drawn to show its Sand has been confidently identified from wireline distribution in relation to the bounding organic rich logs. Subcrop edges of Fernie Formation subunits, shales. Well logs also provided the control needed to based upon study wells, are also shown. Collectively, draw formational edges (e.g. Figures 3 and 4). the Jurassic units define a southwestward thickening 2 An isopach map for the entire Jurassic section (Fig. wedge beneath the Bluesky Formation (Figs. 10, 11). 5) indicates that, although irregular in detail (e.g., over Within its limited extent the Fernie Sand retains a Peace River arch) thinning generally trends relatively consistent thickness (10-20 m). West of northeastward across regional strike up to its erosional location 10-8-77-20W6M (WA 10263, Fig. 10), the edge. In general, Jurassic isopach thickens rapidly to Fernie Sand loses its lithologic character and gamma- the southwest into the foreland basin, and is more ray expression, and becomes indistinguishable from constant near the edge. The Peace River arch, where the argillaceous rocks of the Poker Chip and Upper Fernie Jurassic section is especially thick, is a long-lived Formation. Along section B-B' (Fig. 11), the Fernie structural feature with an early history (Neoproterozic Sand appears to define discontinuous lenses rather than to Paleozoic) as a positive topographic element and a a single tabular body. In longitudinal profile later history as a depression (O’Connell et al, 1990). Increased thicknesses along the axis of the Peace River 2 The Bluesky Formation of Lower Cretaceous age is arch (Fig. 5; also noted by O'Connell et al., 1990 and commonly used as a stratigraphic datum in the region based on its widespread occurrence and the assumption that its facies implies a near‐level environment of deposition. 32 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Stages NE British Columbia NW Alberta West-Central Alberta Albian Bluesky Ostracod Aptian Gething Gething Ellerslie Barremian Cadomin
s
u
r Hauterivian
o
e e ? ? c w Bickford
a p
o
t u
L
e Monach
Valanginian o r
r
G ?
C Beattie Peaks
s
e
n
i n
Berriasian s
n i Monteith s ?
a ?
M n
a Nikanassin k Tithonian i Transition Beds N ? Nikanassin
r ? e Upper Fernie Passage p Kimmeridgian
p Beds
U nd Upper Fernie ie Sa Fern Oxfordian Upper Fernie Niton ? ? ?
Callovian
n n n
o o o
i i i
t t
Bathonian t
a a c a
e
i
l
m m m
s
r r d r
s
o o o
d
i
F F a F
r
e e e
M
i i i
u
n n n
J
r r r
e e e
F F Bajocian Rock Creek ? F ? ? Rock Creek Aalenian Poker Chip Shale
Poker Chip Shale Poker Chip Toarcian ? Shale
? ?
r Lower Fernie Red Deer e Pliensbachian limestone and
w
o shale unit ?
L (’Nordegg’) ? ? ? ? Sinemurian Lower Fernie ? limestone and Nordegg shale unit ? ? Hettangian ? (’Nordegg’)
Figure 3. Stratigraphic correlation of Jurassic and Lower Cretaceous units in the Western Canada Sedimentary Basin (adapted from Poulton et al., 1994 and Tittemore, 1991). Although the Fernie Formation is often called “Fernie Group” (e.g. Frebold, 1957), it has not been sub-divided into formations (Glass, 1990). Fernie Sand is used here in place of Rock Creek, which is a name traditionally used by industry in British Columbia for sandstones in the Fernie Formation that are likely younger than the Rock Creek Member of west-central Alberta. Niton is the name adopted by the Alberta Energy Regulator for the Fernie Sand equivalent in northwestern Alberta. Rock Creek of Bajocian age might be present in northeastern British Columbia.
33 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
(Fig. 12) the Fernie Sand appears to maintain unto a topographically higher shelf. However, the continuity along strike before ultimately pinching out presence of thick clean Fernie Sand over the Peace to the northwest. Consistent with the general loss of River Arch also suggests the controlling influence of the Jurassic section, the loss of Fernie Sand to the topography on distribution (O’Connell, 1990). northeast is more due to erosion than non-deposition. Depressional lows, or lack thereof, could also be a The cross-sections across strike (Figures 10, 11) primary controlling factor as to where Fernie Sand strongly suggest erosion to the northeast as the was deposited and preserved. overall Jurassic section rises up from the foredeep
Figure 4. For cross-section A-A’ see Fig. 12, for B-B’ see Fig. 13 and Fig. 14 for C-C’. The location of the type well shown in Figure 8 is at 202/b-036-C 094-A-13/00.
34 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
57°39'N, 120°00'W
0 94-G 94-H
C
o
r d i l l e r a
n
d e
f o r m
a 0 t i o
n 25 f r o n
t
50
94-B 1 2 5 75 1 0 2 0 5
50
75
h rc 10 A 0 er 125 iv R ce ea P
93-P 125 Kilometers 94-O 0 30 60 90 55°21'N122°48'W
Figure 5. Isopach map of combined Jurassic units. Contour interval is 25 metres. During the Jurassic the Peace River arch appears to have been a northeast-trending depression that received sediment.
35 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
202/b-036-C 094-A-13/00
2006
21152
Fernie
Fernie Sand
Poker Chip
Nordegg
Figure 6. Rock Creek Member (Fernie Sand). Light grey bioturbated and burrowed siltstone. Note Triassic vertical burrow (1515 metres 4-14-79-14W6).
GR (GAPI) DT (US/M) 0.00 150.00 500.00 100.00
Figure 8. This Gamma Ray / Sonic log is a good example of Rock Creek (Fernie Sand) morphology, and one of the Rock Creek producers. Baseline gamma ray reading for Fernie shale is indicated by a red vertical line. The yellow line represents 30 API from baseline. Gamma Ray to the left of the yellow line was used to map Rock Creek clean sand. For location see Figure 4. BONAVISTA BLUEBERRY B-A036-C/094-A-13, Suspended Gas / Jurassic Rock Creek
Figure 7. Rock Creek (Fernie Sand) is the dark rock at the top of the photo. It is in an abrupt unconformable contact above a rubbly, lighter coloured (phosphatic?) layer in Poker Chip shale; 1513 m, 12-7-81-16W6. 36 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
125 kilometres 57°37’N Nordegg 120° W X 94-G 94-H Fernie ? X
X X X X Rock Cree XX XX XX X X X X k X X X X X X X X X X X X X X X X X X X X ??XX X ? X X X XXX X ? XX X X X XX ? X X X X X X ? X X X XX ?X ? ? X X XX X X ? ? ? XX XX X ? ? ? X X ? ? X X ? ? ? XX ? ? ? ??? ? ?? ? ? ? ???? ? ? 94-B X ? ? ?X ?X ? ? ? ? ?? ? F?o ? ? x C ? ? ree k E sc arp me ? nt
? ? ? ? ? ? ? ? ? ?? ?? ? 93-P ? 93-O ? ? ? ? ? ? ? ? ? ? ? ?? ?? ? ? ? C ? o ? ? rd il le ? ra n d e fo rm a t io n 93-I f 93-J ro 54°22’N n 123°20’W t
Figure 9. This map shows where Fernie Sand (Rock Creek Member) was confidently recognized on wireline logs. An “A” indicates where Fernie Sand may be present but poorly developed or difficult to recognize. An “X” indicates where it has been clearly eroded. Note that it has sometimes been eroded south of the erosional edge. Locations marked by “+” have easily recognizable Fernie Sand. A “?” indicates uncertainty. Nordegg and Fernie erosional edges are depicted in blue and brown respectively. Rock Creek edge, in orange, is limited by either erosion or non-deposition.
37 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Southwest Northeast A A’
200/c - 053 -B 093 - P - 11/00 <=14293.0m=>100/10 -08- 077 - 20W6/00 <=25771.9m=> 100/07 -08-079 -18W6/00 <=14991.1m=>100/12 -09-080 -17W6/00 <=18550.7m=> 100/07 -27- 081 - 16W6/00 <=24000.6m=> 100/11 -21-083 -14W6/00 <=25429.0m=> 100/02 -09-086 -14W6/00 +689 1980 +966 1997 +722 1979 +761 2009 +754 1968 +657 1996 +752 1997 05368 10263 04937 25280 02250 09917 10706 Bluesky 1000 Bluesky 1800 1100
1900 1100 1200
1300 Fernie 1100 1900 1200 Cadomin Nordegg 2000 1200 1300 Fernie ? Cadomin Triassic 1400 Cadomin Cadomin Cadomin Rock Creek Nikanassin Nikanassin Cadomin 1200 2000 1300 Nikanassin Nikanassin Nikanassin Nordegg 2100 1300 Fernie 1400 Triassic
1500
1300
2100 1400 Fernie 2200 1400 1500 Poker Chip Nordegg
1600
Fernie Triassic 1400 TD 1471.2m 2200 1500 GR (GAPI) Poker Chip 0.00 150.00 2300 1600 Nordegg
1700 Triassic Poker Chip 1500 2300 1600 Nordegg 2400 Fernie 1700 Triassic 1800
1600 2400 1700 2500 ? Fernie Poker Chip 1800 Nordegg
1900
Triassic 1700 2500 TD 1803.0m1800 GR (GAPI) 0.00 150.00 2600 1900
Nordegg 2000
Triassic 1800 2600 2700 2000
2100
1900 2700
Figure 10. Stratigraphic Cross-section A – A’. The Rock Creek (Fernie Sand) appears to be as thick close to the northeastern edge as anywhere else. Its limit could be either depositional or erosional. To the southwest it becomes difficult to pick out from the surrounding shales.
38 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Southwest Northeast B B’
11-34-081-24W6/00 <=20204.4m=> 100/06-09-083-22W6/00<=7416.3m=>100/11-19-083-21W6/00 <=10945.6m=> 100/13-22-084-21W6/00 <=28496.4m=> 100/06-23-086-19W6/00 <=28107.6m=> 100/06-08-088-16W6/00
1980 1964 1978 2006 1966 1992
05290 01443 04598 21379 01941 07857
Kfalher 500
Kfalher_b 900 Kfalher_c Kwilrich 600 400 700 900 600 1000 700 500 800 1000 Bluesky Bluesky 700 1100
800 Kdunlevy 600 Nordegg 900
Cadomin TRbaldnnl1100 Cadomin Cadomin 800 Cadomin Rock Creek Poker Chip 1200 Jnikanssn Nordegg 900
700 TRbaldnnl 1000
Cadomin Jnikanssn 1200
Jnikanssn 900 Fernie
Rock Creek 1300 1000 800 Fernie Jnikanssn Poker Chip 1100 Nordegg 1300 Poker Chip TRbaldnnl 1000
Fernie Nordegg TD 1345.0m TRbaldnnl GRS (GAPI)
1400 0.00 150.00
TD 1178.0m 1100 900 ? GRGM (GAPI) Rock Creek 0.00 150.00 Nordegg TRbaldnnl 1100 1500 1200 1000
Fernie 1200 1600 1300 1100 Rock Creek Poker Chip Nordegg
TRpardont 1300
TRbaldnnl 1700 1400 1200 1400 1800 1500 1300
TD 1855.6m GR (GAPI)
1500 0.00 150.00
Figure 11. Stratigraphic Cross-section B – B’ The Cadomin directly overlies the Rock Creek (Fernie Sand) near the northeastern edge here; much of the Jurassic is eroded; even the Cadomin is missing near the Rock Creek edge at 06-08-88-16W6M (WA 7857).
39 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Northwest Southeast C C’
100/06-26-087-23W6/00 <=24424.7m=> 100/06-30-085-21W6/00<=11731.3m=>100/13-22-084-21W6/00 <=27030.7m=> 100/09-21-082-19W6/00 <=30638.1m=> 100/12-09-080-17W6/00 <=23938.1m=> 100/06-10-079-15W6/00<=16340.6m=>100/06-13-078-14W6/00
1988 1977 2006 2012 2009 2007 1970
06754 04052 21379 28087 25280 22955 02801
1200 Bluesky Bluesky 1100 1200 1400 1300 900 900 Cadomin Cadomin Cadomin 1300
1200 Cadomin
Nikanassin 1300 Cadomin
Nikanassin 1500 Cadomin
1400 Nikanassin Fernie 1000 Cadomin Fernie 1000 Nikanassin
1400 Rock Creek Rock Creek Nikanassin
Nordegg 1300 Fernie Poker Chip
TRbaldnnl 1400
Nordegg Rock Creek 1600 Fernie TRbaldnnl Fernie 1500
Poker Chip 1100 1100 Fernie Nordegg fernie_ej TRbaldnnl
1500 Rock Creek
1400 Fernie Poker Chip 1500 Rock Creek 1700 TD 1178.0m Nordegg Rock Creek GRGM (GAPI) Nordegg
0.00 150.00 1600 TRbaldnnl1200 Poker Chip TRbaldnnl Rock Creek TD 1745.0m Nordegg GR (gapi) 1600 Poker Chip 0.00 150.00 TRbaldnnl 1500 TRinga 1600 Nordegg
TRbaldnnl 1700 1300
TRsiphon 1700 1600 1700 1800
1400 TRcecil
TD 1785.0m GRS (GAPI) 0.00 150.00 1700
Figure 12. Stratigraphic Cross-section C – C’. Along strike, at a distance from its edge, the Rock Creek (Fernie Sand) is present to a greater or lesser extent everywhere. Thickness of Jurassic units varies due to variable degrees of erosion or possibly gaps in time between deposition.
40 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
57°39'N, 120°00'W Nordegg
Fernie
R o 94-G c k 94-H C re e k
10 8 6 4 b-036-C 094-A-13 2
0
94-B 0
0
2 6 C o 2 r d 4 4 i l l 0 e 6 4 r 4 a 6 h n rc A d r e ve f 4 i o R r 8 e m c 1 12 1 4 6 ea 0 4 a P t 8 i 2 6 o 6 n 4
f r 2 o 13-32-078-14W6 n 94-O t 05-33-078-14W6
2 Kilometers 4 0 30 60 90 59°16'N, 123°24'W
Figure 13. Isopach of Rock Creek Member (Fernie Sand) Clean Sand. Clean sand is defined by Gamma-Ray 30 API or more from a shale baseline. Current Rock Creek producing wells are indicated by red lettering. Contour interval is 2 metres. The study area is outlined by the red dashed line. 41 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Relatively clean Fernie Sand, as defined by a 30 have created depressional repositories of relatively API gamma-ray deviation from a shale baseline (Fig. coarse materials. 8), appears to occur in two areas (Fig. 13). A group of 4. Summary ovoid accumulations define a northwest-southeast In central and southern Alberta quartzose oriented trend that extends across the axis of the Peace sandstones of the Rock Creek Member contain Middle River arch and likely continues into Alberta. Farther Jurassic (Bajocian) fauna and record the waning stages northwest, near the edge of the unit, is a smaller more of miogeoclinal sedimentation on the western flank of discrete accumulation. North America. However, the stratigraphic affinity of While Figure 13 represents the distribution of the Fernie Sand in NEBC remains unclear. It may have relatively clean sand, it does not show all clastic rock of been deposited above a regional sub-Upper Jurassic siltstone grain size or greater. As mentioned above, unconformity and record the onset of sedimentation in sands may be present, and may be as coarse as fine- an eastward-migrating foredeep. grained sandstone, but don’t meet the strict 30 API Sample descriptions and gamma-ray logs from criteria for appearing on the map. A gross sand isopach more than 700 wells indicate that in NEBC the Fernie map for the Fernie Sand might capture those sands not Sand forms discontinuous lenses bounded by finer- represented on Figure 13, but would pose the difficult grained rocks. Several areas of relatively clean question of where to pick upper and lower boundaries, sandstones define a northwest-southeast oriented trend particularly where the sand is poorly developed. In that extends across the axis of the Peace River arch (a summary, Figure 13 is a representation of the paleodepression during Jurassic sedimentation) and distribution of the best quality Fernie Sand, but not likely continues into Alberta. Another sand body is necessarily of all the sand that is present in the Upper close to the erosional-depositional edge of the Fernie Fernie. Sand to the northwest. Other less clean sand in the 3.2 Interpretation Fernie section, not captured by the mapping criteria Clear conclusions cannot be drawn about the used here, is also likely present in the study area. environment of deposition at this time, but the Acknowledgements uniformity and fineness of grain size, silty laminae We appreciate the thorough review of a first draft disrupted by bioturbation and vertical burrowing would of this paper by Lawrence Aspler of the British seem to preclude a high energy channel setting. These Columbia Ministry of Energy and Mines. Fil Ferri of characteristics coupled with the uneven distribution of the British Columbia Ministry of Natural Gas clean Fernie Sand in NEBC is consistent with ebb tidal Development added comments on how to improve the shoal deposition (as characterized by Hubbard et al., document. Terry Poulton of the Geological Survey of 2002, in Alberta, for the Cretaceous Bluesky Canada and John Miller of Arc Resources Ltd. Formation), where a complex of relatively distal shoal provided insight on the complex stratigraphy of the sand bodies are encased in marine shale and mud. In Jurassic section. Alberta, the observed lateral continuity of the Rock Creek Member (Losert, 1986) can be inferred to represent a more proximal shoal depositional facies References cited (flood tidal shoals or shoal bars). Alternatively, higher Alberta Geological Survey, 2015. Alberta Table of gradients running down the foredeep may have played Formations, Alberta Energy Regulator, URL: a role in concentrating somewhat coarser materials by
42 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development Janicki and Balogun
Ferri, F., Hayes, M. and Goodman, E. 2013: 2007- McLean, J.R. 1976. Cadomin Formation: eastern limit 2011 Core and cuttings analyses; British Columbia and depositional environment. Geological Survey of Ministry of Natural Gas Development, Petroleum Canada, Paper 76-1B, pp. 323-327. Geology Open File 2013-1. McLean, J.R. 1977. The Cadomin formation: Ford, J.H. 2009. Palynological analysis of 12 core stratigraphy, sedimentology, and tectonic implications. samples from ARC Dawson 4-4-79-14W6M Dawson, Bulletin of Canadian Petroleum Geology, Volume 25, British Columbia. In well-history report; ARCRES pp.792-827. DAWSON 04-04-079-14W6M; British Columbia Oil Miall, A.D., Catuneanu, O., Vakarelov, B.K., and Post, and Gas Commission, Well Report 25486 R., 2008. The Western Interior Basin. In: Sedimentary Fowler, M.G. and Snowdon, L.R. 2001. Rock- basins of the world, Chapter 9, Elsevier, pp. 329-362. Eval/TOC data for ten northern Alberta and British Mossop and I. Shetsen (comp.), Canadian Society of Columbia wells, Geological Survey of Canada, Open Petroleum Geologists and Alberta Research Council, File 4124. URL Frebold, H. 1957. The Jurassic Fernie Group in the
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ARCRES HZ PARKLAND: Well history report; ARCRES HZ PARKLAND A04-08-081-16; British Columbia Oil and Gas Commission, Well Report. 27358.
44 Oil and Gas Geoscience Reports 2015, British Columbia Ministry of Natural Gas Development