Petroleum Source Rock Analysis of the Upper Devonian Torquay Formation of South Eastern Saskatchewan

A Thesis Submitted to the Department of Geology In Partial Fulfillment of the Requirements For the Degree of Bachelor of Science in Geology

Nathan T. Wielgoz

April 2014

i

Abstract

This study examines the geochemical characteristics of the Three Forks Group Torquay

Formation and presents a preliminary assessment of its source rock potential in Southern

Saskatchewan using an analytical approach that incorporates the high resolution sampling of

core, Rock-Eval VI pyrolysis and organic petrography.

This study shows that although two, relatively thin, organic rich zones exist in the Torquay

Formation (within southern Saskatchewan), they are considered as having marginal source

potential due to their low level of thermal maturity and generally low amount of organic

carbon. Generally values for total organic carbon are below 0.5 wt. %, only exceeding 1.0 wt. %

between 1015.5m to 1016.5m and associated hydrogen index below 250. Rock-Eval VI analyses

also indicates that most of the organic matter within the Torquay Formation is Type II to III,

with some IV, although petrographic analysis indicates the absence of terrestrial material,

strongly suggesting either the presence of reworked organic material or the alteration of

organic matter by insipient oxidation. This preliminary analytical examination suggests that the

Torquay Formation has limited source potential within southern Saskatchewan.

ii

Acknowledgements

Nathan Wielgoz would like to thank Professor Stephen Bend for all of his instruction and help in

completing this thesis and the subsequent research as well as advancing knowledge in the field

of Petroleum Geochemistry. Thanks must also go to Titilade Aderoju, for her assistance and

guidance in operating the RockEval 6 Pyrolyzer, and Oluseyi Olajide, for assistance in use of

various geological software such as Geoscout, Geovista, and Schlumberger Petrel. Support was

provided by the Saskatchewan Ministry of the Economy and Petroleum Technology Research

Centre.

iii

Table of Contents

Abstract…………………………………………………………………………………………………………………….………………………..…i

Acknowledgments………………………………………………………………………………………………………………………………..ii

Contents………………………………………………………………………………………………………………………………………..…….iii

List of Figures……………………………………………………………………………………………………………..………………………..v

1. Introduction………………………………………………………………………………………………………………………………………1

1.1 Foreword………………………………………………………………………………………………………………..………….1

1.2 Background……………………………………..……………………………………………………………………………..….1

1.3 Study Purpose……………………………………….………………………………………………………………………..….2

1.3.1 Goals………………………………………..…………………………………………………………………..…….2

1.3.2 Objectives…………………………………………………………………………………………………….…….2

1.4 Previous Studies…………………………………………………………………………..…………………………………….3

1.5 Stratigraphic Setting ………….……………………………………………………………………………………………….4

1.6 Study Area …………………………………..………………………………………………………………………………….….5

2. Methods..…………………………………………………………………….………………………………………………………………..….7

2.1 Core analysis…………………………………………………………………………………………………………..….………7

2.2 Rock-Eval Pyrolysis…………………………………………………………………………………………………….….…..8

2.3 Microscopy/Petrography…………………………………..………………………………………………………….….11

3. Results and Discussion…………………………………………………………………………………………….……………………...13

3.1 Lithological Characterization……………………………………………………………….………………….………..13

iv

3.2 Assessment of Rock-Eval Parameters……………………….…………………………………………….……......16

3.3 Petrographic Analysis……………………….……………………………………………………………………………....22

3.4 Kerogen Analysis……………………….…………………………………………………………………………….………..24

3.5 Geochemical Subdivisions of the Torquay Formation……………………………………….………….......25

3.6 Production Index and the Relation to Source Potential……………………….……………………..…....28

3.7 Comparative Analytical Approach (The Assessment of Two Methodologies)……….….….…...29

3.7.1 The Assessment of Source Potential in Microhorizons Versus the Conventional and

Widely Used Bulk-Rock Approach……………………….……………………………………………….…...29

3.7.2 Implication of the use of geochemical data to subdivide units……………...….….....30

4. Conclusions……………………….…………………………………………………………………………………………………….….…..31

5. Future Work …………………………………………………………………………………………………………………….………………31

References Cited……………………….…………………………………………………………………………………………….………….33

Appendicies…………………………………………………………………………………………………………………………..………………35

Appendix I……………………….………………………………………………………………………………….………………….36

Appendix II……………………….………………………………………………………………………………….………….……..38

Appendix III……………………………………………………………………………………….…………………………………...39

Appendix IV…………………………………………………………………………………………………………….……………….41

v

List of Figures

Figure 1: Previous subdivisions made to the Torquay Formation, p.4

Figure 2: Stratigraphic chart of southeast Saskatchewan, p.5

Figure 3: Isopach map of the Torquay Formation within Saskatchewan, p.6

Figure 4: Whole rock sample of Torquay Formation displaying extraction technique, p.7

Figure 5: Vinci Laboratories Rock-Eval Pyrolyzer, p.9

Figure 6: Schematic pyrogram for Rock-Eval pyrolysis, p. 10

Figure 7: Pyrolysis flow chart and derived/calculated parameters, p.11

Figure 8: Lietz Orthoplan microscope (UV/Fluorescence), p. 12

Figure 9: Leica M420 microscope (Macro), p.12

Figure 10: Whole rock sample form well 13-19-9-30W1, p.14

Figure 11: TOC chart for well 13-19-9-30W1, p.16

Figure 12: Geochemical log for well 13-19-9-30W1, p.17

Figure 13: Localized geochemical log for well 13-19-9-30W1, p.18

Figure 14: Migration Index Chart for well 13-19-9-30W1, p.19

Figure 15: Hydrocarbon Type Index chart for well 13-19-9-30W1, p.20

Figure 16: Genetic Potential chart for well 13-19-9-30W1, p.21

Figure 17: Petrographic analysis (UV/Fluorescence), p.22

Figure 18: Petrographic analysis (UV/Fluorescence), p.23

Figure 19: HI/OI Kerogen Type plot, p.24

vi

Figure 20: Suggested geochemical subdivisions for Unit 4 in the Torquay Formation, p.26

Figure 21: Production Index chart for the upper Torquay at well 13-19-930W1, p. 28

1

1. Introduction

1.1 Foreword

A petroleum source rock is defined as any rock that is capable of generating and expelling

sufficient hydrocarbon that ultimately forms an economic accumulation of petroleum (Hunt,

1996). The source rock is only one component of a given petroleum system which is the sum of

all components that are necessary to generate and retain petroleum within the subsurface.

Such components include the source rock, the process of petroleum generation, a migration

pathway, reservoir rock, trap, and seal (Bend, 2007). Since the presence of a viable source rock

is a fundamental component of any petroleum system an assessment of all potential source

rocks must be conducted when seeking to assess and determine the viability of any given

petroleum system. To determine the source potential of identified formational units, the

development of a number of analytical techniques and protocols through various case studies

was done. This resulted in the establishment of key methods, characteristics and norms that

aid in the recognition of the quantity, quality, and maturation level of organic matter in rocks

associated with petroleum production (Tissot and Welte, 1984; Hunt, 1996; Peters et al., 2005;

Bend, 2007).

1.2 Background

This study is a part of the Saskatchewan Phanerozoic Fluids Project, initiated by the University

of Alberta and University of Regina. The objective of the Saskatchewan Phanerozoic Fluids

Project is to enhance the understanding of how and where hydrocarbons were generated in the

2

subsurface of Saskatchewan as well as where and when they may have migrated over geologic

time, and to determine where they are most likely to occur at the present time. A critical

component of the Saskatchewan Phanerozoic Fluids Project is to gather geochemical and

petrographical data that will aid in assessing source potential for a given number of geological

formations that will become part of an integrated petroleum systems analysis for the Williston-

Basin of southern Saskatchewan (Whittaker et al, 2009).

1.3 Study Purpose

1.3.1 Purpose

The primary purpose of this study is to provide a preliminary, high resolution, geochemical

assessment of the source rock potential of the Torquay Formation in southern Saskatchewan,

using an integrated geochemical and petrographic approach.

1.3.2 Specific Objectives

1. Identify a sample of core with the highest recovery within the Torquay Formation.

2. To use the Rock-Eval pyrolysis at extremely close sampling intervals at the millimeter to

centimeter scale, obtained by using a drill-press, rather than the conventional large

sample interval ‘bulk rock’ method.

3. Determine the effectiveness of using high resolution geochemical data to subdivide the

Torquay Formation.

4. Determine if there is a relationship between geochemical, lithological as well as

petrophysical data, and if such a relationship concurs with the previously published

subdivision of the Torquay Formation.

3

1.4 Previous Studies

The analysis and assessment of the Torquay Formations source rock potential has been largely

ignored, leaving to speculation the origin of Torquay Formation oil within southern

Saskatchewan. A small number of studies were conducted to assess reservoir characteristics

within the Torquay Formation published by Kreis et al., (2006), but no previous assessment of

the source rock potential has been carried out. Facies correlations within the Torquay

Formation were the focus of multiple studies (Christopher, 1961; Kreis et al., 2006; Nicolas

2006, 2007; and LeFever and Nordeng, 2009), using both petrophysical wireline logs and limited

core data gathered from various locations within the Williston Basin. Figure 1 displays various

facies subdivisions as a result of previous work. Both Christopher (1961) and Kreis and Costa

(2006) focused on southern Saskatchewan and Lefever and Nordeng (2009) proposed their

subdivisions based upon work conducted in the United States portion of the Williston Basin. It

should be noted that the Torquay Formation appears to possess a greater degree of

subdivisions that is not prevalent in all locations across southern Saskatchewan (Christopher,

1963). Nicolas (2012) made further subdivisions of units 1, 2, and 4 within the Torquay

Formation within the portion of the Williston Basin that lies in Manitoba. The principal

borehole analyzed in this study (i.e., 13-19-9-30W1) lies near the Manitoba border, therefore

the subdivisions proposed by Nicolas’ (2012) study have been adopted in this study.

4

1.5 Stratigraphic Setting

The dolostones and doloarenites of the Torquay Formation make up a portion of what is the

Three Forks Group, which are Upper Devonian (Fammenian) in age. The Three Forks Group is

also comprised of the well-known and prominent Bakken Formation as well as the red and

green shales of the Big Valley Formation (Figure 3). The Torquay Formation ranges in thickness

from 25m to 80m and rises from 1676m below sea level at 1-14-1-8W2, proximal to the

International Border, to 61m above sea level in the northern portion of the Williston Basin

Figure 1 – Unit Classifications through the Torquay Formation based on work from Christopher (1961), Kries and Costa (2006), and Leferver and Nordeng (2009). Modified from Nicolas (2012).

5

(Christopher, 1963). In south eastern Saskatchewan, the Torquay Formation is stratigraphically

overlain by the Big Valley Formation and unconfomably overlain by the Bakken Formation

(Figure 2) in places. The unconformity between the Torquay Formation and Bakken Formation

is more prominent within the more southern portions of Saskatchewan, whereas towards the

northern rim of the Williston Basin and along the sub-crop, the Big Valley Formation

conformably overlies the Torquay Formation. Lithologies along this startigraphic contact are

marked by a lithologic shift characterized by a change from green argillaceous rocks to a more

silt dominated lithology, although this contact was not observed in this study. Conformably

below the Torquay Formation occur the evaporates of the Saskatchewan Group’s Birdbear

Formation, marking a shift to from the anhydrite rich dolomitic silts and sands of the Birdbear

Formation to the oxidized brecciated siltstones of the Torquay Formation.

Figure 2 – Stratigraphic chart of southeastern Saskatchewan. Black dots represent oil production form those Formations. Modified from www.er.gov.sk.ca/stratchart.

6

1.6 Study Area

Samples were collected from wells 04-02-001-10W2, 8-11-001-09W2, and 13-19-009-30W1,

spanning the northern rim of the Williston Basin from the Manitoba/Saskatchewan border to

the deepest portion of the sub-crop within Saskatchewan and proximal to the US/Canada

border. Figure 3 shows a map of both the sampled well locations and also those wells in which

petrophysical data was used to aid in geochemical facies correlations.

Figure 3 – Isopach map of southeast Saskatchewan representing the Torquay Formation total Thickness. The black dashed lines indicate the furthest extent of the Lower Bakken Formation and the grey dashed lines represent the extent of the Big Valley Formation. Sampled and studied wells are ploted over the map. Modified from Kries et al. (2006).

7

2. Method

2.1 Core Analysis

Recovered core from well 13-19-9-30W1 was studied and logged in detail (Appendix III) from

1013.5 m to 1028 m and from 1048 m to 1050 m. No core was available between 1028 m and

1048 m giving 45% recovery for this well location. The well was chosen based on the amount of

recoverable core it had relative to other cored sections of the Torquay Formation. Core

samples were collected and washed after slabbing the core lengthwise with a water lubricated

rock saw. Individual samples for Rock-Eval analysis were obtained from the sampled core using

a drill press fitted with either a 5.0 or 2.0 mm masonry drill bit. A total of 172 samples were

collected from well 13-19-9-30W1. Extracting samples in this fashion enabled the sampling of

individual laminations, rather than the normal method of obtaining samples in bulk over a

much larger interval (Figure 4), thereby enabling the creation of a more detailed geochemical

Figure 4 - Sample of core from well 13-19-9-30W1 where the microdrill was utilized to take powdered samples of differing lithologies. (Original image in colour)

8

profile as well as providing, on a millimeter scale, the recognition of minor changes in Total

Organic Carbon, and the Rock-Eval parameters S1, S2, and Hydrogen Index (parameters

explained in Chapter 2.2) throughout the Torquay Formation. A total of 172 samples were

obtained in this way from well 13-19-9-30W1 and geochemically assessed using Vinci Labs

Rock-Eval VI analyses.

The basis for sample collection was established upon lithological variability and the presence of

sediment capable of containing elevated amounts of organically derived carbon as well as the

occurrence of red oxidized sediment. The oxidized sediment was sampled on a much larger

scaled interval due to the lack of organic matter preserved in such a lithology. Geochemical

data derived from the Rock-Eval analyses was compared to wireline log signatures as well as

detailed core descriptions to obtain an assessment of paleoenvironment, controls on sediment

and organic matter deposition and alteration, as well as the possible cyclic trend in

sedimentation and organic accumulation.

Petrophysical wireline logs were used to help provide and extend correlations in places where

core was not available for study. These ‘un-cored’ portions of the Formation were primarily

located at stratigraphically lower depth and occur below the first appearance of oxidized

mudstones (or red-beds), most likely no core was cut within these lower units due to their

perceived low economic significance.

9

2.2 Rock-Eval Pyrolysis

The methods utilized for RockEval pyrolysis follows an industry standardized methodology, as

outlined by Espatalie et al., (1977) and Peters et al., (2005). Rock-Eval pyrolysis was originally

developed as a method to quickly and inexpensively characterize source rocks using drill

cuttings over intervals of one to five meters (Espitalie et al., 1977). Since the development of

the technique in the late 1970’s, Rock-Eval pyrolysis has been universally utilized as a ‘bulk rock’

pyrolysis technique to provide a rapid means of geochemically screening large sample sets,

providing an assessment in the quantity and quality of organic matter within a sample. In this

study, Rock-Eval pyrolysis was utilized in conjunction with a high-resolution cm to mm scale

sampling protocol throughout the Torquay Formation, forming a high resolution geochemical

data set at the micro-analysis scale to generate both a high resolution geochemical profile over

a zone of interest and asses the effectiveness of the Rock-Eval method with a micro-sampling

protocol as a form of micro-analysis.

This study utilized a Vinci Laboratory Rock-Eval VI analyzer (Figure 5 ) to conduct the Rock-Eval

Figure 5 – Vinci Laboratories Rock-Eval Pyrolyzer at the Department of Geology, University of Regina

10

pyrolysis. The procedure is relatively simple. A powdered rock sample ~ 50 ±3 mg is heated in

an inert atmosphere (nitrogen) causing the thermal decomposition (i.e., pyrolysis) of organic

matter. The organic matter decomposes due to the sequential rupture of molecular bonds of

increasing binding energy, as the temperature increases from ambient at 25oC per minute up to

850oC. During pyrolysis, the products are detected by a flame ionization detector (FID) as well

as an infared (IR) cell, which together generates a number of analytical parameters, which

include: S1 (mgHC/g rock) representing free or in-situ hydrocarbons S2 (mgHC/g rock)

representative of the generation potential largely considered as kerogen and Tmax which is the

S2 peak maxima and taken as an index of thermal maturity. During the subsequent oxidation

process, the IR cell monitors the amounts of CO2 and CO that evolve during the final

decomposition of organic matter which give the S3 (mgCO2/g rock) and S4 peaks (Peters et al.,

2005).

Each analysis generates a pyrogram (Figure 6) showing the pyrolysis of organic compounds with

time increasing from left to right along the x-axis, and material yield along the y-axis. Important

acquisition parameters obtained during analysis are; S1, S2, S3, S4 (Vinci Labs, 2010). A sample

Figure 6 - Schematic pyrogram displaying the evolution of hydrocarbons and CO2 from a sample during Rock-Eval pyrolysis (Hunt, 1996).

11

of an immature source rock typically will yield a low S1 peak and an elevated S2 peak, in

comparison, a sample of kerogen with a higher level of thermal maturity will result in a larger

S1 peak at the expense of the S2 peak. Tmax would also register a shift towards a higher

temperature (e.g. 420 to 435°).

A set of parameters are subsequently calculated from the acquisition data following pyrolysis,

which includes Production Index (PI), Hydrogen Index (HI), and Oxygen Index (OI). Total Organic

Carbon (TOC), expressed in weight percent (wt. %) is an important parameter that indicates the

total quantity of organically derived carbon within a sample. The Hydrogen index (calculated by

[S2/TOC X 100]) and the Oxygen index (calculated by [S3/TOC X 100]) are two valuable indices

that are utilized to determine the quality and genetic potential of a given kerogen, which helps

to identify the type of hydrocarbon (i.e., gas or liquid) that can be generated (Tissot and Welte,

1984).

Figure 7 – A combination of an analysis flow chart indicating the pyrolysis process, examples of Pyrolysis and Oxidation curves (S1, S2, S3CO2, S4CO2), and derived and calculated parameters of the Rock-Eval Pyrolyzer. (Aderoju and Bend, in press 2012)

12

2.3 Microscopy/Petrography

The estimation and analysis of visible organic matter within’ whole rock’ samples was conducted

using reflected light microscopy. Samples from core were cut using a rock saw parallel to the

depth direction (Figure 4), and were subsequently polished on a Buehler Roll Grinder equipped

with corundum sandpaper of varying grit sizes progressing from 240 to 600 grit. Once polished,

samples were adhered to a glass slide using a Leitz leveling press and adhesive putty.

Petrography was carried out in a darkened room using a Lietz Orthoplan microscope (Figure 8).

To conduct the analysis, the microscope was equipped with a 50 Watt mercury HBO lamp,

Ploem 4-Lambda UV/Fluorescence illuminator consisting of an UV/ violet excitation filter

(bandwidth λ = 400-490 nm), a dichroic mirror (bandwidth λ = 510 nm) and a yellow barrier

filter (bandwidth λ = 520 nm), x16 air incident light objective, giving an overall magnification of

x240. Plain light microscopy was conducted using a Leica M420 microscope equipped with a

Leica ClS light source operating at x150 (Figure 9).

Figure 8 – A Lietz Orthoplan microscope equipped with a Ploem 4-Lambda UV/Florescence illuminator an x16 air incident light objective at the Department of Geology, University of Regina. Original image in colour

Figure 9 – A Leica M420 microscope equipped with a Leica CIS 150x light source at the Department of Geology, University of Regina. Original image in colour

13

Select samples from wells 4-2-1-10W2, 13-19-9-30W1, and 8-11-1-9W2 were petrographically

analysed in both incident white light and autoflourescent incident light. For wells 4-2-1-10W2

and 8-11-1-9W2 the concentration of analyses was on the upper most 10 cm below the

stratigraphic top of the Torquay - Lower Bakken Formation contact. For well 13-19-9-30W2, the

geochemical analysis emphasis was to create a geochemical profile throughout the Torquay

Formation.

3. Results and Discussion

3.1 Lithological Characterization

Compiled from wells 13-19-9-30W1, 4-2-1-10W2, and 8-11-1-9W2

The Torquay Formation is primarily composed of brecciated dolostones and doloarenites with

argillaceous interbeds. Primarily, dolomite occurs as very fine, well cemented, doloarenite

integrated with mudstones and shale as well as pebble to cobble sized fragments (ranging from

angular to subrounded) embedded within a silty mudstone (Figure 10). Intervals of intense

brecciation are often accompanied by argillaceous rip-up clasts suggesting the presence an

erosional current during deposition. Some cross bedding within the dolarenite intervals are

visible, though infrequent and occurring over a centimeter scale. Bedding structures are not

preserved or visible throughout the Torquay Formation. A majority of the weathered

argillaceous groundmass contains poorly sorted silt sized particles, dolomitic particles, as well

as very fine grained quartz sand particles. The clay mineral matrix, as well as aggregate

14

material, is well cemented and tightly compacted. Such a lithology is reportedly associated

with low porosity values (Christopher, 1963). Lithological changes throughout the Torquay

Formation are abrupt and frequent; composite logs in Appendix I and II illustrate the frequent

changes in lithology throughout the upper portions of the Torquay Formation especially in the

upper section of the Formation (1013.5 m to 1023.5m in well 13-19-9-30W2 and 2274.75 m to

2290.00 m in well 4-2-1-10W2). There is a gap in cored material through the Torquay

Formation that leaves sections without a detailed description (Appendix II).

Dolomitic layers occurring at 1013.5 m to 1023.5m in well 13-19-9-30W2 and from 2274.75 m

to 2290.00 m in well 4-2-1-10W2 range in colour between light grey and tan/orange-brown.

The colouration of the interbedded mudstone suggests an alternation between periods of

oxidizing conditions (red-brown) and reducing conditions (green–brown) (Figure 10). Such

colouration was attributed by Christopher (1963) as relating to two distinct chemical

environments by: (a) a dominance of carbonate components that inhibited the oxidation of

ferric compounds (through the production of a reducing agent such as HCl), yielding a green

Figure 10 – Whole rock samples from well 13-19-9-30W1. (Depths 1015.28 m to 1015.19 m on left and depths 1018.47 m -1018.54 m on the right). Original image in colour.

15

colouration of the argillaceous material; and (b) a low concentration of carbonate ions

dampened the reducing effect and along with strong oxidation to the ferric compounds the

argillaceous material assumed a red – brown colouration. Reduction by organically derived

reagents appears to have occurred through the upper one quarter to one half of the Formation

(Fuller, 1956). The oxidation surface rises and falls with the type of overlying lithology within

the Torquay Formation (Christopher, 1963). For example, in localities where the Torquay

Formation is overlain by the Lower Bakken Formation shale, the oxidized zone lies within the

lower two-thirds of the Formation, in contrast where the Torquay Formation is overlain by the

Big Valley Formation green shales and Bakken Formation middle member; the heavily oxidized

lithologies lie within the upper one quarter of the Torquay Formation. Low concentrations of

organic matter inhibit dolomitization in digenetic systems and promote an oxygenated

environment (Slaughter and Hill, 1991). The reducing environment that formed the black shale

of the lower Bakken Formation probably penetrated the sea floor thus causing a deeper

reducing zone in the Torquay Formation than in locations where the middle sands of the

Bakken Formation overly the Torquay Formation. Large quantities of organic matter, especially

protein rich, produce reducing conditions from the enzymatic degradation of protein (Slaughter

and Hill, 1991). Alternatively, the generation and presence of euxinic conditions during the

deposition of the lower Bakken Formation would generate the same conditions (Aderoju and

Bend, 2014). Wells 4-2-1-10W2 and 13-19-9-30W1 (Appendix I and II) illustrate this redox

difference since the more western location of the two wells do not contain oxidized zones in

the cored section of the Torquay (27m) whereas in well 13-19-9-30W1, the oxidation beds

appear four meters below the middle Bakken – Torquay Formation contact.

16

3.2 Assessment of Rock-Eval Parameters

Total organic carbon (TOC) values throughout the Torquay Formation are relatively low, ranging

between 0.08 wt. % and 1.68 w.t % (Figure 11). Both Hunt (1979) and Tissot and Welte (1984)

state that the minimum TOC value necessary for an argillaceous rock to be considered a

potential source rock when deposited under reducing conditions is 0.5 wt. % for shales and 0.3

wt. % for carbonates. Between 1015.5 to 1016.5 m, associated with numerous thinly bedded

fine argillaceous interlaminations, is a zone with relatively high TOC (1.68 w.t %), values that are

generally higher than the remainder of the upper Torquay Formation (Figure 12). Coupled with

low values of Tmax throughout the Torquay Formation (i.e., below 425° Celsius), high S1 values

indicate an organic matter that is thermally immature and associated with a poorly developed

hydrocarbon content (Peters et al., 2005) or hydrocarbons that have migrated into the

1012

1013

1014

1015

1016

1017

1018

1019

1020

1021

1022

1023

1024

1025

1026

1027

1028

1029

0 0.5 1 1.5 2

De

pth

(m

)

Total Organic Carbon (wt. %)

Figure 11 - An x-y scatter plot illustrating the concentration of elevated TOC levels at the depth of analysis.

17

formation (Hunt, 1996).

Results calculated from Rock-Eval Pyrolysis are displayed in Figures 12 and 13 as a series of

geochemical logs that suggest a cyclical nature of organic matter accumulation within the

Torquay Formation. The rising and falling in organic matter content (relatable to TOC) can

possibly be attributed to varying conditions that either favour or diminish organic matter

accumulation during deposition. Appendix II shows the possible cyclical relationship between

the occurrence of organic matter accumulation and lithological changes within the Torquay

Formation. Lithologies associated with a very fine grain size (i.e., argillaceous/silt) see a rise in

TOC, Hydrogen Index (mg HC/g rock), S1, S2, and in addition, a decrease the Oxygen Index. This

is consistent with the traditional observation that a reduction in grain sizes leads to more

De

pth

(m

)

Figure 12 – Geochemical log for the Torquay Formation at well 13-19-9-30W1, showing the range in values for Hydrogen Index , Oxygen Index, TOC, S1, S2, and Production Index between 1013.5 m and 1028 m.

De

pth

(m

)

18

favourable conditions for greater accumulations of organic matter depending on the

environment (Peters et al., 2005). In the case of the Torquay Formation, a decrease in grain

size is usually associated with the presence of argillaceous laminations. In Chapter 3.4, this will

be examined further.

All depths in which there was an observed hydrocarbon show (i.e., 1013.5 m, 1015.2 m to

1017.0 m) the TOC, HI, S1, and S2 values are relatively high, typically representing the largest

values for each parameter in well 13-19-9-30W1. High S1 values at these depths as well as high

Figure 13 – Geochemical log for the upper five meters of the Torquay Formation at well 13-19-9-30W1 between 1013.5 m and 1018.5 m. Note the cyclic organic matter accumulation nature visible at an increased resolution indicated by arrows

De

pth

(m

)

19

TOC percentages indicate the presence of allochthonous (migrated) petroleum based on an

assessment using the Migration Index (S1/TOC) (Figure 14) (Hunt, 1996). Such values could

typically be attributed to the presence of petroleum that has migrated into the Torquay.

Petrographic analysis indicates that the residual petroleum occurs as a coating around mineral

grains, though in low amounts. However the permeability values at these depths range from

0.19 mD to 0.69 mD, which is relatively low but within the range typical for petroleum source

rocks (Hunt, 1995). At such low permeabilities, the presence of migrated hydrocarbons would

necessitate the existence of a viable fracture permeability rather than matrix permeability

(Jones, 1986). However the Migration Index (Figure 14) could also indicate the presence of

indigenous hydrocarbons that are the result of generation at very low levels of thermal

maturity. An index between 0.1 and 0.2 typically indicate a zone in which oil expulsion has

occurred (Hunt, 1996). A majority of the Torquay Formation falls beyond of this zone indicating

1012

1014

1016

1018

1020

1022

1024

1026

1028

1030

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

De

pth

(m

)

Migration Index

Zone of Oil Expulsion

Figure 14 – The derived Migration Index plotted against depth for well 13-19-9-30W1. The space in between the purple vertical lines indicates the zone where oil is expelled from the rock.

20

the presence of high S1 values (hydrocarbon) relative to S2 (kerogen). Combining this data with

both Total Genetic Potential (TGP) (S1+S3) and Hydrocarbon Type Index (HCTI) (S2/S3) provides

a further evaluation of the hydrocarbons within this narrow zone of the Torquay Formation.

The Hydrocarbon type index (Figure 15) suggests that the majority of organic matter within the

Torquay may generate gas, which largely reflects the relatively high Oxygen Index values, with

exception to depths 1014 m, and 1017 m. A calculation of the Total Genetic Potential, which is

a combination of both S1 and S2 values is shown in Figure 16, suggests that samples within this

zone of interest fall within the range from ‘Very Good’ to ‘Good’ source rocks, in contrast to the

majority of the Torquay Formation appears to have a ‘low’ hydrocarbon generative potential.

An alternative explanation for the presence of hydrocarbons (Figure 14) within this zone of

interest (i.e., 1014 to 1017 m) necessitates the generation of hydrocarbons at very low levels of

1012

1014

1016

1018

1020

1022

1024

1026

1028

0 1 2 3 4 5 6 7 8 9 10 11 12 13

De

pth

(m

)

Hydrocarbon Type Index

Gas Gas and Oil Oil

Figure 15 – The Hydrocarbon Type Index for well 13-19-9-30W1 indicates the quality of the hydrocarbons present in the rock by indicating which petroleum product they are capable of producing as thermal maturation progresses.

21

thermal maturity. This initially appears problematic in that the Tmax values for this zone range

from 294°C to 402°C which is well below the 425°C threshold normally associated with the

onset of oil generation (Tissot and Welte, 1984; Hunt, 1996; Peters, 2005; and Bend, 2007). The

presence of weaker bonds, such as C–S bonds, with low binding energy, are acknowledged as

capable of generating hydrocarbons at very low levels of thermal maturity (Orr, 1982). Sulfur is

typically higher in Type II kerogen types (Peters et al., 2005). Unusually high sulfur content in

certain types of Type II kerogens may explain the tendency of these kerogens to generate

petroleum at relatively low levels of thermal maturity (Orr, 1986; Peters et al., 1990; Baskin and

Peters, 1992) even though increased atomic O/C has been associated (Jarvie and Lundell, 1991).

Within the Torquay Formation, the sulfur content is high (6.0%), below the Lower Bakken

Formation black shale.

1012

1014

1016

1018

1020

1022

1024

1026

1028

0 1 2 3 4 5 6 7 8 9 10 11 12

De

pth

(m

) Genetic Potential

Poor Fair Good Very Good

Figure 16 – The calculated Genetic Potential of Rock Eval samples from well 13-19-9-30W1. Indicates the source rock potential for a particular sample at a particular depth based on quantity.

22

3.3 Petrographic Analysis

The petrographic analysis for samples selected from wells 13-19-9-30W1, 4-2-1-10W2, and 8-

11-1-9W2 revealed the presence of low amounts amorphous organic matter, generally

characterized by a moderate yellow-orange fluorescence. Fluorescing colour is a function of

kerogen type and thermal maturity. A yellow – orange colour is often associated with kerogen

that is either within the oil window or underwent insipient alteration (Bend, 2007). Such a

finding strongly suggests that the organic matter within the Torquay Formation has undergone

some form of ‘degradation’ with the loss of hydrogen-rich material, yielding, in places, a false

Type III kerogen analysis which may be caused by post-depositional reworking.

a

c

b

d

Figure 17 – UV/Fluorescence microscopy images taken at x240 magnification. a) Tasminites in-filled with silt at a depth of 2274.74 m (Well 4-2-1-10W2) b) Tasminites ‘draped’ around a clast at depth 2274-76 m (Well 4-2-1-10W2) c) Broken algal bodies within a silty matrix at a depth of 2274.765 m (Well 4-2-1-10W2) Parasinophyte at the contact between the Lower Bakken Formation (dark colouration) and the Torquay Formation (Well 8-11-1-9W2)

40 μm

23

The Torquay Formation near the Lower Bakken Formation was the primary zone of interest in

wells 4-2-1-10W2, and 8-11-1-9W2. A presence of fractured algal bodies and Tasminites within

the silt sized particles of the Torquay Formation (Figure 17 and 18), is increased with proximity

to the lower Bakken shale. This trend was not seen at the top of well 13-19-9-30W2 as this

zone has been eroded away.

Intact algal bodies are observed at a depth of 1015.21 m within argillaceous material along the

edges of transported dolomitic siltstone (Figure 17). This is the only observed occurrence of

intact algal bodies within well 13-19-9-30W1. The majority of the cored portion of the Torquay

sees broken algal bodies and amorphous organic material along grain boundaries and fractures

(Figure 18). This is indicative of migratory petroleum that at one point moved through the

system but no longer there in economical amounts. Between depths of 1015.5 m to 1016.5 m,

which corresponds with the highest values for TOC, amorphous organic matter is observed

coating grain boundaries and at fractures, amorphous organic matter has the greatest tendency

to generate hydrocarbons at low levels of thermal maturity (Orr, 1982).

a bFigure 18 – UV/Fluorescence images at x240 magnification from well 13-19-9-30W1. a) Parasinophyte within an argillaceous lamination (1015.21 m). b) Fluorescing hydrocarbons along a fracture in a clay-silt matrix (1016.15 m).

40 μm

24

3.4 Kerogen Analysis

Kerogen is the ‘sedimentary organic matter that is insoluble in common organic solvents and

aqueous alkaline solvents’ (Tissot and Welte, 1984). An assessment of kerogen Type is

conducted to assess the source potential of a given rock. The pyrolysis parameters, Hydrogen

Index and Oxygen Index are plotted against one another on an x – y scatter plot (HI/OI plot) and

thereby designated into one of three Kerogen Types, which indicates the hydrocarbon

generation potential of organic matter within the source rock.

The Hydrogen Index v. Oxygen Index cross-plot suggests that the kerogen content within the

0

100

200

300

400

500

600

700

800

900

0 50 100 150 200

Hyd

roge

n in

de

x, m

g H

C/g

TO

C

Oxygen index, mg CO2/g TOC

Kerogen Typing

Figure 19 – A HI/OI plot indicating kerogen type through well 13-19-9-30W1 for the Torquay Formation (Depths: 1013.5m to 1026.5 m). Only values that plotted within this graph area were used.

I

II

I

III I

25

Torquay Formation ranges from Type II to Type III with minor amounts of ‘residual’ or non-

generative Type IV (Figure 19). Type III kerogen is typically associated with terrigeneous organic

matter, which neither fits with the stratigraphic age of the Torquay Formation or its probable

sabkha-like depositional setting. The absence of terrestrial material was confirmed using UV

Florescence microscope analysis. Oxidized or moderately oxidized Type II (or Type I) kerogen

will result in a false Type III assessment (Figure 19) due to the high incidence of post or syn-

depositional oxidation within Torquay Formation.

3.5 Geochemical Subdivisions of the Torquay Formation

In this study, the detailed geochemical analysis of source potential primarily focused on the

upper cored portion of well 13-19-9-30W1 from 1013.5 m to 1018.5 m, which represents Unit 5

and 4 as subdivided by Nicolas (2012) (See Section 1.5). Nicolas (2012) further subdivided this

unit into Subunit 4a, 4b, and 4c, based upon a combination of geochemical, lithological and

petrophysical data. A division into four subunits within Unit 4 is herein suggested (Figure 20).

Descriptions of the four proposed sub-units follows:

Subunit 4a - Characterized by a shift from a brecciated dolomitized siltstone to a more massive

green siltstone, and geochemically characterized by a peak in the Oxygen Index and a low

plateau in the TOC content. In this transitional subunit, values for S1 and S2 are very low,

exhibiting little change that suggests an organic poor interval and a period of rebound from the

oxidized Unit 3.

26

Subunit 4b - Characterized by tan coloured brecciated dolomitized siltstone within a green

matrix. The Hydrogen Index appears generally low throughout, rising slightly to 100 towards

1016 m with a moderately high Oxygen index, which is likely due to a high level of reworking or

the dolomitization of the host sedimentary rock.

Subunit 4c - This sub-unit is represented by the presence of argillaceous laminations

throughout the dolomitic, brecciated siltstone. This zone exhibits both the greatest range and

Figure 20 - Subdivisions made to Unit 4 of the Torquay Formation based on geochemical data from well 13-19-9-30W1. These divisions also relied on lithological and petrophysical data (Figure 2, Appendix I).

Sub-divisions based on Rock-Eval data

27

the highest level of Total Organic Carbon, the highest associated values for HI, S1, S2 and the

lowest values for the Oxygen Index. Oil shows were prominent through this subunit as well as a

petroliferous odour. The Production Index remains above 0.6 throughout and the Migration

Index (Figure 14) remains high. This sub-zone also has the highest Hydrocarbon Type Index.

Pyrite begins to become more prominent with decreasing depth within this sub-unit.

Subunit 4d - Dolomitized, green siltstone with a tan brecciated siltstone (tan) throughout; the

argillaceous content is less than from the previous sub-unit and grain size increases within the

matrix. This sub-unit generally exhibits S1 and S2 values that decrease with depth as well as

relatively low levels of Total Organic Carbon. This possibly indicates the occurrence of low

organic sedimentation rates through this zone and an increase in depositional energy. High

oxygen index values through this sub-unit support this suggestion.

Unit 5 - Dolomitization through this unit appears to have decreased relative to Unit 4, which is

also characterized by an influx of very fine grained quartz sand. Cross bedding appears within

this sub-unit as well as discontinuous ripple bedding. Geochemically, this sub-unit is

characterized by an increase and subsequent decrease in the Hydrogen Index. Values for S1

and S2 exhibit a similar trend. Pyrite occurrence is quite high through the this unit and quite

high in this locality, and the second highest concentration to Unit 6 which is occurs deeper

within the Williston Basin.

This study only observes Unit 6 in wells 4-2-1-10W2 and 8-11-1-9W2. However, no geochemical

information has been acquired for these wells, therefore defining subunits is limited. Appendix

I and II illustrates where the subunits of the Torquay Formation exist in the cored section of the

well.

28

3.6 Production Index and the Relation of Source potential

The Production Indexes (PI) values for the upper Torquay Formation show considerable

variation (Figure 21), with the majority of values plotting outside the zone of significant oil

generation (i.e., between 0.1 to 0.4) (Espitalie et al., 1977). However, many of the plotted

values may not be accurate since most S2 values are less than 0.2 mg HC/g rock. Such very low

values indicate that very little organic matter within Subunit 4d of the Upper Torquay at 13-19-

009-30W1 has or is capable of significant oil generation. Production Index values viewed along

side the Total Organic Carbon and Hydrogen Index values show that samples with the greatest

S1 values (i.e., free hydrocarbons) have PI values above 0.4, indicating samples at this depth

and locallity are incapable of sigificant oil generation. High PI values are typically associated

with migrating hydrocarbons (Figure 21) (Peters, 2005).

It is also nteresting to note the that aibrupt decreases in Production Index values conincide with

changes in lithofacies (Figure 20) (Appendix II).

1014

1016

1018

1020

1022

1024

1026

1028

1030

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

De

pth

(m

)

Production Index

Production index vs. Formation depth

Zone of Significant Oil Generation

Possible upper limit of significant oil generation

Figure 21 - Figure 21 – Production Index related to depth for the Torquay Formation at well 13-19-9-30W1. The gap between the two blue dashed lines suggests the upper limit of oil generation. The gap between the two black lines is the zone of oil generation as determined by Espitalie et al., 1977.

29

3.7 Comparative analytical approach (The assessment of two methodologies)

3.7.1 The assesment of source potential in ‘microhorizons’ versus the conventional and widely used bulk rock approach.

This study utilized a sampling methodology that allowed for a significant increase in data

resolution. The use of a micro drill enabled the direct sampling of thin, distinct argillaceous

laminae without the dilution of organic material by silliciclastic and/or carbonate material

which typically occurs using the bulk-rock method. The traditional bulk-rock method of analysis

involves the crushing of rock material, such as drill cuttings, that were obtained over a sample

interval of 1 to 5 meters, with the associated dilution of indigenous organic matter. Sampling in

this fashion will lead to reduction in TOC, a loss in resolution, and the inability to accuratley

detect thin interbeds with high TOC amongst the interleaving non-source material rather than

providing a true assesment of the organic rich material within the zone of interest. No previous

analysis for the Torquay exist that would permit a comparison, however, Latimer (2013),

compared the analysis derived using the bulk-rock method against the microhorizon method

within the Birdbear Fomation of Southern Saskatchewan. Within that study, bulk rock samples

yielded a TOC of 3.63 wt. % whearas this microhorizon method gave a TOC of 16.87 wt. % from

a centimeter scale argillaceous lamination within that bulk-rock sampled depth interval. Such a

difference in values confirms the dilution of samples that occurs with use of the bulk-rock

method of analysis .

However, microhorizon scale sampling may impact the established normative threshhold values

of TOC considered necessary in an effective source rock. If the published norms for assessing

the generative potential of a source rock are used to assess samples acquired through the

30

microhorizion method of analysis, they may be greatly undervalued. Classification of the

generative potential according to Peters et al. (2005) is as follows:

Potential (quantity)

TOC (wt. %)

Poor <0.5 Fair 0.5-1

Good 1-2 Very good 2-4 Excellent >4

The application of such values suggests that some intervals within the Torquay Formation have

good source potential, although petrographic analysis indicates that this is not the case. It

becomes clear that although thin isolated laminations may contain very high TOC values, by

virtue of thickness and their association with organically lean adjacent laminae such fine

laminations are may be incappable of expelling petroleum generating hydrocarbons.

Adjustments must therefore be made to source rock classifications that accommodate rock

mass when using a microhorizon sampling method.

3.7.2 Implications of the use of geochemical data to subdivide units

The use of geochemical information, petrophysical data and lithological descriptions provided a

more accurate means of subdividing Unit 4, as shown in Figure 20. The high resolution

geochemical data not only indicates changes in litholgy but also reflects changes in organic

matter accumulation rates. Such geochemical changes are also not visible in most cases in

petrophysical logs since logs do not provide a resolution below 1 meter. Using high resolution

microhorizon analysis provides greater efficiecy in determining divsions and subdivisions within

a formation. Employing this method on more heavily disputed facies boundaries in other

formational units could potentially put many controversies to rest.

31

4. Conclusions

- This preliminary assessment of the source rock potential of the Torquay Formation

determined that the petroleum source rock potential is low overall. Only small isolated

argillaceous laminations would appear capable of producing petroleum, though not on an

economical scale.

- Rock-Eval pyrolysis method utilized in this study displayed effectiveness of the Micro-horizon

sampling method through the Torquay Formation by identifying a high degree of variability in

TOC and enabled the definition of subdivisions through the formation based on geochemical

parameters. The traditionally used bulk-rock sample method is incapable of achieving either.

-The Rock-Eval derived geochemical data was shown to relate to lithology possibly indicating

shifts from low organic accumulation rates to higher rates and vice-versa where lithology was

unchanging.

-The traditionally used Rock-Eval data norms that that are used to assess source potential may

need to be adjusted to reflect data derived from a high resolution micro-horizon sampling

method due to the absence of dilution.

5. Future Work

This study provided a preliminary assessment of the source potential of the Torquay Formation.

However, this study has also identified areas of further potential research which included:

32

1. Detailed geochemical analysis of Unit 4c to determine the origin of the high values for

S1.

2. Conduct further work to determine if the geochemical anomaly within Unit 4c continues

down dip and into the paleo-shelf environment.

3. Conduct a comparative assessment using traditional (bulk) sampling method and the

microhorizon methodology.

4. Examine reasons for such low Tmax values through the Torquay Formation.

33

References Cited

Aderoju, T., Bend, S., 2012, Investigating the effect of organic sulfur compounds on oil generation in Bakken Formation in Saskatchewan. In: AAPG Annual Convention and Exhibition, April 2 -25, 2012, Long Beach, California.

Aderoju, T., Bend, S., 2014, Organic matter variations within the Bakken shales of Saskatchewan: with implications upon origin and timing of hydrocarbon generation. In: AAPG Annual Convention and Exhibition, April 7-10, Houston, Texas.

Baskin, D. K., and Peters, K. E., 1992, Early generation characteristics of a sulfur-rich Monterey kerogen: AAPG Bulletin, v. 76, p. 1-13.

Bend, S.L., 2007, ‘Petroleum Geology eTexbook’; Introductory etextbook on petroleum geology, AAPG Special Publication: Discovery Series #11, American Association of Petroleum Geologists, Tulsa, OK, USA, 210p.

Christopher, J.E., 1961, Transitional Devonian-Mississippian Formations of southern Saskatchewan; Saskatchewan Mineral Resources, Report 66, p. 103.

Christopher, J.E., 1963, Lithological and geochemical aspects of the upper Devonian Torquay Foration, Saskatchewan, Journal of Sediment Petrology, Vol. 33, p. 5-13.

Espitalie, J., Madec, M., Tissot, B. and Leplat, P., 1977, Source rock characterization method for petroleum exploration. In: Proceedings of the Offshore Technology Conference, May 2–5, 1977, Houston, TX, OTC, p. 439–44.

Fuller, J.G.C.M., 1956, Mississippian rocks and oilfields in southeastern Saskatchewan, Saskatchewan Department of Mineral Resources, Report 19, p. 72.

Hunt, J. M., 1979, in Petroleum geochemistry and geology, San Francisco, Freeman and Co., p. 348.

Hunt, J. M., 1996, Petroleum Geochemistry and Geology, New York, Freeman and Co.

Jarvie, D.M. and Lundell, L.L., 1991, Hydrocarbon generation modeling of naturally and artificially matured Barnett shale, Ft. Worth Basin, Texas, Southwest Regional Geochemistry Meeting, Sept. 8-9, 1991, The Woodlands, Texas, 1991.

Jones, R. W., 1986, Origin, migration, and accumulation of petroleum in Gulf Coast Cenozoic, AAPG Bulletin, vol. 70, p. 65.

Kreis, L.K., Costa, A.L., and Osadetz, K.G., 2006, Hydrocarbon potential of Bakken and Torquay Formations, southeastern Saskatchewan; in Gilboy, C.F. and Whittaker, S.G. (eds.), Saskatchewan and Northern Plains Oil & Gas Symposium 2006, Saskatchewan Geological Society Special Publication 19, p.118-137.

34

Latimer, A., 2013, An evaluation of source rock potential of the Devonian Birdbear Formation in southern Saskatchewan, Bachelors of Science thesis, Department of Geology, University of Regina.

Nicolas, M.P.B., 2006, Petroleum geology of the Devonian Three Forks Formation, Sinclair Field and surrounding area, southwestern Manitoba, in Saskatchewan Northern Plains Oil and Gas Symposium Core Workshop Volume, E.H. Nickel (ed.), Saskatchewan Geological Society, Special Publication 20, p.32-49.

Nicolas, M.P.B., 2007, Devonian Three Forks Formation, Manitoba (NTS 62F, parts of 62G, K), Report of Activities 2007, Manitoba Science, Technology, Energy and Mines, Manitoba Geological Survey, p. 171-179

Nicolas, M.P.B., 2012, Stratigraphy and regional geology of the Late Devonian- Early Mississippian Three Forks Group, southwestern Manitoba (NTS 62F, parts of 62G, K) Manitoba Innovation, Energy and Mines, Manitoba Geological Survey, Geoscientific Report GR2012-3, p.92

LeFever, J.A. and Nordend, S.H., 2010, Stratigraphic transect of the Sanish and Parshall Fields, Bakken Formation, Mountrail County, North Dakota, North Dakota Geological Survey, Geologic Investigations 93, Sheet 2.

Nicolas, M. P. B., 2012, Stratigraphy and regional geology of the Late Devonian-Early Mississippian Three Forks Group, southwestern Manitoba (NTS 62F, parts of 62G, K), Geoscientific Report - Manitoba Geological Survey.

Orr, W.L., 1986, Kerogen/asphaltene/sulfur relationships in sulfur-rich Monterey Oils, Organic Geochemistry, Vol. 10, Issue 1-3, p. 499-516.

Peters, K.E., Waters, C.C., Moldowan, J.M., 2005, The Biomarker Guide, Second Edition, I. Biomarkers and Isotopes in the Environment and Human History. Cambridge, UK Cambridge University Press.

Slaughter, M. and Hill, R.J., 1991, The Influence of Organic Matter in Organogenic Dolomiization, Journal of Sedimentary Petrology, vol. 61, no. 2, p. 296-303.

Tissot, B.P. and Welte D.H., 1984, Petroleum Formation and Occurrence, 2nd edition. Springer-Verlag, Berlin, 699 p.

Tyson, R.V., 1995, Sedimentary Organic Matter; Chapman Hall, London, 615p. Vinci Laboratories, Rock-Eval 6 User’s Guide. Whittaker, S., Marsh, A., Bend, S., and Roston, B., 2009, Saskatchewan Phanerozoic fluids and

petroleum systems assessment project. In: Summary of Investigations, 2009, Vol. 1, Saskatchewan Geological Survey, Saskatchewan Ministry of Energy and Resources, Misc. Rep. 2009-4.1, Paper A-1, 3p.

35

Appendices

Appendix I – Composite log for well 4-2-1-10W2

Appendix II – Composite geochemical log for well 13-19-9-30W1

Appendix III – Core descriptions for wells 4-2-1-10W2 and 13-19-9-30W2

Appendix IV - Rock-Eval Data for well 13-19-9-30W1

37

Appendix I

Composite logs for well 4-2-1-10W2

38

39

Appendix III

Core Descriptions

Well 4-2-1-10W2

2274 – 2274.74m

SHALE: Black laminated, organic rich

Top of Torquay

2274.74 –2275.70m

SILTSTONE: Tan – grey colouration, laminations of argillaceous material (wavy), pyrite stringers, very fine sandy laminations and interbeds periodically, grades into dolomitic sandstone

2275.70 – 2278.70m

SANDSTONE: dolomitic, very fine grained, grey, rip-up clasts present throughout, periods of medium to heavy brecciation of dolomitic siltstone, some green argillaceous laminations , micro pyrite present throughout.

2278.70 – 2279.92m

MUDSTONE: green argillaceous material with silt and very fine grained sandstone fine interbeds throughout

2279.92 – 2280.27m

SILTSTONE: dolomitic, tan-grey, pyrite infilled fractures, fine laminations of black argillaceous material (wavy).

2280.27 – 2280.47m

SHALE: massive, green/grey, finely brecciated with tan dolomitized silt, pyrite blebs.

2280.47 – 2280.54m

SHALE: massive, green/grey, pyritization occurs in small cm scale blebs

2280.54 - 2282.90m

MUDSTONE: wavy, interbedded, brecciated green clay with some lam of dolomitic very fine grained sandstone. Brecciated silt clasts have an orange colour to them.

2282.90 – 2284.11m

MUDSTONE: green-grey, with wavy interbeds of dolomitic sandstone and orange/tan dolomitic siltstone.

2284.11 – 2285.19m

SILTSTONE: dolomitic, tan to orange colouration, frequent wavy and planar laminations of green argillaceous shifting to black with depth.

40

2285.19 – 2285.56m

SHALE: black, laminated with fine orange dolomitic siltstone periodically.

2285.56 – 2287.30m

SILSTSTONE: dolomitic, tan/orange, frequent black shale wavy and planar laminations, some green argillaceous laminations as well.

2287.30m – 2287.54m

SHALE: brown-black, some fine laminations of tan/orange dolomitic sandy siltstone, some infrequent brecciation clasts of dolomitic siltstone.

2287.54 – 2289.05m

SANDSTONE: very fine grained, orange/tan, silty, wavy laminations of black argillaceous material.

2289.05 – 2289.80m

SANDSTONE: dolomitic, tan/orange, with frequent black cm scale shale laminations throughout

2289.80 – core base

SANDSTONE: dolomitic, massive, tan/orange

Well: 13-19-9-30W1

1013.5 – 1014.0m

SANDSTONE: very fine, silty, dolomitic, shale laminations (light green), oil stain, bright yellow fluorescence. Pyrite crystals common.

1014.0 – 1015.0m

SILTSTONE: dolomitic, brecciated, tan, mixed with lesser amounts green clay, oil stain, bright yellow fluorescence

1015.0 – 1016.80m

SILTSTONE: dolomitic, brecciated tan silt, cm scale green argillaceous interbeds throughout, fine pyrite crystals, oil show, yellow fluorescence.

1016.80 – 1018.45m

SILTSTONE: dolomitic, tan-grey, brecciation, wavy argillaceous laminations (green), grades to massive siltstone with depth.

1018.45 – 1020.9m

MUDSTONE: Red, low porosity, occasional light coloured brecciations

1020.9 – 1028.0m

MUDSTONE/SILTSTONE: altering beds of tan-green siltstone with green argillaceous material and red mudstones.

41

Appendix IV

Rock-Eval data for well 13-19-9-30W1

Depth Qty - (mg)

S1 - (mg/g)

S2 - (mg/g)

S3 - (mg/g) PI Tmax(°C) HI OI TOC(%) MINC(%)

1013.5 52.8 1 0.67 0.79 0.6 402 209 247 0.32 8.24

1013.55 52.4 0.75 0.29 1.03 0.72 300 54 191 0.54 4.77

1013.6 50.9 1.93 0.85 1.08 0.69 306 127 161 0.67 5.59

1013.65 50.3 1.3 0.76 1.05 0.63 372 190 262 0.4 6.18

1013.7 52.5 2.2 1.03 1.54 0.68 303 156 233 0.66 4.49

1013.75 51.3 2.08 0.79 0.92 0.72 308 155 180 0.51 5.11

1013.8 51.5 1.61 0.73 1.34 0.69 310 162 298 0.45 6.55

1013.85 50.7 1.2 0.74 1.4 0.62 402 168 318 0.44 9.32

1013.9 51.6 2.22 1.12 1.46 0.66 385 224 292 0.5 7.45

1013.95 51.4 1.67 0.74 1.24 0.69 400 195 326 0.38 7.6

1013.98 50.3 2.9 1.06 0.84 0.73 303 208 165 0.51 6.92

1014 52.2 3.73 1.9 0.88 0.66 383 268 124 0.71 6.4

1014.05 52.3 2.29 1.18 0.97 0.66 385 251 206 0.47 7.25

1014.06 51.7 0.63 0.41 1.46 0.61 416 146 521 0.28 8.36

1014.08 51 3.48 1.53 1.18 0.7 311 239 184 0.64 5.81

1014.1 50 1.37 0.72 0.69 0.65 398 206 197 0.35 7.58

1014.15 51.4 2.53 1.07 1.3 0.7 303 202 245 0.53 5.64

1014.2 52.1 1.28 0.53 1.41 0.71 309 132 352 0.4 5.67

1014.23 52.7 1.06 0.48 1.24 0.69 363 117 302 0.41 6.3

1014.25 53 2.16 0.98 1.34 0.69 321 166 227 0.59 5.47

1014.28 50.9 1.65 0.83 1.62 0.67 299 143 279 0.58 6.13

1014.3 50.6 2.36 0.95 1.12 0.71 303 127 149 0.75 4.35

1014.33 52.6 1.59 0.78 1.19 0.67 320 104 159 0.75 5.18

1014.35 51.5 0.14 0.2 1.22 0.41 337 74 452 0.27 6.05

1014.36 53 0.57 0.37 1.47 0.61 360 128 507 0.29 6

1014.4 52.1 0.09 0.08 1.34 0.52 297 12 197 0.68 4.33

1014.43 50 1.02 0.44 1.18 0.7 336 85 227 0.52 5.05

1014.45 51 0.18 0.15 0.58 0.54 338 83 322 0.18 6.59

1014.5 52.3 1.99 1.18 1.57 0.63 309 176 234 0.67 6.36

1014.54 50.6 0.87 0.48 1.15 0.65 361 130 311 0.37 6.3

1014.55 50.2 1.21 0.54 0.39 0.69 357 180 130 0.3 5.86

1014.6 53 3.53 1.49 0.98 0.7 304 122 80 1.22 4.83

1014.63 52.5 1.3 0.77 0.68 0.63 399 179 158 0.43 7.34

1014.65 50.8 0.59 0.19 1.04 0.76 303 63 347 0.3 5.25

1014.67 50.5 1.96 1.11 1.78 0.64 393 188 302 0.59 9.5

42

1014.69 52.8 1.85 0.78 1.19 0.7 312 142 216 0.55 6.6

1014.7 52.7 1.52 0.67 1.23 0.69 303 186 342 0.36 5.06

1014.75 52.5 1.28 0.48 0.95 0.73 319 89 176 0.54 4.69

1014.78 51.1 1.23 0.65 0.62 0.66 361 250 238 0.26 5.66

1014.8 52 1.08 0.46 0.9 0.7 326 135 265 0.34 4.75

1014.85 52.9 1.91 0.85 0.88 0.69 386 236 244 0.36 6.3

1014.9 53 1.66 0.7 0.7 0.7 322 121 121 0.58 5.38

1014.94 52.7 1.29 0.47 1.14 0.73 302 115 278 0.41 5.53

1014.95 50.1 1.13 0.71 1.11 0.61 379 173 271 0.41 6.14

1015 50 0.14 0.12 0.6 0.53 340 71 353 0.17 5.88

1015.05 52.5 0.15 0.1 1.21 0.58 318 45 550 0.22 6.18

1015.08 52.6 0.85 0.35 1.1 0.71 302 50 157 0.7 3.18

1015.1 52.7 0.25 0.14 1.4 0.64 304 58 583 0.24 5.59

1015.15 52 0.37 0.24 1.16 0.6 298 133 644 0.18 3.09

1015.2 51.3 1.15 0.84 1.36 0.58 387 171 278 0.49 6.91

1015.21 51.6 0.25 0.17 1.41 0.6 307 55 455 0.31 6.06

1015.24 50.5 0.15 0.13 1.15 0.52 348 57 500 0.23 5.9

1015.25 50 0.19 0.11 1.44 0.64 333 42 554 0.26 5.94

1015.3 51.2 0.28 0.2 0.9 0.59 300 80 360 0.25 3.2

1015.32 51 0.45 0.28 0.61 0.62 299 156 339 0.18 3.27

1015.35 51.8 2.18 1.02 1.3 0.68 308 144 183 0.71 6.65

1015.4 51.5 0.11 0.12 1.11 0.47 294 52 483 0.23 5.29

1015.45 52.7 0.07 0.1 1.13 0.38 333 40 452 0.25 6.66

1015.5 51.1 0.15 0.21 0.29 0.42 416 191 264 0.11 4.52

1015.55 52.6 0.18 0.33 0.77 0.35 377 80 188 0.41 1.74

1015.6 52.5 0.2 0.27 0.51 0.43 398 159 300 0.17 5.79

1015.65 51.8 0.84 0.57 0.57 0.6 396 158 158 0.36 5.99

1015.68 51.2 0.97 0.51 0.7 0.65 310 109 149 0.47 4.99

1015.7 50 0.17 0.17 0.4 0.5 319 212 500 0.08 3.24

1015.71 50.6 0.12 0.15 0.5 0.43 312 150 500 0.1 4.62

1015.75 53 0.12 0.16 1.65 0.43 368 40 412 0.4 6.3

1015.76 51.9 0.92 0.65 1.11 0.59 363 250 427 0.26 5.32

1015.79 50.9 0.2 0.2 0.96 0.51 609 65 310 0.31 4.89

1015.8 52.1 0.45 0.24 1.32 0.65 300 83 455 0.29 6.61

1015.81 52 1.77 0.9 1.17 0.66 322 180 234 0.5 5.51

1015.83 50.8 1.63 0.86 0.73 0.65 395 172 146 0.5 6.59

1015.85 52.2 1.75 0.91 1 0.66 393 118 130 0.77 9.43

1015.85 51.2 2.58 1.28 1.11 0.67 300 162 141 0.79 5.52

1015.86 51.2 2.41 1.12 1.28 0.68 374 175 200 0.64 7.25

1015.87 50.9 0.32 0.15 0.72 0.68 334 75 360 0.2 6.37

1015.88 52.9 0.75 0.29 0.56 0.72 333 66 127 0.44 10.16

43

1015.9 51.1 0.31 0.22 0.4 0.58 391 85 154 0.26 6.82

1015.92 52.7 1.85 0.91 1.01 0.67 331 121 135 0.75 9.52

1015.93 50.3 1.54 0.67 1.07 0.7 307 88 141 0.76 9.19

1015.95 52 4.53 2.2 0.35 0.67 327 234 37 0.94 7.19

1015.96 50.4 5.76 2.8 0.71 0.67 322 211 53 1.33 6.21

1015.98 52.8 5.97 2.55 0.96 0.7 323 189 71 1.35 7.63

1016 51.5 0.84 0.45 1 0.65 378 110 244 0.41 11.66

1016.02 50 7.45 3.18 0.45 0.7 305 254 36 1.25 5.91

1016.03 52.6 1.38 0.67 1.1 0.67 395 126 208 0.53 12.86

1016.04 51.3 4.92 2.03 0.99 0.71 306 209 102 0.97 8.58

1016.05 52.6 4.56 1.96 1.21 0.7 379 173 107 1.13 8.12

1016.06 50.3 1.75 0.81 1.33 0.68 399 125 205 0.65 10.67

1016.1 50.9 3.42 1.15 0.45 0.75 301 128 50 0.9 4.96

1016.11 50.3 1.95 0.86 0.8 0.69 395 183 170 0.47 8.46

1016.12 50.1 6.79 3.01 0.26 0.69 383 232 20 1.3 6.24

1016.13 52.8 7.08 3.13 0.69 0.69 306 209 46 1.5 5.08

1016.14 52 3.57 1.3 0.83 0.73 321 125 80 1.04 6.92

1016.15 51 7.61 2.93 0.55 0.72 328 174 33 1.68 5.66

1016.16 52.7 1.94 0.78 0.63 0.71 389 137 111 0.57 10.68

1016.18 52.4 1.4 0.66 1.19 0.68 390 116 209 0.57 13

1016.19 50.7 2.92 1.5 0.97 0.66 307 138 89 1.09 7.21

1016.2 53 1.16 0.56 0.64 0.67 309 124 142 0.45 2.85

1016.22 50 0.23 0.12 1.13 0.65 369 43 404 0.28 4.56

1016.24 50.1 0.26 0.15 0.59 0.63 374 56 219 0.27 3.19

1016.25 50.8 1.22 0.82 1.03 0.6 377 195 245 0.42 8.41

1016.27 51.6 0.35 0.33 0.47 0.52 366 97 138 0.34 5.92

1016.29 53 1.53 0.93 0.93 0.62 397 139 139 0.67 9.09

1016.3 51.8 1.1 0.72 1.35 0.6 324 124 233 0.58 8.27

1016.32 50.4 0.11 0.11 1.51 0.49 360 52 719 0.21 7.99

1016.33 52.1 0.11 0.1 1.22 0.51 335 16 194 0.63 4.88

1016.35 51 0.18 0.23 1.06 0.43 377 79 366 0.29 4.98

1016.36 52 0.18 0.14 1.29 0.57 336 48 445 0.29 4.84

1016.37 50.8 0.52 0.31 0.9 0.63 297 66 191 0.47 3.1

1016.38 51.1 0.8 0.38 1.07 0.68 302 84 238 0.45 3.49

1016.4 50.3 0.61 0.33 0.88 0.65 298 51 135 0.65 3.72

1016.42 51.3 2.83 2.18 0.97 0.56 392 240 107 0.91 7.11

1016.43 50 1.05 0.47 0.89 0.69 307 121 228 0.39 6.79

1016.44 51.4 0.07 0.06 1.4 0.57 331 20 467 0.3 11.73

1016.45 50.3 0.17 0.13 1.35 0.55 334 37 386 0.35 7.03

1016.47 50.3 0.14 0.12 1.39 0.54 365 41 479 0.29 12.57

1016.49 52.9 0.46 0.37 1.33 0.56 366 84 302 0.44 11.4

44

1016.5 51.6 0.12 0.06 1 0.67 347 15 250 0.4 10.5

1016.51 50.2 0.08 0.07 1.29 0.53 340 21 379 0.34 7.96

1016.53 50.2 0.1 0.1 1.69 0.5 348 27 457 0.37 7.58

1016.55 52 0.08 0.04 1.33 0.67 346 12 403 0.33 13.78

1016.58 50.7 0.07 0.05 1.42 0.58 349 19 526 0.27 9.65

1016.6 51.9 0.09 0.1 1.33 0.47 361 50 665 0.2 9.26

1016.62 51.6 0.33 0.2 0.58 0.63 345 69 200 0.29 3.34

1016.63 51.8 0.25 0.16 1.34 0.61 345 21 174 0.77 5.26

1016.65 50.1 0.09 0.08 0.96 0.54 362 30 356 0.27 7.42

1016.67 51 0.08 0.05 1.14 0.6 360 19 438 0.26 11.63

1016.69 50.1 0.07 0.08 1.65 0.44 362 53 110

0 0.15 7.04

1016.7 52.3 0.06 0.06 0.95 0.53 348 9 138 0.69 5

1016.73 51.6 0.08 0.07 1.19 0.54 354 23 384 0.31 12.27

1016.75 52.6 0.11 0.07 1.03 0.6 341 10 147 0.7 2.92

1016.76 52.2 0.13 0.08 1.09 0.63 340 12 170 0.64 2.96

1016.8 52.7 0.11 0.08 1.39 0.58 351 11 193 0.72 7.56

1016.82 52.8 0.21 0.14 1.49 0.6 367 20 216 0.69 6.96

1016.85 50 0.04 0.07 0.93 0.39 373 26 344 0.27 9.49

1016.9 52.1 0.08 0.06 0.91 0.57 353 4 61 1.48 7.54

1016.91 52.5 0.06 0.1 0.75 0.38 370 8 60 1.26 6.82

1016.93 50.2 0.07 0.03 1.06 0.7 340 14 482 0.22 13.02

1016.95 52.9 0.05 0.05 1.14 0.49 348 22 496 0.23 12.35

1016.96 51.7 0.05 0.06 0.93 0.43 359 4 67 1.39 9.32

1017 53 0.07 0.07 0.42 0.48 349 28 168 0.25 6.2

1017.03 51.6 0.08 0.04 1.06 0.65 334 15 408 0.26 10.59

1017.07 51.7 0.1 0.14 0.96 0.43 350 67 457 0.21 9.88

1017.1 51.3 0.09 0.13 0.89 0.41 347 81 556 0.16 9.85

1017.15 51.7 0.09 0.13 0.86 0.41 355 162 107

5 0.08 7.4

1017.2 50.6 0.07 0.16 0.17 0.32 341 145 155 0.11 7.59

1017.3 50.3 0.09 0.12 1.06 0.42 351 63 558 0.19 8.55

1017.4 52.1 0.12 0.12 0.54 0.5 344 40 180 0.3 7.95

1017.5 50.7 0.06 0.1 1.16 0.35 340 42 483 0.24 11.15

1017.6 50.4 0.09 0.11 0.8 0.45 347 28 200 0.4 8.47

1017.7 50 0.06 0.1 0.89 0.38 348 29 262 0.34 7.42

1017.8 50.8 0.07 0.1 1.13 0.39 341 38 435 0.26 9.23

1017.9 53 0.09 0.13 0.37 0.4 354 54 154 0.24 10.04

1018 51.1 0.11 0.12 0.93 0.48 362 32 251 0.37 8.02

1018.1 51.4 0.09 0.12 1.15 0.42 356 36 348 0.33 9.16

1018.2 50.9 0.08 0.1 0.92 0.44 347 59 541 0.17 10.14

1018.3 52.3 0.18 0.11 1.34 0.62 348 55 670 0.2 9.65

45

1018.35 51.4 0.18 0.14 1.17 0.57 365 54 450 0.26 8.92

1018.4 52.8 0.08 0.1 1.41 0.43 336 43 613 0.23 10.09

1018.45 50.9 0.07 0.14 0.83 0.35 348 67 395 0.21 10.82

1018.5 52.1 0.06 0.11 0.8 0.38 348 85 615 0.13 6.32

1019.5 50.6 0.08 0.1 0.54 0.44 338 91 491 0.11 6.26

1020.5 50.6 0.11 0.12 0.8 0.47 363 80 533 0.15 10.36

1021.5 52.8 0.1 0.11 0.75 0.48 346 58 395 0.19 16.11

1022.5 50.4 0.04 0.11 0.7 0.28 348 41 259 0.27 13.83

1023.5 50.2 0.16 0.14 0.68 0.55 351 34 166 0.41 12.85

1024.13 53 0.08 0.12 0.73 0.41 348 63 384 0.19 9.51

1024.5 51.3 0.1 0.19 0.15 0.36 419 112 88 0.17 8.83

1025.5 50 0.09 0.14 0.14 0.4 349 25 25 0.55 10.68

1026.5 50.1 0.1 0.17 0.42 0.37 354 40 100 0.42 9.59

1027.5 50.3 0.07 0.17 0.16 0.3 349 41 39 0.41 5.78

1048.5 51.6 0.15 0.16 0.4 0.48 364 84 211 0.19 8.71